Invite-only beta · High-level system design
High-level system design practice
that pushes back.
FabInterview runs a full HLD interview practice round: a real system design problem, an AI interviewer that questions your trade-offs, and a scored debrief when you put the marker down.
What you get
A full interview loop, not a chatbot with a prompt.
Interviewer
Follow-ups that probe
The AI challenges your choices the way a senior engineer would: capacity estimates, failure modes, trade-offs you glossed over.
Input
Speak or type
Talk through your design out loud with voice input, or type when you'd rather think quietly. Both work mid-session.
Library
Real problems
URL shorteners, rate limiters, news feeds. A curated set of high-level design questions across three difficulty levels.
Pressure
No hand-holding
The interviewer hands you the marker and stays quiet. No hints, no scaffolding, exactly like the round you're preparing for.
Debrief
Scored feedback
Every session ends with scores across requirements coverage, design quality, depth of reasoning, and communication.
Tracking
Progress over time
Session history and analytics show which dimensions are improving and exactly what to drill before the real loop.
How it works
Problem to debrief in one sitting.
1.
Pick a problem
Choose a question from the library and open the whiteboard.
2.
Defend your design
The interviewer clarifies requirements with you, then pushes on every decision while you sketch.
3.
Read your debrief
Scores, strengths, and the specific gaps to close before you sit the real round.
Private beta
Free for invited members.
We’re opening the practice room in small batches. Invited members get the full experience, up to 2 interviews a day, with a scored debrief after every round.
- Price
- Free
- Interviews
- 2 a day
- Scored debrief
- Included
Invite-only beta · Access in small batches