DEVREPS

Core language mechanics — the fundamentals worth actually understanding, not memorizing.

The patterns that show up over and over — arrays, hash maps, trees, and how to recognize which one fits.

SOLID, composition over inheritance, and the patterns worth recognizing in real code.

ORM internals, request lifecycle, and the parts of the framework worth understanding, not just using.

The actual language of relational data — queries, joins, and the practical skills behind working with SQL day to day, not just the system-design trade-offs.

The tool every other domain in this app assumes you already know — commits, branches, and the actual mental model behind them, not just a list of commands to memorize.

Trade-offs at scale — caching, queues, consistency, and how real systems actually fail.

How real infrastructure scales: container deployments, serverless compute, queues and schedulers, presigned URLs, OIDC federation, and the entire class of gotchas that appear once you're managing real cloud resources.

Who is this user, what can they do, and whose data should they see? Authentication (proving identity), authorization (granting permissions), and multi-tenancy (safe isolation between customers). Hashing passwords, managing sessions, issuing tokens, and the gotchas that leak data across tenants.

How to wire a real product into a third-party messaging platform, using Meta's WhatsApp Business Platform as the concrete, working example — Business Manager, Meta for Developers, access tokens, templates, webhooks, and the trade-offs behind each design decision.

How real products safely move money: gateway integration, why the webhook is the source of truth (not the browser redirect), idempotency, and the double-entry ledger patterns behind every serious billing system.

Building a real, production LLM-powered feature: tool-calling architecture, the propose-then-confirm pattern for anything that writes data, authorization that never trusts the model, and the genuine bugs this kind of system produces.