Nilanshu | Building AlgoRadar

Yay Finally crossed 100 users, Thank You!

Developers say they want to learn backend development… …but then they try to learn servers, databases, auth, APIs, Docker, cloud, and security all at once. That’s exactly why they get stuck. Backend gets easier when you learn it in the right order. Here’s the roadmap I’d follow to learn backend development from zero:

Don’t overcomplicate it. • Build a Password Manager to learn file handling, hashing (not full crypto) • Build a URL Shortener to understand routing, IDs, and persistence • Build a Todo App with deadlines to practice CRUD and basic state • Build a Web Scraper to learn requests, parsing, and rate limits • Build a CLI Expense Tracker to master logic, files, and edge cases • Build a Log Analyzer to work with files, timestamps, and patterns • Build a Simple Recommender using similarity rules (not ML magic) • Build an Email Automation Script using SMTP and scheduling

As a Backend Engineer. Please learn: * API Design / Versioning / Idempotency * SQL / Indexing / Query Optimization * Caching / Invalidation / Redis * Message Queues / Kafka / RabbitMQ * Rate Limiting / Backpressure * Distributed Tracing / Observability * Load Balancing / Reverse Proxies * Consistency / Replication / Sharding This is where seniority starts.

Extremely underrated programming resources - The Missing Semester of Your CS Education - Computer Systems: A Programmer’s Perspective (CSAPP) - Visualgo. net - Beej’s Guide to Network Programming - Beej’s Guide to C Programming - The Odin Project - javascript. info - Real Python - DataEngineering. wiki - Learn Git Branching

As a backend engineer. Please learn: - SOLID design principles - Multithreading - Immutability - Streaming , messaging - Caching - Security - SSL, JWT, OAuth - factory, decorator, singleton, obeservable design patterns - TDD All very important topics .

As a system design interviewer, I would expect a Senior Engineer to clearly know the difference between: Caching vs buffering Rate limiting vs throttling Replication vs sharding Failover vs fallback Strong consistency vs eventual consistency Queue vs stream Horizontal vs vertical scaling Timeout vs retry vs circuit breaker How many can you explain properly?

I have 12+ years of experience in backend engineering and now work as a Principal Engineer. One thing I’ve noticed is this: A lot of engineers want to become “backend architects” because the title sounds cool. But very few actually understand what that role requires. It is not just: - knowing Kafka - drawing boxes in interviews - saying “let’s use microservices” - or memorizing CAP theorem If you want to become one, here are 10 areas you need to learn well:

You don’t struggle with distributed systems because they’re hard. You struggle because you skipped the prerequisites. After my last post on DS a few of the people asked: “Where should I start?” Here’s what you actually need before touching distributed systems, a thread👇

90% of microservices interviews are basically these 7 questions.

Backend development is “simple” as long as you understand these fundamentals: HTTP basics • Methods • Status codes • Request and response headers Security & identity • Authentication vs authorization • JWTs, sessions, and cookies • OAuth 2.0 • Password hashing (bcrypt / Argon2) • Salting and peppering • 2FA and SSO • RBAC and ABAC API fundamentals • API design principles • RESTful APIs • GraphQL • WebSockets • API versioning • Rate limiting and throttling • Pagination, filtering, and sorting • File uploads and streaming Server concepts • Middleware • Error handling • Logging and monitoring • APM (performance monitoring) • Server-side rendering Databases • Database design • SQL and NoSQL • Indexing and query optimization • ACID properties • CAP theorem • Normalization vs denormalization • ORMs • Connection pooling • Transactions, migrations, and seeding Caching & performance • Caching strategies • Redis and Memcached • CDN integration Scalability & architecture • Load balancing • Horizontal vs vertical scaling • Monoliths, microservices, and SOA • Message queues and Pub/Sub • Event-driven systems • CQRS and Saga patterns • API gateways and service mesh Infrastructure & DevOps • Docker containers • Kubernetes orchestration • CI/CD pipelines • Environment variables • Configuration and secrets management Security hardening • CORS • CSRF protection • XSS prevention • SQL injection prevention • Input validation and output sanitization Background processing • Background jobs • Cron jobs and schedulers • Worker processes Concurrency & runtime • Async/await • Promises and callbacks • Thread pools • Process and memory management • Garbage collection Quality & tooling • Testing (unit, integration, E2E) • Mocking and stubbing • API documentation (Swagger / OpenAPI) • Postman or Insomnia • Git and version control • Code reviews • Debugging and benchmarking Production • Deployment strategies • Monitoring in production Once you grasp these, backend stops being “mysterious” and starts becoming systematic.

10 backend security concepts every dev should understand: 1. Authentication vs Authorization 2. JWT (stateless auth, but risky if misused) 3. OAuth2 / OpenID Connect 4. Rate limiting (protect against abuse) 5. CORS (browser boundary control) 6. CSRF & XSS (most ignored attack vectors) 7. TLS / Encryption (data in transit) 8. Secrets management (never hardcode) 9. API key lifecycle (rotate, scope, revoke) 10. Zero Trust (never trust internal traffic) Most systems fail not because of missing features but because of weak security fundamentals

Best Backend Projects That Get You Hired (2026) Distributed Rate Limiter (Redis + sliding window) Scalable URL Shortener (base62 + DB sharding) Distributed Job Queue (workers + retry + DLQ) Webhook Delivery System (retry, idempotency, signatures) API Gateway (auth, routing, rate limiting) Multi-tenant SaaS Backend (tenant isolation, billing logic) Feature Flag Service (dynamic config rollout) Distributed Lock Service (Redis/Zookeeper style) Session Store (distributed, TTL-based) Search Service (ElasticSearch + indexing pipeline) Log Aggregation System (ingestion + storage + query) Metrics Backend (time-series DB + dashboards API) Event Ingestion Pipeline (Kafka + consumers) ETL Pipeline (batch + streaming) Recommendation Engine Backend (ranking + retrieval) Fraud Detection Backend (rules + event processing) Chat Backend (WebSockets + persistence) Notification System (email/SMS/push + queues) Presence System (online/offline tracking) Activity Feed Backend (fan-out, fan-in models) Real-time Analytics Backend (stream processing) Distributed Cron Scheduler (job scheduling at scale) Workflow Engine (task orchestration, retries) Circuit Breaker Service (failure handling) Service Discovery Backend (dynamic service registry) Config Management Service (central config store) File Storage Backend (S3-like, signed URLs) CDN-like Backend (caching + edge logic simulation) Video Processing Backend (upload → transcode → serve) Image Processing Pipeline (resize, compress, store) RAG Backend (document ingestion + retrieval + LLM) Vector Search Backend (embeddings + similarity search) AI API Gateway (model routing + fallback) Prompt Logging & Evaluation Backend Semantic Search Engine Backend

Step-1: Learn Go Step-2: Learn goroutines, channel & ascheduler Step-3: Master pointers, interfaces & malloc Step-4: Build an HTTP server with std lib Step-5: Read the Go runtime & standard library source. Embrace humility Step-6: Build a production-grade backend (REST/gRPC, DB, caching, msging) Step-7: Make it resilient under load Step-8: Learn profiling and optimization (pprof, trace, benchmarks) Step-9: deploy with Docker & K8s Step-10: Ship it

@MaanasSehgal16 congrats , i also reached 100 users got the same feeling for contributing more

Reached a 10k+ strong community at CF Lite! Thanks a lot to each one of you 🙌 It’s an amazing feeling knowing that what you built is impacting so many users. Whether it’s through CF Lite or my work at TLE, I love contributing and will keep doing so 💪

Yay Finally crossed 100 users, Thank You!

@Monil0808 which resources u are following ?

Learning backend in depth Day 2: - learnt about event loop - timers , promises, ticks and phases

jaldi ka kaam shaitan ka

any hint? @AdarshRai525125

B not able to solve