I'd stopped reviewing the basics, so I built a small site to practice them

epaso, a free site to practice for software interviews, in English and Spanish. "Repaso" means review in Spanish, which is all this is 📚 It has 897 questions across 17 topics. You don't need an account and there are no ads. You open it and the first question is already there 🚀 https://repaso.babylonace.dev/ Progress uses five boxes, Leitner style.

A right answer moves a question up one box. A miss sends it back to box 1. Wait times per box: same day, 1, 3, 7 and 16 days. Misses come back the same day for you to review.

"I don't know" is its own answer. You see the explanation and it doesn't count as a miss 🙌 There's also a random mode, a misses-only mode and a timed exam (30, 60 or 90 seconds per question) ⏱️ Your progress is saved in your browser, and the site works offline after the first visit thanks to a service worker. You can sign in with Google or GitHub to use it on another device, but nothing depends on that, and nothing is sent anywhere unless you sign in. A test checks that ✅ There's also a strict Content-Security-Policy, and no third-party scripts, fonts or styles.

I built it with Claude Code, then ran a separate review pass. I still use Claude Code every day to look for things to improve. The questions and explanations are AI-assisted too. It's plain HTML, CSS and JavaScript modules, no framework.

package.json has no dependencies at all; the browser tests use Playwright, installed separately. One small Node script builds the site and writes a static page for every question and topic, plus a sitemap, so search engines can read it without running any script. Deploys go through GitHub Actions only after the unit and browser tests pass. Each question has a stable id, and the Spanish version lives in a separate file matched by that id.

Another test makes sure a translation keeps every code span and the same line structure, so code never gets translated by accident. Figuring out what people want the second they land. For me that meant opening straight on a question, with nothing to set up first. Without that, it's easy to build something much more complicated than it needs to be.

The content is plain JSON under CC BY 4.0 and the code is MIT. If you spot something to improve, every question has a "Suggest a question or fix" link. And if an interviewer asked you something that isn't there, I'd love to add it 🎉 Code and content: https://github.com/babylonace/repaso