Skip to content

Tracks

AI-assisted engineering Working with AI Agents System design Core systems Data and AI systems Coding Coding problems Code review On-call SQL

Practice

Paths Concept guides

FreeAd-supported

The plan adds AI feedback and removes ads.

Concept guides/Databases in production/Query of death

CodingDatabases in production

Query of death

Hard3 min read

Questions it teaches

Postgres replica CPU spike from unoptimized queryMedium30 min Elasticsearch OOM from expensive aggregationHard40 min

Related

Databases in production Observability SQL Incident response Dependencies and deploys

Builds on: Observability

Cron failures (silent drops)3 min A/b variant regression4 min

Builds on: SQL

Duplicates5 min Joins5 min

Leads to: Incident response

A restore that stalls4 min CDN time-to-live (TTL)3 min

Related: Dependencies and deploys

Configuration errors3 min Environment misconfiguration3 min

© 2026 Prep Room·From California·AI can make mistakes.

About Legal Contact Cookies Your privacy choices

Home Review Tracks Paths