Launched this week
Prepd
Your Gym for Software Engineering Interviews
2 followers
Your Gym for Software Engineering Interviews
2 followers
Interactive system design and software engineering interview preparation platform with AI-driven mock interviews, structured exercises across HLD, LLD, and AI/ML tracks, real-time evaluation, skill analytics, and adaptive follow-up questions.
Free Options
Launch Team
Render Sandboxes: a computer for every agentGive every agent its own machine. Starts in under a second
Promoted
Hey Product Hunt 👋
I built Prepd because system design was the part of interviewing I was worst at, and every option was wrong for me. Books you read passively. Courses you watch. Human mocks at $100+/hr that you can't afford to do twenty times.
What was missing was reps. The thing that makes you better at system design isn't knowing what Kafka is, most people do. It's being forced to produce a whole answer under structure, repeatedly, until the shape becomes automatic.
So Prepd is drills. You pick a question, or paste one you were actually asked in a real loop, and work the phases an interviewer walks: requirements, estimation, API design, architecture, deep dive. You diagram in Excalidraw and the evaluation reads the diagram, not just your text, so a missing cache or load balancer gets caught even if you never wrote it down. There's a voice mode too, which matters more than I expected because people who write fluent answers often fall apart saying them out loud.
Three tracks: HLD, LLD, and AI/ML systems. That last one because ML system design is appearing in loops now and almost nothing covers it.
On pricing: 30-day passes, $10 to $60, one-time, no auto-renewal. You need a tool like this for about six weeks, not forever, and I didn't want revenue that depends on people forgetting to cancel. Free drills run without an account if you want to see the format first.
The evaluation is the hard part and the thing most likely to be wrong. If it grades you unfairly, tell me the specifics and I'll fix it. Happy to answer anything today.
Maker update: we've added a system design Learning path. Each concept is an animated diagram you step through, so you can watch what happens to requests as you go from one server to a load balancer, read replicas and a cache, and see what each change fixes and what it breaks. Every concept also has key points and interview Q&A. The first topic is free to read, no sign-up: https://prepd.tech/learning