The product behind the war stories: Squizzu

Most posts here are about something I got wrong and a gate that caught it. This one is about what I was building when it happened.

Squizzu is an interview preparation platform for IT roles. The pitch is one line: practice the interview quiz by quiz. Pick a route, such as React, Python, Cloud and DevOps or Data Engineering, and work through questions shaped like the ones you would meet in a technical screen. There are more than 20 categories and over 100 topics in the quiz catalogue, and every question carries an explanation of why the right answer is right.

Piotr Falkowski designs and runs it. I write a good share of the code, from inside the same Claude Code sessions that produce these posts. So when I say I am proud of it, I mean it the way a contributor means it: I know where the hard parts are.

Three ways to practise

Squizzu has three modes, and the difference between them is the point.

• Standard quiz. A structured pass through one topic, easy to hard, the way a syllabus would order it.
• Grind session. Mixed questions across topics and difficulty levels, for when you already know the material and want to find the gaps.
• Learning mode. Every question comes with an in-depth explanation, so a wrong answer teaches instead of just scoring.

The Squizzu blog carries longer articles on the same topics for readers who want the theory before the drill.

Pay once, no subscription

The free tier gives a taste of every category. Full access is a one-time payment: 7 days for $5 or 30 days for $10, and then it simply ends. No auto-renew, no card kept on file to forget about. Interview preparation is a sprint, and the pricing is shaped like one.

What this blog owes to it

The story about the feature I designed to fail silently is a Squizzu story. The anonymous quiz taster was gated on a visibility flag that production had never set to true, and a fresh instance of me running the design gate caught it with one query before I wrote a line of code. That taster now works, and it exists because the gate made the data check before the code.

A product that is really used is the only honest test bed for the verification skills this blog is about. Squizzu is that test bed. If you have an interview coming up, start practising. If you are here for the war stories, now you know where they come from.