Software Engineer

The essential foundations every software engineer needs — algorithms, system design, clean code, testing, and career growth.

Computer Science Fundamentals

The mathematical and theoretical foundations that make you a better engineer regardless of language or framework.

Data Structures

Arrays, linked lists, stacks, queues, hash maps, trees, heaps, graphs — when to use each.

Algorithms

Sorting (merge, quick, heap), searching (binary), graph (BFS, DFS, Dijkstra), dynamic programming.

Time & Space Complexity

Big O notation, best/worst/average case, space complexity, trade-offs between time and memory.

Operating Systems

Processes vs threads, memory management, virtual memory, file systems, I/O, concurrency primitives.

Clean Code & Software Craftsmanship

Internal

Write code that humans can read, maintain, and extend — not just code that works.

SOLID Principles

Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, Dependency Inversion.

Design Patterns

GoF patterns: Singleton, Factory, Observer, Strategy, Decorator, Repository, Adapter.

Refactoring

Extract method/class, rename, move field — improve code structure without changing behaviour.

System Design

Internal

Design scalable, reliable systems — the skill that separates senior from junior engineers.

Scalability Fundamentals

Load balancing, horizontal scaling, stateless services, consistent hashing, CAP theorem.

Caching & Databases

Cache layers (CDN, app, DB), sharding, replication, SQL vs NoSQL decision framework.

System Design Interview

Framework: clarify → estimate → design → deep-dive. Classic problems: URL shortener, Twitter, WhatsApp.

Testing

Code without tests is broken by definition. Write tests that give you confidence to refactor.

Test-Driven Development (TDD)

Red → Green → Refactor cycle. Write the test first, make it pass, then clean up.

Unit & Integration Tests

Test in isolation vs test with dependencies. Mocking, test doubles, fakes, stubs.

Testing Pyramid

Many unit tests, fewer integration tests, few E2E tests — balance speed and confidence.

Version Control & Collaboration

Work effectively with a team using Git workflows, code reviews, and engineering norms.

Advanced Git

Rebase, cherry-pick, bisect, reflog, submodules, git hooks, interactive staging.

Code Review Best Practices

Give respectful, actionable feedback. What to look for: logic, readability, tests, security.

Technical Documentation

ADRs (Architectural Decision Records), README standards, inline comments when WHY is unclear.

Career Growth

Internal

Navigate levels, build reputation, and grow from junior to senior to staff engineer.

Junior → Senior Progression

What differentiates levels: scope, independence, mentorship, technical judgment.

Technical Interviews

LeetCode prep (patterns not memorisation), behavioural (STAR method), system design.

Building in Public

Blog, open source, Twitter/X, Discord — build reputation and network simultaneously.