tsconfig paths are a type-checker fiction, and Node has never heard of them

The piece says deployments fail silently until a dynamic import executes in staging ^[5], and it never explains why that construct is the tripwire. Worth naming, because it sets what a smoke test is actually worth. An alias specifier that tsc copied verbatim into the output ^[2] is inert text until something evaluates it. Specifiers in the entry graph are evaluated when the process boots, so a broken one is caught by anything that starts the app. A dynamic import sitting behind an admin route or an error handler is evaluated when someone reaches it, which can be a week after the deploy that broke it.

The article's own model is that the `paths` object is the canonical mapping and every other tool mirrors it ^[17], with TypeScript validating types, bundlers transforming imports for browsers, and Node resolving modules at runtime ^[16]. Its printed example shows how well hand-mirroring goes. The sample sets `baseUrl` to `"."` and three prefixes: `@/*` to `src/*`, `@components/*` to `src/components/*`, `@lib/*` to `src/lib/*` ^[9]. Elsewhere the same piece tells teams to standardize on one prefix mapped to a single source directory, precisely because ambiguous overlapping patterns break in bundlers with first-match semantics ^[8]. Since `@/*` already reaches `src/components`, the example ships two routes to the same files ^[14].

The runtime-loader option carries a cost the article states plainly and does not price: `tsx` and `ts-node/esm` avoid transforming files, but require consistent tooling across every environment ^[7]. That binds the choice to places you may not own, including CI images and base containers, and it means the resolution behaviour of your code is a property of how it was launched rather than of what was shipped.

One more line deserves a version check before you build on it. The article states that without `baseUrl`, TypeScript treats `paths` entries as invalid ^[10]. That is single-sourced, and the same post carries a disclosure that it was written with AI assistance under human supervision and review ^[11]. A guide whose worked example already contradicts its own guidance on overlapping prefixes ^[14] is a guide to read against your installed compiler and your installed bundler, not to copy.