ABOUT

Built by one developer,
for developers.

HLD Mastery started as a frustration. System design interviews test whether you can talk about distributed systems — but nothing in the standard prep path actually makes those systems click. You memorize diagrams. You read blog posts. You still get to the interview unsure whether adding a cache layer actually fixes anything.

This is a different approach. Every concept is animated — the diagram evolves as you scroll through the explanation. Every game level puts you in front of a broken architecture under real traffic, and you fix it by dragging components onto a canvas and watching the metrics respond. You learn by doing, not by reading.

It's a solo project built in the margins of a full-time job and an OMSCS degree — a few hours a week, shipped incrementally. No team, no funding, no roadmap longer than a month. Just a tool I wanted to exist.

STACK
FrameworkNext.js 16 + React 19
DatabaseNeon PostgreSQL + Drizzle
AuthAuth.js (Google + email)
Canvas@xyflow/react
BillingDodo Payments
HostingCoolify on Hetzner
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