SYNTACTICAL
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syntactical
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High-velocity drills for developers who know all the answers
Step 1 / Select language
Frontend
JavaScript
1
Coercion, scope, and the runtime behavior that surprises.
Frontend Security
2
XSS sinks, sanitizers, and what the browser does and does not block.
TypeScript
3
Types, narrowing, generics, and what survives at runtime.
TypeScript Types
4
Type-level TypeScript: conditional, mapped, and template types.
Backend
Python
Runtime semantics, stdlib, and the sharp edges.
Go
Slices, interfaces, goroutines, and the zero values in between.
Ruby
Blocks, objects, and the dynamic behavior underneath.
Backend Security
Injection, broken auth, and the server-side bugs that leak data.
Rails
ActiveRecord, conventions, and what the framework does for you.
Node.js
The runtime: event loop, streams, buffers, fs, and modules.
Database
Postgres
Query planning, concurrency, and storage internals.
SQL
Portable queries: joins, grouping, NULLs, and windows.