ESLint and Prettier are configured

Without ESLint and Prettier, code style diverges with every commit. Reviewers spend time on formatting comments instead of logic. Style inconsistencies accumulate until they generate real merge conflicts. ISO 25010 maintainability.analysability and modifiability both degrade as the codebase becomes harder to read and predict. Projects bootstrapped with create-next-app get a default ESLint config that is never customized — it provides minimal coverage and gives a false impression that linting is configured.

Install and configure both tools:

npm install -D eslint prettier eslint-config-prettier
npx eslint --init
echo '{}' > .prettierrc

For Next.js, extend the built-in config and add the Prettier integration:

// .eslintrc.json
{
  "extends": ["next/core-web-vitals", "prettier"]
}

Add lint and format scripts to package.json. Pair with git pre-commit hooks (see the git-hooks check) so neither tool is optional.