About this app
Practice system design interviews by talking through them. Jobby is a voice-first mock interviewer. You speak your design out loud. It listens, asks follow-ups, challenges your tradeoffs, and scores you when you're done. 42 problems. Pick one and go. Covers every major pattern — URL shorteners to distributed databases. Each problem has a study guide so you can learn before you practice. Two modes. Practice mode walks you through it together. Interview mode doesn't help — it pushes back, probes assumptions, and stays quiet when you're stuck. Just like the real thing. Scored on 5 dimensions. Structure, clarity, tradeoff reasoning, handling pushback, and conciseness. Every session ends with a report card and specific feedback. Pause and resume anytime. Mid-interview and need to stop? Pick up exactly where you left off. 2 problems a day. Done in 3 weeks. Reading doesn't stick. Talking through designs does. That's the whole idea.
Latest release
What’s New
Improved UI and UX.
Audience growth
Ratings growth
Baseline captured. Growth appears after the crawler observes a changed rating count.
Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.
Price tracking
Price intelligence
First snapshot captured. The trend line starts after the next crawler price observation.
- First observed Sep 1, 2026 · 2:56 PM Free
Screenshots
