TECH

April 23, 2026

ECR, ECS, vs EKS: Understanding AWS Containers

In the era of modern software development, packaging applications with Docker is just the beginning. When you have dozens or even hundreds of Microservices that need to run concurrently, auto-recover from failures, and scale in an instant, you need Container Orchestration tools.

In the AWS ecosystem, this challenge is perfectly solved by a trio of services: Amazon ECR (Storage), alongside two orchestration options, Amazon ECS and Amazon EKS. Understanding and choosing the right "conductor" will determine the success of your infrastructure architecture.

1. Amazon ECR (Elastic Container Registry): The Secure "Vault"

Before containers can run, they need a secure place to be stored. ECR is a fully managed container registry by AWS, similar to Docker Hub but tailored for the enterprise ecosystem.

  • Enterprise-Grade Security: Deeply integrated with AWS IAM. You can grant granular permissions down to each repository (e.g., Server A can only "pull", Developer B can "push").

  • Automated Image Scanning: ECR automatically scans for software vulnerabilities (CVEs) whenever a new image is pushed—a mandatory feature for healthcare (HIPAA compliant) or financial systems (PCI-DSS compliant).

  • Speed & Optimization: Thanks to AWS's internal network infrastructure, pulling images from ECR to ECS or EKS happens with near-zero latency.

Once images are ready on ECR, we face a crossroads: Should we choose ECS or EKS to run them?

2. Amazon ECS (Elastic Container Service): Simple, Fast & Optimized for AWS

ECS is the "native" container orchestration solution developed by AWS. The philosophy of ECS is to deliver maximum simplicity for users operating within the AWS ecosystem.

  • Low Learning Curve: If your team lacks Kubernetes experience, ECS is the perfect choice. Concepts like Task Definitions and Services in ECS are very straightforward to grasp.

  • Deep Integration: The biggest strength of ECS is its seamless cohesion with other AWS services (ALB, Route 53, CloudWatch, IAM).

  • The Power of AWS Fargate: Both ECS and EKS support Fargate (Serverless compute for containers), but the Fargate experience on ECS is significantly smoother and more seamless. You simply deploy the container, and AWS handles the entire underlying infrastructure.

3. Amazon EKS (Elastic Kubernetes Service): Unmatched Power & Industry Standard

If ECS is an easy-to-drive automatic car, EKS is an F1 racing car with countless customizable buttons. EKS is a managed Kubernetes (K8s) service—the open-source platform that currently serves as the global "gold standard" for container orchestration.

  • Massive Ecosystem: K8s boasts the largest open-source community. Thousands of tools (Helm, Prometheus, Istio, ArgoCD) are natively designed to run on K8s.

  • No Vendor Lock-in: Because EKS is fundamentally standard Kubernetes, you can easily "lift and shift" your entire system from AWS to Google Cloud (GKE), Azure (AKS), or even run it on physical servers (On-premise) without rewriting extensive configurations.

  • Maximum Flexibility: EKS allows you to deeply customize network configurations (Custom CNI), schedule containers (Advanced Scheduling), and manage complex resources.

4. Comparison Table: ECS vs. EKS

To easily visualize the differences, here is a quick comparison between the two services:

 Criteria  Amazon ECS  Amazon EKS
 Core Technology  AWS Proprietary  Open-source platform (Kubernetes)
 Complexity  Low - Easy to learn and operate  Very High - Requires specialized DevOps team
 Ecosystem  Integrated with AWS native tools  Massive open-source ecosystem (CNCF)
 Vendor Lock-in  High (Hard to migrate to other clouds)  Low (Easy to migrate across Multi-cloud/On-premise)
 Control Plane Cost  Free (Pay only for compute resources used)  ~$73/month per EKS Cluster
 Best Suited For  Startups, fast-to-market projects, AWS-centric teams  Large enterprises, Hybrid Cloud, Multi-cloud systems

 

5. Real-World Scenarios from ISB Vietnam

At ISB Vietnam, choosing an architecture depends entirely on the client's business problem:

  • Scenario 1 (Choosing ECS): An internal Business Management System needs rapid modernization from legacy to Cloud. The client wants the lowest maintenance costs, and their IT team has no K8s experts. Solution: ISB Vietnam consults using ECR + ECS Fargate. The infrastructure is spun up in days, auto-scales during business hours, and scales to zero at night to save costs.

  • Scenario 2 (Choosing EKS): A MedTech corporation needs to build a global wearable device data collection platform. A strict requirement is that the system must run partly on AWS and partly on the hospital's physical Data Center to comply with local data residency laws. Solution: ISB Vietnam utilizes EKS combined with Amazon EKS Anywhere. Kubernetes provides absolute consistency between Cloud and On-premise environments, while allowing the deployment of complex Service Mesh tools to encrypt healthcare data.

Key Takeaways

  • ECR: The secure vault for your Docker Images with built-in vulnerability scanning.

  • ECS: Optimized for speed and simplicity. Choose ECS if you want to focus on application code rather than managing infrastructure.

  • EKS: The industry standard. Choose EKS if your system is highly complex, requires multi-platform capabilities (Multi-cloud), and you have a robust DevOps team.

What's Next?

Both ECS and EKS are powerful, but they truly shine when deployed entirely via automation (Infrastructure as Code). In our next post, we will explore how to use Terraform to spin up these entire ECS/EKS clusters with just a single line of code.

In your organization, is your technical team leaning towards the "simplicity and ease of management" of ECS, or the "global standardization" of EKS? Share your system challenges in the comments below so we can discuss!

Whether your business needs to deploy a flexible system on ECS or build a complex Enterprise-grade EKS cluster, ISB Vietnam's team of experts is ready to design the perfect solution. Let’s build something great together—reach out to us today. Or click here to explore more ISB Vietnam's case studies.

 

References

[1]. Amazon Elastic Container Registry (ECR) Features. Retrieved from https://docs.aws.amazon.com/AmazonECR/latest/userguide/what-is-ecr.html

[2]. Amazon Elastic Container Service (ECS). Retrieved from https://docs.aws.amazon.com/AmazonECS/latest/developerguide/Welcome.html

[3]. Amazon Elastic Kubernetes Service (EKS). Retrieved from https://docs.aws.amazon.com/eks/latest/userguide/what-is-eks.html

Ready to get started?

Contact IVC for a free consultation and discover how we can help your business grow online.

Contact IVC for a Free Consultation
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April 23, 2026

How RAG Works: Lessons from a Junior Developer

Recently, while working on a project, I had the chance to explore how a Retrieval-Augmented Generation (RAG) system works. Before that, I mostly interacted with Large Language Models through APIs, without thinking too much about how they actually retrieve and use external information.

With the rapid development of LLMs, many people have begun asking AI questions rather than searching on Google. This is very convenient, but LLMs have an important limitation: They can only answer questions based on the data they have been trained on.

For example, if a model was trained in 2025, how will it know what happens in 2026? If we want it to respond with information from documents it has never seen before, how will it know?

That's why RAG systems come in. This article is the first part of a short series documenting what I learned while trying to build a RAG system locally.

The series is divided into three parts:

  • Part 1 - Understanding the RAG Pipeline.
  • Part 2 - Running RAG locally.
  • Part 3 - Challenges and lessons learned.

In this first part, we’ll walk through the basic architecture of a RAG system and understand how its main components work together.

Simplified RAG pipeline

Instead of relying only on what the model already knows, RAG allows the model to retrieve relevant information from external documents.

Although many variations of RAG architectures exist today, most of them revolve around three core components: Document ingestion, retrieval, and generation.

Document Ingestion

The first step in a RAG system is preparing the documents so the system can use them.

Document Parsing

The main job of a parser is to extract text from documents such as PDFs, Word files, or HTML pages. Currently, many tools support this: Docling (Python), Langchain Document Loader (Python/TypeScript), Apache Tika (Java), etc.

Text chunking

At its most basic, we can segment by chunk size. Why do we need to chunk? LLMs have a limited context window and cannot process an entire document at once. Just as we can't remember the entire contents of a file.

For example, a chunk size of 100 means splitting the document into smaller chunks of 100 characters each. More complex methods involve segmenting based on the document's structure and layout.

In practice, chunking strategies may vary depending on the document structure and the context window of the language model.

Document
┌───────────────────────────────┐
Employee Handbook
Employees must reset their passwords every 90 days.
Passwords must contain at least 8 characters.
Two-factor authentication is recommended.
└───────────────────────────────┘

                ↓
            Text Chunking

Chunk 1                  Chunk 2                  Chunk 3
┌────────────────┐   ┌────────────────┐   ┌────────────────┐
Employees must   │   │Passwords must  │   │Two-factor      │
reset passwords  │   │contain at      │   │authentication  │
every 90 days    │   │least 8 chars   │   │is recommended  │
└────────────────┘   └────────────────┘   └────────────────┘

Embedding

Since machines process numbers rather than raw text, we have to convert letters into numbers for them. Embedding is the process of converting text into vectors using an embedding model. These vectors allow the system to measure semantic similarity between the user query and document chunks.

Chunk 1
"Employees must reset their passwords every 90 days."
↓
Embedding
[0.21, -0.33, 0.81, 0.45, -0.12, ...]

Vector Database

After the embeddings are generated, they are stored in a vector database. Unlike traditional databases that store structured data, vector databases are designed to store vector representations and efficiently perform similarity searches. Once all document chunks are stored in the vector database, the system is ready to retrieve relevant information when a user asks a question.

Retrieval

This is the core of RAG technology. Instead of searching text traditionally, the system searches for document vectors that are closest to the query vector of the user query.

Query Embedding

Similar to the previously vectorized document chunks, when a user submits a question, that question will also be converted into a vector.

Always remember this: both query embedding and chunk embedding must use the same embedding model.

User Question:
How often should employees reset their passwords?

↓
Embedding
[0.18, -0.41, 0.72, ...]

Vector Search

To put it simply, imagine that all document embeddings are points in a multi-dimensional space. When a user asks a question, the query is also converted into a vector and placed in the same space. The system then searches for document vectors that are closest to the query vector.

But what do we mean by “closest”?

In practice, similarity between vectors is measured using mathematical metrics such as cosine similarity or dot product. These metrics help the system identify document chunks that are semantically similar to the user's question.

Top-k Relevant Chunks

The top-k retrieved chunks are then combined and sent to the LLM as context. The exact value of k can vary depending on the system and the model’s context window.

In simple terms, the system gives the model relevant pieces of text and asks it to answer the question based on that information.

Query:
"How often should employees reset their passwords?"

↓

Top-k Retrieved Chunks

┌──────────────────────────────┐
Chunk 12
Employees must reset passwords
every 90 days.
└──────────────────────────────┘

┌──────────────────────────────┐
Chunk 27
Passwords must contain at least
8 characters.
└──────────────────────────────┘

┌──────────────────────────────┐
Chunk 35
Two-factor authentication is
recommended for all accounts.
└──────────────────────────────┘

↓

Context sent to LLM

↓

Answer

Generation

Now it's time to ask this AI a question. This step works similarly to copying text from somewhere, giving it to the AI, and asking, "Hey, what's in here?”

Prompt Construction

Besides the retrieved context, we also need to provide the LLM with a clear instruction. A simple prompt structure usually contains the context, the user’s question, and an instruction telling the model to answer based only on the provided information. Something like this:

You are an assistant who answers questions based on the provided context.

Context:
Employees must reset their passwords every 90 days.
Passwords must contain at least 8 characters.
Two-factor authentication is recommended.

Question:
How often should employees reset their passwords?

Answer:

LLM will automatically fill in the answer.

Context - Question - Answer Generation

This is the final step of the RAG process. This step is simple: after the LLM receives the prompt and context, it uses that information to answer the question. This process helps reduce hallucinations by grounding the answer in retrieved documents. commonly seen in LLMs.

However, there is one important thing to note. The accuracy of the answer depends on two factors:

  • Was the previous document search step correct? If you give it the wrong information, of course, it will give the wrong answer.
  • Is LLM strong enough? Even large models have a limited context window, so the system must carefully choose how many chunks to include.

Key Takeaways

  • Retrieval-Augmented Generation (RAG) enables LLMs to answer questions using external documents rather than relying solely on training data.
  • The documents must undergo a process of being received and encoded as vectors before they can be used.
  • A vector database is where vectors are stored and searched.
  • When a user asks a question, the system retrieves the most relevant document segments within the database.
  • The retrieved chunks are then combined into context and sent to the LLM to generate the final answer.

What’s next?

In this article, we walked through the basic pipeline of a RAG system — from document ingestion to answer generation.

In Part 2 - Running a RAG system locally, I’ll share what happened when I tried to run a RAG system locally, including the tools I used and some practical limitations I encountered during development.

This article is part of a technical blog series from ISB Vietnam, where our engineering team shares practical insights and lessons learned from real-world projects.

References

https://www.mhlw.go.jp/toukei/itiran/roudou/monthly/30/3009p/3009p.html

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April 23, 2026

Why Your AI Is Only As Good As Your Prompts

I. The Trust Gap

     GenAI tools, such as ChatGPT, Claude, and Google Gemini have an immense potential to improve our quality of life and help out with a lot of global issues. Yet, there is a fairly strong and widely discussed consensus that GenAI can be inaccurate.

     A recent KPMG survey[1] with over 48,000 people globally shows that even though 66% of them use GenAI regularly, only 46% felt willing to trust AI systems. It’s because many people are relying on GenAI output without evaluating its accuracy, which led to mistakes in their work.

     In my opinion, the problem is often not the technology itself, but the way it’s being used. GenAI, without a doubt, is incredibly powerful, but the quality of its output depends heavily on the quality of the prompt users provide. Learning how to create a clear, specific, and well-structured command or request when working with GenAI is the key to unlock these tools real potential.

 

 

II. What is prompt Engineering?

     Prompt Engineering is the essential skill of designing and refining prompts to improve the output of GenAI systems. Because GenAI models respond based on the specific input they receive, a well-structured prompt allows you to:

  • Produce more detailed and relevant responses.
  • Significantly improve output accuracy.
  • Control the format and style of the final result.

 

 

III. Prompt Engineering Techniques.

     Now that we understand what Prompt Engineering is, let’s break down some of the widely used techniques to craft prompts[2].

1. Zero-Shot Prompting:

          This is a technique where you present a task to the AI model without providing any examples or task-specific demonstrations. Its accuracy relies heavily on the strength of the underlying foundation model. The more advanced and capable the foundation model, the more likely the AI is to produce accurate results.

          Zero-shot prompting is often more suitable for straightforward tasks or when a quick response is needed, even though it can still handle more complex tasks with varying reliability.

 

2. Few-Shot Prompting:

          This technique involves providing a few examples within the prompt to guide the AI’s output. Instead of training the model, you guide it during inference by providing specific contextual examples (input-output pairs).

          If you provide the AI with only one example, then this technique is also called “Single -shot” or “One-Shot Prompting”.

 

 

3. Chain-of-Thought (CoT) Prompting:

          This is a technique where you break a task into a sequence of intermediate reasoning steps. This helps the AI model process logic more effectively, leading to more structured and accurate results. You can trigger this by providing examples of step-by-step reasoning or by simply adding instructions like “Break this into steps”.

          However, CoT prompting should be used selectively, mainly for tasks that require multi-step reasoning, where accuracy matters more than speed. In simpler cases, forcing step-by-step reasoning may slow the AI down or introduce unnecessary verbosity.

 

 

IV. Conclusion

     GenAI effectiveness depends largely on how it is used. Rather than viewing them as unreliable, It’s more productive to see AI as a tool that requires skill and thoughtful interaction.

     Mastering AI communication is becoming an essential skill in today’s digital world. By crafting clear and structured prompts, users can unlock the full potential of GenAI and use it more confidently and responsibly in their work and daily lives.

     If you're eager to take your Prompt Engineering skill to the next level and apply them to impactful, real-world projects, ISB VIETNAM offers an environment where PassionsTeamworkInnovations, and continuous learning are part of our everyday work. Visit the official website now to learn more about our company services, and how you can become part of a team that values thoughtful, high-quality software engineering.

 

References:

[1] KPMG survey: https://kpmg.com/xx/en/our-insights/ai-and-technology/trust-attitudes-and-use-of-ai.html

[2] Inspired by: https://www.udemy.com/course/aws-ai-practitioner-certified/

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April 23, 2026

Introduction to Google Apps Script: Build Simple Automation with JavaScript

Google Apps Script (GAS) can transform your work. It helps you replace traditional Excel-based workflows by turning Google Sheets into a powerful task management system.

Currently, many teams struggle with task management. Often, tasks get assigned but no one knows who is doing what. Consequently, reports take hours to compile. Moreover, repetitive follow-ups drain your time and lead to human error.

What if you could turn Google Sheets into a real task management system? You can do this without building a complex backend.

This is exactly where this serverless platform becomes a game changer. So, let’s explore how it works in a real business case.

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TECH

April 23, 2026

Microsoft 365 Login with ExpressJS

Identity is one of the most important security layers of modern systems. Modern apps must connect to numerous services, making a centralized and stable login system essential.

In this context, Microsoft 365 login is a logical choice for enterprise systems. Azure provides a standardized identity platform, eliminating the need to build authentication mechanisms from scratch.

Overall

At the high level, ExpressJS only acts as the client. Azure AD is the main entity, acting as the identity provider. The browser only handles redirects, while all sensitive processing, such as exchanging code for tokens, takes place in the backend.

The basic flow would be:

User → ExpressJS → Microsoft login → ExpressJS callback → session creation

Most importantly, the token never appears on the frontend. This is extremely important from a security perspective.

Setting up Azure AD

First, create a new application in Azure Active Directory via the Azure Portal.

Then create a Client Secret. Simply put, this is the "password" for the backend.

Finally, we will have three values; these three are the backbone of the entire login process:

  • Client ID – app identifier
  • Tenant ID – organization identifier
  • Client Secret – backend authentication

MSAL node configuration

Microsoft provides @azure/msal-node so developers don't have to manually code OAuth2. MSAL handles the headaches of code generation, token changes, token caching, and token refresh.

Installation:

npm install express @azure/msal-node express-session dotenv

Basic configuration:

// msalConfig.js

require("dotenv").config();

module.exports = {

    auth: {

        clientId: process.env.CLIENT_ID,

        authority: "https://login.microsoftonline.com/" + process.env.TENANT_ID,

        clientSecret: process.env.CLIENT_SECRET

}};

The Authority URL simply tells MSAL which tenant we are authenticating with.

After defining the config, we will create the other file to initialize the instance to use in the project

// msalClient.js

const { ConfidentialClientApplication } = require("@azure/msal-node");
const msalConfig = require("../config/msalConfig");

const cca = new ConfidentialClientApplication(msalConfig);

module.exports = cca;

Scope: Request only what we need

Scope refers to access permissions. It determines what the app can do on behalf of the user.

Here are some common scopes:

  • user.read – read basic profiles
  • mail.read – read email
  • files.read – read OneDrive files

The first time a user logs in, they will see a consent screen. This is very good, as it helps them know what permissions the app is requesting.

Actual login flow

Here, we use the OAuth2 authorization code flow – almost the default standard for backends.

The token is not exposed to the frontend. There is a refresh token widely accepted by enterprises

Route /login

const cca = require("./services/msalClient"); 

app.get("/login", async (req, res) => {

   const url = await cca.getAuthCodeUrl({

     scopes: ["user.read"],

     redirectUri: "http://localhost:3000/redirect"

    });

   res.redirect(url);

 });

This route only serves to redirect the user to the Microsoft login page.

Note: The redirectUri in the code must match the Redirect URI declared in Azure AD.
If they don't match, the login will fail.

Route /redirect

const cca = require("./services/msalClient"); 

app.get("/redirect", async (req, res) => {

   const tokenResponse = await cca.acquireTokenByCode({

     code: req.query.code,

     scopes: ["user.read"],

     redirectUri: "http://localhost:3000/redirect"

   });

   req.session.user = tokenResponse.account;

   req.session.accessToken = tokenResponse.accessToken;

   res.redirect("/dashboard");

 });

This is the main processing point: the backend exchanges the code for a token and then saves the session.

Sessions and Middleware

After establishing the session, protecting the route with middleware is all we need to do.

 function requireAuth(req, res, next) {

   if (!req.session.user) {

     return res.redirect("/login");

   }

   next();

 }

Conclusion

Microsoft 365 login is becoming the standard for modern enterprise systems. Instead of managing users, passwords, and complex security rules ourselves, we can directly use Azure Active Directory as a trusted identity provider.

In practice, this offers better security, less maintenance, and a login system that can scale across the organization without significant changes.

Whether you need scalable software solutions, expert IT outsourcing, or a long-term development partner, ISB Vietnam is here to deliver. Let’s build something great together—reach out to us today. Or click here to explore more ISB Vietnam's case studies.

[References]

  1. https://learn.microsoft.com/en-us/entra/identity-platform/quickstart-register-app
  2. https://learn.microsoft.com/en-us/entra/identity-platform/tutorial-v2-nodejs-webapp-msal
  3. https://www.freepik.com/free-photo/email-messages-network-circuit-board-link-connection-technology_1198384.htm (Image source)
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April 23, 2026

Mastering Burp Suite: Are you really getting the most out of it for your web security testing?

In the world of software testing, if automation tools ensure that a system works, then Burp Suite ensures that the system cannot be broken. As we move further into the era of complex architectures like UI-BFF-API, simply checking features is no longer enough. To truly level up your career, you must master the gold standard of security testing: Burp Suite.

But what makes this tool so indispensable? Let’s dive into its most effective applications.

  1. The Core Power: Intercepting Proxy

The most effective and fundamental application of Burp Suite is its Intercepting Proxy.

How it works: Burp Suite sits between your browser and the server. When you click Submit, Burp catches the request. This allows you to pause, inspect, and modify the data before it ever reaches the server. Why is this a "Game Changer" for Testers?

  • Bypassing Front-end Validation: You can bypass UI restrictions (like disabled buttons or character limits) to see if the Server-side is truly secure.
  • Parameter Tampering: Have you ever wondered what happens if you change a product price from $1,000 to $1 during checkout? With the Proxy, you can test this in seconds.  
  • Broken Access Control: In a multi-site system (Candidate, Parent, Admin), you can swap authorization tokens to see if a Parent can sneak into the Admin panel.

  1. Top 3 Features to Supercharge Your Testing

Beyond intercepting traffic, Burp Suite offers specialized modules that act like superpowers for a QC:

  • Repeater: Unlimited Experimentation

Instead of re-loading the web page and re-filling forms, Repeater allows you to send the same request over and over with different modifications. It’s the fastest way to pinpoint logic flaws and edge cases.

  • Intruder: Automated Attacks

Need to test 1,000 different password combinations? Or check for IDOR (Insecure Direct Object Reference) by cycling through 500 different User IDs? Intruder automates these repetitive tasks, saving you hours of manual work.

  • Scanner (Pro Version): Automated Vulnerability Detection

For busy QCs, the Scanner automatically crawls the application to find common vulnerabilities like SQL Injection, XSS, and Security Misconfigurations while you focus on more complex testing scenarios.

  1. Applying Burp Suite to the UI-BFF-API Model

In your daily work with the UI-BFF-API architecture, Burp Suite becomes a surgical tool:

  • Testing the BFF Layer: Ensure that the Backend-for-Frontend is properly filtering sensitive data before sending it to the UI.
  • Role-Based Testing: With four distinct sites (Candidate, Parent, University Admin, System Admin), Burp makes it easy to manage multiple sessions and ensure that users stay within their permitted boundaries.
      1. Tips for Junior QCs Starting with Burp Suite

      Don’t let the complex interface intimidate you. Here is how to start:

      • Learn Proxy Configuration first: This is your gateway to understanding how the web talks.
      • Monitor the HTTP History: Simply observing the flow of requests and responses will teach you more about web architecture than any textbook.
      • Ethics First: Always use Burp Suite in a staging/UAT environment. Never use it on a production system without explicit permission.

      Would you like me to create a Quick Start Guide for configuring Burp Suite with your UI-BFF-API application?

      To test an architecture consisting of an Exam Candidate, Parent, and Admin sites, you need to see exactly how the UI talks to the BFF (Backend-for-Frontend).

      Step 1: The Basic Connection (The Proxy)

      1. Launch Burp Suite: Open the application and select Temporary Project.
      2. Use the Built-in Browser: Go to the Proxy tab > Interceptor sub-tab > Click Open Browser
        • Why? This is much easier than configuring Firefox or Chrome manually, as Burp handles the SSL certificates for you automatically.
      3. Turn Intercept off: For now, keep it off so you can browse the sites freely while Burp records the history in the background. 

        Step 2: Organize Your Scope (Crucial for 4 Sites)

        Since you are working with four different sites, your history will get messy quickly.

        1. Go to the Target tab > Scope sub-tab.
        2. Add the URLs of all four sites (e.g., https://candidate.example.com, https://admin.example.com).
        3. Go to the Proxy tab > HTTP History.
        4. Click the Filter bar at the top and check Show only in-scope items.
          • Result: You will now only see traffic related to your project, hiding background noise like Windows updates or Google analytics.

        Step 3: Mapping the UI-BFF-API Flow

        1. Open your Candidate Site in the Burp Browser and perform a Login.
        2. Look at the HTTP History. You will see a request going from the UI to the BFF.
        3. The Secret Sauce: Right-click that Login request and select Send to Repeater.
        4. In Repeater, you can now manually change the username or password and hit Send to see how the BFF responds without re-typing anything in the browser.

        Step 4: Testing Roles (The Parent vs. Admin Test)

        This is the most effective test for your specific architecture:

        1. Log in as a Parent in the browser.
        2. Find a request in the history that fetches Parent Data from the BFF. Look for the Authorization: Bearer <TOKEN>
        3. Now, try to access an Admin API URL by pasting it into the Repeater.
        4. If the BFF returns 200 OK instead of 403 Forbidden, you've found a Critical Security Bug!

        Finally, if AI is the assistant that helps you write test cases faster, Burp Suite is the microscope that helps you find the invisible bugs that could destroy a company’s reputation. By mastering Burp Suite, you transition from a standard Tester to a Security-Aware Quality Engineer.

        Whether you need scalable software solutions, expert IT outsourcing, or a long-term development partner, ISB Vietnam is here to deliver. Let’s build something great together—reach out to us today. Or click here to explore more ISB Vietnam's case studies.

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        April 23, 2026

        When Should You Use ADO.NET vs Entity Framework?

        When developing applications with the .NET platform, developers often face a common question: Should we use ADO.NET or Entity Framework for database access? Both technologies are widely used in the .NET ecosystem and each has its own strengths. Choosing the right one can significantly impact performance, maintainability, and development speed. In this article, we’ll explore the differences and discuss when you should use ADO.NET and when Entity Framework is the better choice.

        Understanding ADO.NET

        ADO.NET is the traditional data access technology used in .NET applications. It provides low-level access to databases and requires developers to write SQL queries manually.

        Typical components include:

        • SqlConnection
        • SqlCommand
        • SqlDataReader
        • DataTable
        With ADO.NET, developers have full control over how queries are executed and how data is retrieved.

        Advantages of ADO.NET

        • ✅ High performance
        • ✅ Full control over SQL queries
        • ✅ Suitable for complex database operations

        Disadvantages

        • ❌ More boilerplate code
        • ❌ Manual mapping between database tables and objects
        • ❌ Harder to maintain in large applications

        Understanding Entity Framework

        Entity Framework (EF) is an Object-Relational Mapper (ORM) developed by Microsoft.

        Instead of writing SQL queries, developers interact with the database using C# objects and LINQ queries.

        Example:

        var users = context.Persons.Where(u => u.Age > 18).ToList();

        Entity Framework automatically converts this into SQL and executes it against the database.

        Advantages of Entity Framework

        • ✅ Faster development
        • ✅ Cleaner and more readable code
        • ✅ Automatic object-relational mapping
        • ✅ Strong integration with LINQ

        Disadvantages

        • ❌ Potential performance overhead
        • ❌ Less control over generated SQL
        • ❌ Not always optimal for complex queries

        When Should You Use ADO.NET?

        1. When Performance Is Critical

        If your application processes large volumes of data or requires extremely optimized queries, ADO.NET is often the better choice. Examples:
        • Financial systems
        • High-traffic enterprise applications
        • High-traffic enterprise applications
        • Batch processing systems
        Because SQL is written manually, developers can optimize queries precisely.

        2. When Working with Complex Queries or Stored Procedures

        Some database operations involve:
        • Advanced joins
        • Complex stored procedures
        • Custom indexing strategies
        ADO.NET allows developers to execute and optimize these queries directly.

        3. When Maintaining Legacy Systems

        Many older .NET applications were built using ADO.NET.

        If you are maintaining or extending an existing system, continuing to use ADO.NET may be more practical than refactoring everything to an ORM.

        When Should You Use Entity Framework?

        1. When Rapid Development Is Important

        Entity Framework significantly reduces the amount of code needed for common operations.

        It is ideal for:

        • Web APIs
        • Internal business applications
        • Startup or MVP projects
        Developers can focus on business logic rather than SQL queries.

        2. When Your Application Has a Strong Domain Model

        If your application contains many business entities like:

        • Users
        • Orders
        • Products
        • Invoices
        Entity Framework helps map these entities directly to database tables, making the architecture more intuitive.

        3. When Maintainability Is a Priority

        Entity Framework improves:

        • Code readability
        • Maintainability
        • Developer onboarding

        New developers can understand the system faster because the code closely reflects the domain model rather than raw SQL.

        Best Practice: Use Both

        In many modern projects, teams combine both approaches.

        A common strategy is:

        • Entity Framework → for standard CRUD operations
        • ADO.NET or raw SQL → for performance-critical queries

        This hybrid approach balances development productivity and performance optimization.

        Conclusion

        There is no one-size-fits-all solution.

        • Use ADO.NET when performance and SQL control are critical.
        • Use Entity Framework when you want faster development and easier maintenance.

        Understanding when to use each technology will help you design scalable, efficient, and maintainable .NET applications.

         

        Whether you need scalable software solutions, expert IT outsourcing, or a long-term development partner, ISB Vietnam is here to deliver. Let’s build something great together—reach out to us today. Or click here to explore more ISB Vietnam's case studies.

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        TECH

        April 23, 2026

        Implementing Access Tokens and Refresh Tokens "The Right Way"

        Implementing Access Tokens and Refresh Tokens is the gold standard in modern authentication (especially with JWT - JSON Web Tokens). The goal is to balance security and user experience.
        Below is a detailed guide on how to use these two token types "correctly" and most securely.

        1. Why do we need 2 types of tokens?

        Why not use a single token with a permanent expiration? Because if a hacker obtains that token, they gain access forever. We split them into two to minimize risk:
        Feature
        Access Token (AT)
        Refresh Token (RT)
        Purpose
        Access resources (API)
        Request a new Access Token
        Lifespan
        Very short (15 minutes - 1 hour)
        Long (7 days - 30 days)
        Storage Type
        Stateless (usually JWT)
        Stateful (stored in DB/Redis for control)
        Risk
        If lost, the hacker can only use it for a short time
        If lost, consequences are more serious (but it can be revoked)

        2. Standard Workflow (The Flow)

        Here is the standard lifecycle of this authentication mechanism:
        1.Login: User sends User/Pass. Server authenticates and returns an AT and RT pair.
        2.Storage: Client stores AT and RT in a secure place (see section 3).
        3.Send Request: Client sends a request with AT in the Header (Authorization: Bearer <token>).
        4.Expired:
        - Server checks AT. If expired -> Returns 401 Unauthorized error.
        -  Client receives 401 error -> Automatically sends a /refresh-token request with RT to the Server.
        5.Renewal:
        * Server checks RT (is it valid? is it blacklisted?).
        * If valid -> Server returns a new AT (and usually a new RT - see Token Rotation section).
        6.Retry: Client uses the new AT to retry the original request without the user realizing it happened.

        3. Storage "Best Practices"

        This is the most important part to avoid security vulnerabilities (XSS and CSRF).

         A. For Web Applications (SPA - React, Vue, Angular)

        The common way is to save to `localStorage`, but the safest way is:

         

        Access Token: Store in JavaScript local variable (in-memory).
        Pros: XSS attackers cannot read the token (because it is not in storage).
        Cons: Token is lost when the page is refreshed (F5) (solved by silently calling a refresh token API immediately upon page load).

         

        Refresh Token: Store in HttpOnly Cookie.
        Cookie configuration: HttpOnly (JS cannot read), Secure (sent only over HTTPS), SameSite=Strict.
        Pros:* Completely immune to XSS. Hackers cannot copy this token.

         

        B. For Mobile Apps (iOS/Android)

        Store both in the operating system's secure storage.
        iOS: Keychain.
        Android: EncryptedSharedPreferences / Keystore.

        4. Token Rotation Mechanism

        To enhance security, you should not use the same Refresh Token forever. Use the Refresh Token Rotation technique:

        1. Every time the Client uses Old_RT to request a new token.
        2. The Server will return New_AT and New_RT.
        3. The Server marks Old_RT as used (or deletes it) in the Database.
        4.Theft Detection: If a hacker steals Old_RT and tries to use it to refresh -> The Server sees that Old_RT has already been used -> The Server immediately revokes all RTs related to that user, forcing the user to log in again.

        Conclusion

        1. Access Token short, Refresh Token long.
        2. Web: Prioritize HttpOnly Cookie for Refresh Token, In-memory for Access Token.
        3. Mobile: Use Keychain/Keystore.
        4. Backend: Always validate Refresh Token in the database (to allow revocation/revoke when needed).
        5. Rotation: Change to a new Refresh Token after every use.

        Whether you need scalable software solutions, expert IT outsourcing, or a long-term development partner, ISB Vietnam is here to deliver. Let’s build something great together—reach out to us today. Or click here to explore more ISB Vietnam's case studies.

        [References]
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        TECH

        March 9, 2026

        Data Masking Guide: How to Protect Sensitive Data Before Using AI

        In the era of ChatGPT, Gemini, and Claude, copying and pasting data to solve problems has become a habit. However, behind this convenience is a huge security risk. Data Masking is no longer just an option; it is a vital skill to protect your career and your company’s reputation.

        1. The Temptation and the "AI Trap"

        Many employees copy-paste error logs or customer emails into AI to get fast results. The danger is that AI learns from this data and might accidentally reveal it to other users later.

        According to security experts, the Samsung data leak (where engineers pasted secret code into ChatGPT) is a big lesson. At ISB Vietnam, we believe Data Masking is a mandatory skill before you hit "Enter" on any AI tool.

        2. What is Data Masking?

        Data Masking is the process of hiding sensitive data by changing original letters and numbers.

        The goal is to create a "fake" version of the data that keeps the same structure. This way, the AI can still understand the logic and fix the error, but it won't know the real identity of the person or the business.

         

        3. The "Danger Zone": 6 Types of Data You Must Never Paste

        Before talking to AI, check this list and mask these items:

        No.

         Data Type

         What’s Included (Examples)

        1

         Personally Identifiable Info (PII)

         Full names, addresses, phone numbers, ID/Passport numbers, personal emails.

        2

         Financial & Banking Data

         Credit card numbers, bank accounts, transaction history, payment credentials.

        3

         Trade Secrets & Business Info

         Proprietary algorithms, strategic plans, upcoming product specifications.

        4

         Biometric Data

         Fingerprints, facial recognition, retina scans, voiceprints.

        5

         Medical & Health Records

         Patient histories, prescriptions, diagnostic details, health insurance info.

        6

         Private Ideas & IP

         Unpublished research, confidential brainstorming, creative intellectual property.

         

        4. Practical Data Masking Techniques

        A. Popular Data Masking Techniques

         Method

        How it works

        Best used for

         Substitution

         Replaces real data with similar but fake values (e.g., replace a real name with a name from a random list).

         Names, Credit card numbers.

         Randomization

         Replaces sensitive data with totally random values that have no connection to the original.

         Addresses, PII.

         Shuffling

         Mixes the values within the same column. The data is real, but it now belongs to the wrong records.

         Maintaining statistical relationships.

         Encryption

         Uses algorithms to turn data into an unreadable format. Only people with a "key" can read it.

         High-level security (but can slow down analysis).

         Hashing

         Converts data into a fixed-length string of random characters. It cannot be reversed.

         Passwords or data verification.

         Tokenization

         Replaces data with a "token" (reference value). The real data is stored in a separate, secure vault.

         Sensitive production data & Compliance.

         Nulling (Blanking)

         Replaces data with a "null" value or a blank space. It simply removes the information.

         Removing data while keeping the format.

         

        B. For Tech Staff - Automation

        Developers can use Regex or libraries like Faker (Python/JS) to clean error logs before querying AI. Here is a quick example:

         

        5. Static vs. Dynamic Masking

        AWS defines two main types of masking:

        • Static Data Masking (SDM): Masking a fixed set of data before it is stored or shared. Ideal for creating Testing environments.
        • Dynamic Data Masking (DDM): Masking data in real-time as it is queried. Perfect for Customer Support systems where access is based on user roles.

        Conclusion

        Think of an AI chat box like a stranger on the street. Would you shout your bank password to them? If not, don't paste it into AI without masking it first.

        At ISB VIETNAM, we follow strict security standards to ensure your code and data are always safe. Are you looking for a trusted outsourcing partner with professional security workflows?

        [Contact ISB VIETNAM today for a secure software solution!]

        Or click here to explore more ISB Vietnam's case studies

        Have you ever accidentally pasted sensitive data into AI? Let us know in the comments how you handled it!

         

        References

        https://aws.amazon.com/what-is/data-masking/

        https://www.linkedin.com/pulse/6-types-data-you-should-never-mention-ai-mekari-4timc

        Image from Gemini

         

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        TECH

        February 27, 2026

        How to Optimize jqGrid for Large Datasets

        I. Introduction

        In enterprise systems, displaying large datasets in tables is common. However, performance problems appear when the dataset grows to millions of records. Therefore, without proper optimization, system performance gradually declines.

        This article examines the following aspects:

          • Common performance problems in grid components handling large datasets.
          • The root causes of these issues.
          • Practical optimization strategies for production environments.

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