TypeScript
TypeScript is the default language for product surfaces I ship: NestJS APIs, Next.js apps, and editor extensions. BidiMD is the clearest public example — VS Marketplace + Open VSX, RTL Markdown preview without patching the workbench. On the backend side I keep contracts thin and explicit (same idea as this site’s /v1 API). On the editor side I care about marketplace packaging, Open VSX parity, and lint false positives that waste maintainer time (Biome forwardRef note).