Primary-Language Buckets: Directory-Level Topic Cost Control
The repo uses a primary-language bucket pattern: split the entry points by language first, then list build-from-scratch project tutorials inside each bucket. The design turns topic selection into a bounded decision: choose a language, then pick a route within one consistent context, reducing switching and misfit cost. For beginners, it avoids framework-first wandering by anchoring learning to a deliverable project. For experienced engineers, it enables targeted gap-filling across stacks within the same language. The index stays lightweight while real training lives in your own implementation repo.
