A single index for every routeable design exercise. Canonical prompt pages live under the classic or ML system design tracks.
Enforce tenant and user quotas across API gateways without turning Redis into the only thing that matters.
Run delayed and recurring work with retries, backoff, leases, and a clean story for duplicate execution.
Protect a database from hot reads while staying honest about invalidation and stale data.
Generate short links, redirect at high read volume, and handle abuse without losing the simple core.
Move work between producers and consumers with leases, ordering boundaries, and backpressure.
Send email, push, and in-app notifications while respecting preferences, dedupe, and provider failures.
Keep a searchable index fresh while writes, deletes, and ranking signals arrive from different services.
Collect logs, metrics, and traces without making every outage an ingestion-cost problem.
Build retrieval, generation, citation, and evaluation loops that do not collapse into a demo prompt.
Serve models with versioning, autoscaling, canaries, and rollback paths that operators can trust.
Keep online and offline features aligned enough that model scores mean what training said they meant.
Run offline, online, and regression evaluations with lineage strong enough to stop bad releases.
Serve nearest-neighbor retrieval with filtering, index refresh, recall measurement, and cost controls.
Coordinate data, checkpoints, accelerators, and recovery for large training jobs.