Blog
Practical guides on the topics the arenas test — algorithms, languages, concurrency and security. Written by engineers, not generated filler.
Big-O Notation: A Practical Guide for Coding Interviews
A no-nonsense walk through the complexities that actually matter in interviews — O(1) to O(2^n) — with real examples and the traps to avoid.
How the JavaScript Event Loop Actually Works
Call stack, task queue, microtasks and async/await — the four moving parts that decide execution order in JavaScript, explained with a runnable example.
Python Generators and Lazy Evaluation, Explained
What yield actually does, why generators use constant memory, and when lazy evaluation turns a slow, memory-hungry loop into something elegant.
RAII and Move Semantics: The Heart of Modern C++
Why C++ doesn't need a garbage collector, how smart pointers own resources, and what std::move really does (spoiler: it doesn't move anything).
The OWASP Top 10 in Plain English
Injection, broken auth, XSS, SSRF and the rest — the most common web vulnerabilities explained without the vendor jargon, plus how to defend each.
Goroutines and Channels: Go's Concurrency Model
Why goroutines aren't threads, how channels communicate by sharing instead of sharing by communicating, and how select builds non-blocking logic.
How Elo Rating Works (and Why Code Royale Uses It)
The math behind Elo, what the K-factor controls, and why a zero-sum rating system makes every Code Royale battle meaningful.