Subjects

How to Tackle IELTS

A practical, resource-backed guide to preparing for IELTS Academic. Covers the best books, podcasts, and daily habits for each of the four skills — plus tested tips and tricks to maximise your band score.

System Design Basics

Learn the fundamental principles behind building large-scale, reliable systems: scalability, availability, latency, and the key trade-offs that drive real-world architecture decisions.

Concurrency vs Parallelism

Untangle four words engineers constantly confuse: concurrency, parallelism, threads, and processes. Learn what runs truly simultaneously versus what merely interleaves, why Python's async model is single-threaded, and how getting this wrong causes real production bugs like sharing one database session across coroutines.

Load Balancing

Understand how load balancers work, the algorithms they use (round-robin, least-connections, IP hash), Layer 4 vs Layer 7 differences, and how to design systems that stay healthy when servers fail.

Consistent Hashing

Understand the hash ring, virtual nodes, and why consistent hashing is the foundation of distributed caches (Redis Cluster, Memcached), distributed databases (Cassandra, DynamoDB), and CDN request routing.

The CAP Theorem

Understand why distributed systems can only guarantee two of Consistency, Availability, and Partition Tolerance — and how real-world databases (Cassandra, Zookeeper, DynamoDB, Postgres) navigate this fundamental constraint.

Database Indexing

Learn how B-tree and hash indexes work internally, how the query planner uses them, when to create composite and covering indexes, and how to diagnose slow queries using EXPLAIN ANALYZE.