camera, messaging, and augmented reality
Snap system design practice is one slice of a 50-prompt set. Narrate the user and the API before you draw boxes. Call out the bottleneck you are willing to leave for a later version. Design for a phone on a weak radio. If your answer needs a datacenter round trip for every tap, say why.
Practice these prompts with an AI interview copilot, or download Luna for Chrome, Mac, and Windows.
System design
Commonly reported
How to approach. Users and API first. For ephemeral media delivery, say the one request you must make fast and the one you can delay.
Practice this with LunaSystem design
Commonly reported
How to approach. Draw one failure domain and what still works. Snap interviewers listen for what you explicitly will not build yet.
Practice this with LunaSystem design
Commonly reported
How to approach. Put the capacity math on the board with units. Round numbers are fine if every assumption is labeled.
Practice this with LunaSystem design
Commonly reported
How to approach. Retries need an idempotency story. Say what the client sends the second time and what the user sees.
Practice this with LunaSystem design
Commonly reported
How to approach. Split the hot path from analytics. Name the log or queue in one sentence and move on.
Practice this with LunaSystem design
Commonly reported
How to approach. If a cache can be stale, say who notices and how the product tells the truth. Do not hide staleness.
Practice this with LunaSystem design
Commonly reported
How to approach. List readers, writers, and auditors before you pick a database. Authorization is part of the design, not a footer.
Practice this with LunaSystem design
Commonly reported
How to approach. Describe the migration in two phases and the rollback. A long freeze is a smell; say so.
Practice this with LunaSystem design
Commonly reported
How to approach. Name the load you shed first and the promise you keep. Tie that promise to Snapchat.
Practice this with LunaSystem design
Commonly reported
How to approach. Noisy-neighbor control is a product decision. Say the fairness unit — tenant, user, or key — and the limit.
Practice this with LunaThese passed review. The date is when the candidate submitted the report.
Tell us the company, the role, the round, and the question in your own words. Submissions stay pending until a reviewer approves them. Approved prompts can show a Reported by candidates badge. If you leave an email, we can match an affiliate reward — the program pays 30% commission.