Pick a system. Build it from scratch. Every lesson is choose → write → run, until it clicks.
80+ build-from-scratch courses · 9 languages · no credit card
Follow a career path
Sequenced courses that take you from zero to job-ready.
Backend Engineer
intermediate~80h
The infrastructure under every web service — Go, SQL, caches, queues, and the protocols that connect them.
Go FundamentalsSQL FundamentalsBuild Redis+5 more
Frontend Engineer
intermediate~65h
Master the browser end of the wire — JavaScript, TypeScript, then build the framework you depend on every day.
JavaScript FundamentalsTypeScript FundamentalsJavaScript Advanced+4 more
Full-Stack Developer
intermediate~90h
Both ends of the wire: TypeScript on the client, plus a backend language and the protocols that connect them.
JavaScript FundamentalsTypeScript FundamentalsSQL Fundamentals+4 more
DevOps / SRE
intermediate~70h
Run the systems other engineers build — Bash and Go for tooling; Docker, CI, and observability for the platform.
Bash FundamentalsGo FundamentalsBuild Docker+4 more
Data Scientist
beginner~60h
Python, R, and SQL — the canonical trio of data analysis. Plus the data structures behind efficient queries.
Python FundamentalsPython in PracticeR Fundamentals+4 more
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Each card opens a structured Fundamentals → Intermediate → Advanced track. Tap the > chevron to reveal all 37 languages.
“You can’t cheat — you either solve the problem or you don’t. It’s the first platform where I actually understand what I’m writing.”
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