Code RoomLLM inference serving
HardPrep Room Coding #3219

LLM inference serving

System designML systemsSenior–Staff~45 min

Design the online inference serving layer for a 70B-parameter LLM behind a public API. Traffic is bursty and request shapes vary wildly: some requests generate 10 tokens, some generate 4000, and prompt lengths range from 50 to 100k tokens. You must maximize expensive-GPU utilization while keeping interactive latency (time-to-first-token) acceptable. Design the request scheduler and batching strategy, explain why naive fixed-size batching fails here, and how you autoscale a fleet whose warmup takes minutes.

What a strong answer looks like

Clarify scale and constraints first. Propose a clean component breakdown, then go deep on the hard parts (data model, bottlenecks, consistency, failure modes) and name the trade-offs you are making.

Clarify5:00 left
Estimate5:00 planned
Design15:00 planned
Deep dive12:00 planned
Failure8:00 planned
0:00
Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.