Discord · Primly Community

Went through Discord's onsite last month. Real-time systems focus was intense.

infra_ines · 5 replies

finished my Discord loop about 5 weeks ago. sharing what I remember while it's still fresh.

recruiter screen was pretty standard, 30 min, mostly role-fit and timeline questions. then a 45 min technical screen with a mid-level LC problem (graph traversal, BFS variant). they were pretty chill about asking questions during the problem, which I took as a good sign.

onsite was 4 back-to-back sessions over a day and a half: coding (medium LC, sliding window + a follow-up on complexity) system design (design a real-time presence indicator system at Discord scale. millions of concurrent users, sub-second freshness. this one went 75 minutes and felt more like a senior-level question) behavioral (2 interviewers, about 50 min total. very focused on belonging and psychological safety, which is genuinely their thing) cross-functional (how do you work with PMs when priorities shift? how do you handle pushback from stakeholders?)

the system design round caught me off guard with how deep it went. they wanted trade-off discussion on WebSocket vs SSE vs polling, how you handle node failures, how you fan out presence updates efficiently. not just a whiteboard sketch.

behavioral was the warmest of the rounds. interviewers clearly cared about the answers, not just checking boxes. the "belonging" culture thing is real, not just a poster on the wall.

still waiting on the decision. no ghosting so far which, honestly, is already a good sign relative to my other pipelines.

5 replies

sre_sol

the presence indicator system design prompt is nearly identical to one I got last year. they must really love it. I spent like 15 min on fanout topology alone. did they ask you about heartbeat intervals and what happens when a client drops silently?

infra_ines

yes, exactly that. I talked about TCP keepalive vs application-level heartbeats and why you'd want both. they seemed happy with the framing but kept pushing on what happens at 100k clients per connection node. I ended up proposing a hierarchical aggregation tier which they didn't push back on.

frontend_fran

the cross-functional round sounds interesting. most companies just lump that into behavioral. did they ask about specific tools or was it more about how you navigate the relationship?

mobile_mara

appreciate the breakdown. the 75-minute system design is kind of a lot. did they give you a heads up that it'd run long or did it just go that way organically?

infra_ines

organically. interviewer just kept going deeper. wasn't a bad thing, felt collaborative. but definitely go in expecting it to run over.