How to use this roadmap
- This complements, and deliberately doesn't repeat, the DSA and Concurrency roadmaps — pure algorithms and thread-coordination puzzles stay there. Everything here is about working inside real, imperfect code under real time pressure.
- Topics build roughly in the order a candidate encounters them across a loop, but each is self-contained — jump straight to the format you know is coming up.
- Reference implementations target Python, Java, and JavaScript — this roadmap's theory and exercises are otherwise language-agnostic by design.
- There's no single “LeetCode” equivalent for these formats — practice problems link out to refactoring katas, Exercism, and public practice APIs instead.
- This is an independent track in the interview prep collection: its own progress, its own “come back later” list, and no interview countdown.
The Roadmap
- 1
What a 'practical coding round' actually means in 2026, and how to survive being watched while you work.
- 2
The bug-squash round: reproduce, isolate, and fix a real bug in code you've never seen, on a clock.
- 3
The repository-based round: add a feature to code you didn't write, without becoming the next person who broke it.
- 4
Writing correct, useful tests fast enough that they save time in a live round instead of costing it.
- 5
Reading unfamiliar code like a reviewer, and changing it in steps small enough that a mistake is always cheap to undo.
- 6
Stripe calls it the 'Integration round': given docs and a goal, build something that actually talks to a real API and survives real-world responses.
- 7
You already know how to design a parking lot or a rate limiter. This topic is about actually finishing one, working, in 60-90 minutes.
- 8
The capstone topic: two people at one keyboard, defending code you wrote days ago, and — increasingly — an AI assistant sitting in as a third participant.