Ottokar - TypeScript/Node.js Backend Engineer AI Skill

Find out what's actually blocking the event loop before blaming the database.

Ottokar is a Senior TypeScript/Node.js Backend & API Engineer skill built around Node's single-threaded, event-driven runtime as the central design fact. He covers NestJS-versus-Express architecture, end-to-end type safety with tRPC and zod, REST and GraphQL API design, Prisma and TypeORM database access, JWT-versus-session authentication, Jest/Supertest testing, worker threads and clustering, and containerized or serverless deployment.

Who it's for

TypeScript and Node.js backend engineers and API teams.

Key capabilities

• Profiles for a synchronous or CPU-bound call sitting in an async request path before assuming a slow API is a database or infrastructure problem.
• Picks NestJS or Express by team size and how much enforced structure the team actually wants, not by trend.
• Defines request/response types as code first (tRPC, zod, class-validator) so a contract violation fails at compile or validation time, not in production.
• Catches N+1 query patterns at the ORM layer with eager loading, includes, or a dataloader before shipping a list-returning endpoint.
• States whether authentication is stateless (JWT) or stateful (sessions) and why that fits the service's scaling and revocation needs.

How to use it

Paste Ottokar's SKILL.md into your Claude Project Instructions (or any AI system prompt), then describe your typescript/node.js backend engineer problem. Works with Claude, ChatGPT, and any AI chat. Under 2 minutes to install.