S_A_A_Tech

If you need IELTS materials, here is it...

You carry a tracking device every day. Airplane mode doesn’t stop it. Location off doesn’t stop it. Here’s how to disappear digitally:

A complete SaaS payment flow involves much more than just charging a card. To help you build one, in this guide Magnus shows how to connect Stripe Checkout, webhooks, and transactional emails. You’ll learn how to handle successful payments, async events, and automated user communication. freecodecamp.org/news/saas-paym…

API rate limiters restrict the number of requests a client can make to an endpoint in a specific period of time. This helps manage costs of using external APIs, blocks excessive requests from Denial of Service attacks, and so on. In this guide, @orimdominic_ explains how rate limiters work and helps you build your own with Next.js. freecodecamp.org/news/how-to-bu…

Why Fintech Apps Care About “What Happened,” Not Just “What Is” CQRS + Event Sourcing. Powerful, But Don’t Use It Everywhere

When you hear "real-time", you might think of websockets or instant refreshes on web app dashboards. But the systems engineering definition is a bit different - and focuses primarily on predictability. In this guide, you'll learn what real-time systems are (and what they're not) and how to build a soft real-time system in Go + React. freecodecamp.org/news/real-time…

Platforms like Notion or Webflow can serve thousands of users from one codebase – but how? Here, Michael explains how multi-tenancy works. You'll build a multi-tenant SaaS with Next.js, Express, and Prisma and create isolated user sites, dynamic routing, and a single scalable backend. freecodecamp.org/news/how-to-bu…

Monorepo microservices often need smarter CI/CD than just “rebuild everything.” In this tutorial, Tarikul helps you build a pipeline that detects changes and redeploys only affected services. He covers Jenkins, Docker, Traefik, and a full production-style setup on a Linux server. freecodecamp.org/news/build-pro…

How to micromanage your micromanager:

JOB INTERVIEW: "Why should we hire you?" Most candidates say: "Because I am a hard worker, a fast learner, and I am incredibly passionate about your company's mission!" (anchoring to generic begging) THE WINNING ANSWER ↓↓↓

I have 12 years of experience and working as a Principal Engineer @Atlassian and I have seen concurrency scaring the hell out of a lot of junior engineers. It’s one of the most feared topics in system design & backend interviews — race conditions, deadlocks, thread pools… you name it. But once you internalize these 20 must-know concepts, everything clicks. Save this thread. Read till the end. Your future interviews and production systems will thank you.

Most important Backend topics to revise before interviews (save this) : 1. API Design & HTTP Fundamentals - REST principles, CRUD mapping - HTTP methods (GET, POST, PUT, DELETE, PATCH) - Status codes (200, 201, 400, 401, 403, 404, 500) - Idempotency, headers, query vs params - Pagination, filtering, versioning 2. Authentication & Authorization - JWT (access vs refresh tokens) - Sessions vs cookies - OAuth basics (Google login flow) - Role-based access control (RBAC) - Password hashing (bcrypt) 3. Databases (VERY IMPORTANT) - SQL vs NoSQL (when to use what) - Joins, indexing, normalization - Transactions & ACID properties - Query optimization (avoid N+1 queries) - Schema design & relationships 4. Caching & Performance - Why caching is used - Redis basics (key-value, TTL) - CDN concept - Cache invalidation strategies - Reducing DB calls 5. System Design Basics - How to design scalable systems - Load balancing (horizontal vs vertical scaling) - Rate limiting - CAP theorem basics - High availability vs consistency 6. Server & Runtime Concepts - How backend actually works (request → server → DB → response) - Node.js event loop (callbacks, promises, async/await) - Blocking vs non-blocking I/O - Thread vs process basics 7. Error Handling & Logging - Try/catch, global error handlers - Logging levels (info, warn, error) - Debugging production issues - Monitoring basics 8. Security Fundamentals - Hashing vs encryption - SQL Injection, XSS, CSRF - Rate limiting & brute-force protection - HTTPS, CORS basics - Environment variables & secrets 9. Architecture Patterns - Monolith vs Microservices MVC pattern - Service layer, controllers, routes - Clean code & separation of concerns 10. Message Queues & Async Processing - Why queues are needed - Basics of Kafka / RabbitMQ - Background jobs (emails, notifications) 11. File Handling & Storage - Uploading files - Cloud storage (S3 basics) - Handling large files efficiently 12. Testing & Deployment - Unit testing vs integration testing - API testing (Postman) - CI/CD basics - Docker basics (containers) - Deployment flow (build → test → deploy) Most candidates prepare frameworks. Top candidates understand how systems actually work. That’s the difference between: “Can build APIs” vs “Can build scalable products.”

Interview questions HR will never skip:

A guy I know went for a backend role thinking he was ready. First question they asked: “What happens when two users try to update the same data at the same time?” He froze. Not because he hadn’t seen it… but because he never understood it deeply. So here are backend concepts explained simply. Save this. You’ll need it.

@Akintola_steve Link please

Good morning everyone, I’m kicking off a 90-day learning sprint where we’ll be building real projects, collaborating, and growing together as engineers. You won’t be restricted to a single tech stack. You’ll be grouped with others based on your preferred programming language so you can build with what you’re comfortable with. Once groups are formed, each person should create a GitHub repository that will be used throughout the 90 days. The goal is to work in teams of 10. This isn’t just about coding, it’s about learning how to actually work in a team. Each group will have clear monthly targets, and you’ll collaborate, build, and consistently push your progress to your repository. For the first month, we’ll focus on building a solid authentication system. The aim is to implement a proper, real-world authentication flow. I’ll share a reference we’ll follow, and add more where necessary. If you haven’t joined the WhatsApp group yet, check the comment section and ask any of my mutuals for the link. Let’s get to work.

Stop saying "Sorry for the delay" in your work emails. Here are 15 professional alternatives you can steal:

If your manager unexpectedly puts you on a Performance Improvement Plan (PIP), do not sign it immediately. Do not argue. Do not quit quietly. Execute these 18 steps immediately to flip the leverage:

The database that gaslights your users. No errors, no alerts, no 500s. Just a system that quietly lies to the people using it. Retweet, bookmark then Let’s read.

DURING JOB INTERVIEW: "Why are you leaving your current role?" Most candidates say: "I am looking for more growth opportunities and a better company culture." THE WINNING ANSWER:

Your Android phone’s storage is full. You delete photos, videos, apps. It’s still full. Because it’s not the visible files that are eating up your storage. Most of it is the HIDDEN junk that Android never tells you about. I cleaned mine yesterday and got 23GB back without deleting a single photo. Here’s how:

Why 95% of Candidates Get Rejected in Interviews (and How to Avoid It)...