Senior distributed systems engineer building Netflix's A/B testing and feature-flag infrastructure

This is a senior (L5, explicitly titled 'Senior Distributed Systems Engineer' in the JD) role on the Experience Foundation team within Netflix's Experimentation Platform, owning high-scale, low-latency services for experiment allocation and feature-flag evaluation on the critical path for product experiences across every device. You'll own reliability end-to-end (on-call, incident response, observability) and collaborate with teams using Flink, Spark, Elasticsearch, and Druid on experimentation data.

Practice this interview

Free · a live voice mock calibrated to this exact role

Start the mock interview

What this interview tests

High-scale, low-latency experiment allocation and feature-flag evaluation
Decentralized allocation and real-time rules evaluation architecture
Production ownership: on-call, incident response, observability (metrics/logs/traces)
Data/API contract design across pipelines (Flink, Spark, Elasticsearch, Druid)
Coding in Java or another JVM language
Cross-functional collaboration with product engineering and data science partners

Common question themes

Design a low-latency, decentralized feature-flag evaluation system

Lead me through an incident you owned on a critical-path service, and the follow-up reliability work

How do you define and enforce a data/API contract for consumers of experimentation data

A time you drove clarity and a decision out of an ambiguous cross-team ask

Coding in Java/JVM on a distributed-systems problem

How candidates describe it

Real Software Engineer (L5) - Experimentation Platform interview stories — retold from candidates' public write-ups, with sources.

Google · L5 Software EngineerNo offer

Google L5 software engineer interview: phone screening, three onsite rounds, system design, and a late rejection

A candidate interviewing for an L5 role went through a phone screening, three onsite coding rounds, a mobile system design round, and a Googleyness and Leadership round. Two of the four technical rounds went poorly by the candidate's own assessment, and after roughly two months of silence the recruiter reported that the role had been closed.

Interviewed January 2023 · Not specified

Google · L5 Software EngineerOffer

Google L5 software engineer interview: phone screen waived, vague onsite prompts, and an extra round before an offer

A senior software engineer with eight years of experience went through a Google L5 loop as part of a multi-company search that also produced offers from Bloomberg and Facebook. Google waived the phone screen and moved straight to a virtual onsite of three coding rounds, a system design round, and a Googlyness round; the panel then asked for two additional coding rounds and another system design round before the process concluded in an offer.

Interviewed 2021 · Not specified

Google · L3 Software EngineerOffer

Google L3 software engineer interview: phone screen, four coding rounds, and the Googleyness round

A candidate with two years of experience went from recruiter outreach to offer over about four months. The onsite was four 45-minute coding rounds — three of them featuring binary trees — and one round turned into a 25-minute chain of follow-ups about approximating an optimal solution at scale.

Interviewed June 2020 · Bangalore, IN

View the original posting

All Netflix Software Engineer interviews

All Netflix interviews