coding-standards

Use camelCase for files, directories, functions, and variables; PascalCase for types, interfaces, enums, and React components; UPPER_SNAKE_CASE for constants; and kebab-case for CSS classes. Document these rules in a shared conventions guide so reviewers can cite them.

Create custom error classes for domain errors, never swallow exceptions silently, and only use try/catch when you can actually recover. Throw specific errors like NotFoundError with resource and id context instead of returning null.

Prefer interfaces over type aliases for object shapes, and use discriminated unions for variant types like Result<T> with success and error branches. Avoid `any` and type assertions; use `unknown` with type guards instead.

Use Promise.all whenever async operations are independent, such as loading a user, orders, and notifications for a dashboard. Sequential awaits add latencies together, while parallel execution finishes in the time of the slowest call.

Common smells include functions over 30 lines, nesting deeper than 3 levels, magic numbers, duplicated logic, and god classes. Fix them by extracting smaller functions, using early returns, naming constants, and splitting classes by responsibility.