JavaScript: dependable data and services
Bridge fundamentals and advanced systems with aggregation, search, retry budgets and idempotent events.
Prerequisite: JavaScript foundations · 115 minutes of guided study
4 published lessons, from first principles to a small project.
Start first lesson →What you’ll be able to do
- A repeated identifier must keep the same meaning.
How to study this course
Follow the numbered modules. Read the example, explain why it works, attempt the exercise, then compare your result with the supplied checks.
Setup: A modern browser. JavaScript, TypeScript, Python and SQLite exercises run here; project workshops state their additional setup.
Times estimate guided reading and practice. Projects and revision can take longer.
Course syllabus · 4 lessons
Bridge · From syntax to engineering
- Aggregate without mutating the input25 min · Browser exercise →
Separate reading data from changing your result.
- Find the first matching value with binary search25 min · Browser exercise →
Maintain a search interval whose boundaries have precise meanings.
- Plan bounded retries25 min · Browser exercise →
A retry policy needs both a delay limit and a total budget.
- Project · Apply each ledger event once40 min · Browser exercise →
A repeated identifier must keep the same meaning.