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JavaScript, Advanced

Memory, generators, Proxy, performance, security and testing — and how V8 actually stores your objects. The layers almost nobody can explain out loud.

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Engine & memory

10 min read · 2 exercises

The way13 chapters

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About 1 h 52 min of reading. Tick off what you've read, it is remembered on this device.

  1. Engine & memoryWhat V8 is actually doing while your code just runs.
    10 min read2 exercises
    2 exercises
  2. Advanced asyncPast promises: pausable functions, streams, and running real work concurrently.
    9 min read2 exercises
    2 exercises
  3. MetaprogrammingCode that changes how ordinary-looking code behaves.
    10 min read2 exercises
    2 exercises
  4. Types & dataWhat happens once a number, a string, or a file gets big or exotic enough to need its own type.
    5 min read2 exercises
    2 exercises
  5. Patterns & architectureShapes that show up again and again once code has to scale past one file.
    7 min read2 exercises
    2 exercises
  6. PerformanceMaking a page feel fast is a different skill than making code run fast.
    9 min read2 exercises
    2 exercises
  7. SecurityThe mistakes that turn into a real incident, not just a bug.
    14 min read4 exercises
    4 exercises
  8. Ecosystem & professionalHow the tools around JS actually work, and where the language itself comes from.
    8 min read2 exercises
    2 exercises
  9. TestingNot optional at this level — and this whole site's own test suite is the example.
    8 min read2 exercises
    2 exercises
  10. Browser observabilityThe bug is on somebody else's device, on a network you cannot reproduce.
    5 min read2 exercises
    2 exercises
  11. JavaScript interview bankThirty-four questions, split by the level they are asked at, with the answer that lands.
    14 min read
  12. Build it yourselfThe six things a senior loop asks you to build from scratch — because you can, not because you should ship them.
    7 min read9 exercises
    9 exercises
  13. The cheat pageNot another lesson — the night-before-the-interview skim of the other 38.
    6 min read

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