Production Node.js and TypeScript Foundations

Predict execution order for Node.js code that combines timers, I/O callbacks, promises, and microtasks.

Coordinate and cancel concurrent asynchronous operations using Promise combinators and AbortSignal.

Implement a typed configuration layer that validates environment variables at startup.

Design a TypeScript module boundary that separates transport, application, and infrastructure concerns.

Implement centralized error propagation without losing stack traces or diagnostic context.

Process a large data source with Node.js streams while respecting backpressure.

Implement graceful startup and shutdown for a Node.js HTTP service.

Identify an event-loop bottleneck with Node.js profiling tools and choose an appropriate remedy.