I rebuilt my interview prep repo from scratch. It's called isobath now.
Last year I posted a few times about the Frontend Master Prep Series: 650+ questions, then v2, then v3. The numbers kept going up. The depth did not. A lot of answers were correct but shallow. They told you what happen
Last year I posted a few times about the Frontend Master Prep Series: 650+ questions, then v2, then v3.
The numbers kept going up. The depth did not.
A lot of answers were correct but shallow. They told you what happens, not why. That is exactly the part interviewers push on.
So I stopped adding to it and started over. The new version is called isobath.
Live: learn.sachinmaurya.com
Source: GitHub
What changed
Every question now has the same shape:
- 30-second answer: what you would say first in the room
- Full answer: the mechanism, one runnable example, the pitfalls, likely follow-ups
- Deep dive: spec and engine level, edge cases, trade-offs
- Exercises: predict-the-output and fix-the-bug
Questions are ordered, so a topic reads like a book instead of a random list.
How it is written
- One Markdown file per question. Easy to review, easy to fix with a PR.
- Every answer is researched against primary sources: the ECMAScript spec, MDN, engine blogs, official docs. They are listed on each question.
- Code examples are actually run. When behaviour depends on the browser or the Node version, the text says which one.
- Nothing is marked "reviewed" until I have gone through it myself. Right now everything is labelled Draft, and the site says so.
What is live
- JavaScript: 183 questions
- TypeScript: 63
- HTML and CSS: 61
- Browser runtime: 51
That is 358 questions and about 3,800 flashcards. React is written and goes live next.
There are also study paths (frontend, backend, full-stack), a practice mode, search, and flashcards with spaced repetition. Progress stays in your browser. No account, no paywall.
Why the name
An isobath is a line on a map that joins points of equal depth. The site is about going one level deeper than the usual answer, so it fit.
What's next
Next.js, then Node.js and the backend topics. The full list is on the roadmap page.
Help me make it better
isobath is open source. Every question is one Markdown file, so contributing is an ordinary pull request.
The easiest ways to help:
- Spot a wrong or unclear answer? Open a correction issue. A one-line report is enough.
- Something out of date? The same page has an "outdated" template.
- Know a topic well? Pick a question that is still planned and write it. The writing guide explains the format and the sources to use.
The bar is the same for everyone, including me: primary sources, examples that were actually run, and versions named when behaviour depends on them. I review every question before it is marked as reviewed. Questions and flashcards are CC BY-NC-SA 4.0, code is MIT.
If you are preparing for interviews, try one topic and tell me where an answer is unclear or wrong.
Originally published by Dev.to WebDev. Aggregated on AIWithGhost for educational purposes — full credit and traffic to the original publisher.