NETFLIX · SYSTEM DESIGN

Netflix system design interview questions

Design comes up from mid-level and gets heavier at L5 and above. It is open-ended and often tied to the team's domain; senior candidates lead the discussion and work through build-vs-buy, operational and failure trade-offs.

From public candidate reports and Netflix's careers pages, checked November 2026. Processes vary by team. AlgoRung is not affiliated with Netflix.

Track my Netflix prep

Which levels get a design round

Level	Netflix title	Design round	Low-level design
SDE 1	L3 Software Engineer 3 (small new-grad program)	Usually not	–
SDE 2	L4 Software Engineer 4	Yes	–
Senior Software Engineer (SDE 3)	L5 Senior Software Engineer	Yes	–
Staff Software Engineer	L6 Staff, L7 Principal	Yes	–

Design questions candidates report

Ad frequency capping service

How to count ad clicks for billing and live dashboards at fifty thousand clicks a second: a redirect path that never loses a click, signed impression IDs for deduplication and fraud checks, per-ad per-minute stream aggregation with event time and watermarks, exactly-once sinks, salted keys for hot ads, an OLAP store for advertiser queries, and a nightly reconciliation that billing trusts.
Full walkthrough: Ad click aggregator

Also reported

Recommendation system and its signals
Forgot-password flow end to end
Distributed key-value store

How to answer any design question: the LADDER method · How the design round is scored by level

Questions people ask

When does Netflix ask system design?

A design round is part of the loop for SDE 2 (L4 Software Engineer 4), Senior Software Engineer (SDE 3) (L5 Senior Software Engineer), Staff Software Engineer (L6 Staff, L7 Principal). Design comes up from mid-level and gets heavier at L5 and above. It is open-ended and often tied to the team's domain; senior candidates lead the discussion and work through build-vs-buy, operational and failure trade-offs.

What system design questions does Netflix ask?

Candidates report: Ad frequency capping service; Recommendation system and its signals; Forgot-password flow end to end; Distributed key-value store.

System design questions at other companies

System design questions across all companies · Behavioral questions