WRITING
Notes on building and running systems
Engineering write-ups — architecture, security, and the occasional war story.
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01
Two Sum: from O(n²) brute force to a single hash-map pass
Two Sum is the first problem most people solve, and it's quietly a sales pitch for the hash map. Here's the brute force, the one trick that kills the nested loop, and the one-pass version I'd actually write.Jun 13, 2026 · 5 min read · #00001
02
Climbing Stairs: from exponential recursion to O(1) space
LeetCode 70 is Fibonacci in disguise. Here are the four solutions I actually reach for, why the naive one deserves to time out, and how to recognise the same shape in harder DP problems.Jun 13, 2026 · 6 min read · #00002
03
An encrypted handshake on top of TLS — and why I built one
Application-layer payload encryption for auth: ephemeral ECDH P-256 → HKDF → AES-256-GCM, with replay protection. What it buys you, and what it doesn't.Jun 5, 2026 · 2 min read
04
Two databases on purpose: Postgres and MongoDB, each where it fits
Polyglot persistence is a smell when it's accidental and a strength when it's deliberate. Here's the split I chose and the rule that keeps it sane.Jun 3, 2026 · 2 min read
Occasional notes on what I'm building
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