Design Google DocsSystem designMany people edit the same document at once and see each other's changes and cursors live, with offline edits and full version history.
Last asked Sep 2026
SpaceXAI system design interview
Round 5 of 7 · 8 questions reported
- Format
- Scope a vague prompt, then write working code for it
- They grade
- First-principles reasoning over memorized architectures
- Heads-up
- Not in every loop. The domain follows the team: infrastructure, networking, frontend or ML systems.
Questions SpaceXAI asks in this round 8
- Design TinyURLSystem designTurn long URLs into short links and redirect visitors fast, at billions of redirects a day, with optional custom aliases and expiry.Last asked Sep 2026
- Design a rate limiterSystem designDesign a service that limits how many requests each API client can make. It sits in front of every API endpoint at high traffic.Last asked Jan 2026
- How data collection shapes model performanceML designPick a project from your resume and explain how its data was collected and processed. Then discuss how data choices (coverage, label quality, noise, imbalance, distribution shift)…Last asked Sep 2026
- Design a notification systemSystem designA shared service other teams call to send push, email and SMS notifications: templates, user preferences, retries, deduplication and rate limits.Last asked Mar 2026
- Design a RAG system over company docsAI systemEmployees should be able to ask questions about internal documents (Drive, Confluence, Slack, GitHub) and get grounded answers with citations.Last asked Jan 2026
- Design a retrieval-augmented generation systemAI systemDesign a RAG system: users ask questions and an LLM answers using documents retrieved from your corpus. Cover ingestion and chunking, embeddings and the index, retrieval and…Possibly retired
- Design ChatGPTAI systemDesign a consumer chat product backed by a large language model: conversations, streamed replies, history across devices, at 100M weekly users.