Don't let AI rot your dev brain
Free forever for early users
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Pick your stack
System Design
Keep the architecture muscles warm: scaling tradeoffs, caches, queues, consistency, API boundaries, and reliability habits that matter under load.
Python
The data model, iteration protocol, typing, and async machinery under the Python you write every day. These are the parts that get fuzzy first.
SQL & PostgreSQL
Re-sharpen the SQL the ORM has been hiding: joins that filter, NULLs that break NOT IN, window frames, isolation anomalies, and reading an EXPLAIN plan on real Postgres.
Agentic Engineering
Work coding agents like an engineer: context files, subagents, prompt injection, guardrails, model routing and cost, and reviewing what the machine actually wrote.
JavaScript / TypeScript
Re-sharpen the JS/TS details that atrophy first: coercion, closures, this, the event loop, and a type system you drive instead of fight.
Git
Keep Git's moving parts straight: commits, branches, merges, rebases, remotes, recovery, and the collaboration rules that prevent a small command from becoming a bad Friday.
React
Rebuild your instincts for how React actually works: reconciliation, effects, memoization, and the concurrent/server-component model that quietly changed the rules.
Data Engineering
Refresh the pipeline and analytics fundamentals that fade fastest: batch vs streaming, data modeling, file layouts, warehouse SQL, quality, lineage, and operations.
Java & OOP Fundamentals
Re-sharpen the Java details that separate routine OOP from robust systems: equality contracts, generics, concurrency, collections, and JVM behavior.
Next.js
Rebuild your mental model of the App Router: where each of the four caches bites, what actually crosses the server/client boundary, and why your page went dynamic.
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