Went through the Roblox DE loop in January 2026. There's almost nothing online specific to their data engineering interview so I'm writing this up.
The process (DE-specific): Recruiter screen (30 min, standard) Technical phone screen (60 min, mixed SQL + pipeline design) Onsite loop: SQL deep-dive, system design for data, behavioral, hiring manager
SQL round: The SQL was harder than I expected. Not just aggregations and joins. They gave me a scenario involving event-stream data from user sessions in a game. I had to write a query to calculate session durations, handle null end events (players crash or close the app), and find users with unusual patterns. Window functions were essential. They also asked me to optimize a slow query with a query plan walkthrough, which I hadn't seen at other companies at this stage.
Know: CTEs, window functions (LEAD, LAG, ROW_NUMBER), partition by, handling nulls in event data, writing queries that don't do full table scans on huge tables.
Pipeline design round: This was the most Roblox-specific part. They described a scenario: you need to build a pipeline that ingests real-time player activity events from millions of concurrent sessions, transforms them, and makes them available for both real-time dashboards and batch ML feature generation. Classic lambda vs. kappa architecture tradeoff.
They cared about: exactly-once semantics (or why you'd accept at-least-once), latency requirements for the real-time path, idempotency in the batch path, and how you'd handle schema evolution as the game events change.
Tools I mentioned: Kafka for ingest, Spark Structured Streaming for the real-time path, dbt for the batch layer. They mentioned they use Spark internally so that felt relevant.
Behavioral: Mostly focused on cross-team work and handling ambiguous requirements from analytics stakeholders. Same ownership themes as the SWE behavioral rounds.
Comp: I ended up with $195k base for a senior DE role, RSUs made it higher but I don't want to be specific. Felt slightly below what I've seen for senior SWE at the same level but DE band is what it is.