CodingNeed.

JavaScript developer

Move from your first function to predictable service behavior and a tested HTTP API.

Your goal

Build the Expense API, reproduce a duplicate request, and explain which parts require durable storage.

Use each checkpoint as evidence: solve an exercise without the solution open, explain its edge cases, and revisit a failed concept the next day. Course completion records practice; it is not an accredited qualification.

STAGE 1 · Beginner

JavaScript from zero

From your first instruction to a working expense summary. No setup or previous coding needed.

11 lessons · 99 minutes of guided material, plus project and revision time.

Open syllabus →
STAGE 2 · Intermediate

JavaScript: dependable data and services

Bridge fundamentals and advanced systems with aggregation, search, retry budgets and idempotent events.

4 lessons · 115 minutes of guided material, plus project and revision time.

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STAGE 3 · Advanced

JavaScript engineering patterns

Build a cache, order dependent jobs, retain async outcomes and reason about sliding windows.

4 lessons · 115 minutes of guided material, plus project and revision time.

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Final review

  • Demonstrate a working example and a deliberately failing case.
  • Explain one design trade-off and the expected time and memory costs.
  • State which checks ran automatically and which required manual review.
  • Keep a short project README with setup steps, limitations and your next improvement.
Open project or practice lab →

Open your personal study plan to review weak concepts and schedule the next session.

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