Backend and infrastructure prompts that test requirements, data modeling, capacity, failure behavior, and cost. Each page is a structured exercise with a visible rubric.
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.