Reddit Software Engineer Interview Questions
The questions to prepare for a Reddit Software Engineer interview. Questions from real interview reports rank first. Updated daily.
Use BFS over community-follower links to return all communities connected through shared followers.
RedditDesign a ledger that supports deposits, withdrawals, transfers, and balance queries efficiently.
RedditDesign Reddit's personalized homepage feed with retrieval, ranking, re-ranking, and online evaluation at scale.
RedditDesign a Reddit crawler that ingests user-submitted links, crawls domains, stores pages, discovers new links, and notifies users on completion.
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Design a low-latency ad event pipeline processing up to 900K events/sec with accurate click and impression aggregates for reporting and billing.
RedditExplain how you collaborate with product managers and data scientists to align goals, manage trade-offs, and deliver AI work effectively.
RedditEvaluates your resilience thinking and incident response approach.
RedditCompute daily active users and a 7-day rolling average using a CTE, distinct counts, and window functions.
Meta
Spotify
Meta ITUse CTEs, joins, and date filtering to calculate 30-day retention by signup cohort from login and feature usage data.
Curefit
Indeed
TikTokCalculate acquisition-cohort retention within 30 days by channel using CTEs, joins, and conditional date ranges.
EvenUp
PlayStation
AffirmAssesses web security understanding and defenses against CSRF attacks.
Reddit