Node.js & REST APIs

The route

1. Design resources and errors first

   URLs, status codes and error shapes, decided before a handler is written.

   You board here
   110 min
2. The request path

   Routing, middleware and validation, and which concern belongs where.

   110 min
3. Data, migrations and transactions

   Schema changes you can run on a Friday, and the transaction boundary that saves you.

   110 min
4. Auth without hand-waving

   Sessions versus tokens, hashing, and the parts you must never invent yourself.

   110 min
5. When it goes wrong at 2am

   Structured logs, metrics, timeouts, retries and idempotency.

   110 min
6. Deploying, and the first week after

   Config, health checks, and what is actually worth watching.

   110 min

A look at the teaching

// One shape for every failure, so a client needs one code path.
type ApiError = {
  error: { code: string; message: string; field?: string };
};

// 409, not 400: the request was valid, the world disagreed.
if (await orders.exists(courseId, userId)) {
  return json<ApiError>(
    { error: { code: "already_owned", message: "You already own this course." } },
    { status: 409 },
  );
}

Who is driving