Poor git practices create major headaches for development teams. Vague commit messages like "fix stuff" or "updates" make it impossible to understand what changed and why, especially when debugging issues months later.

The solution starts with adopting conventional commit standards:

• feat: add user authentication
• fix: resolve login validation error
• docs: update API documentation

For maintaining clean history:

• Use feature branches for all changes
• Rebase instead of merge when possible to keep linear history
• Squash related commits before merging to main
• Use tools like Husky to enforce commit standards automatically

A well-maintained git history becomes your project's documentation - you can quickly trace when features were added, bugs were introduced, and understand the reasoning behind changes.

Spaghetti React components are often the result of mixing too many concerns in a single component. A common mistake is creating components that handle data fetching, business logic, UI state, and rendering all in one place.

The key is separation of concerns:

• Extract custom hooks for data fetching and complex logic
• Use smaller, focused components instead of monolithic ones
• Follow the single responsibility principle

Example refactor:

Instead of a 200-line UserProfile component that fetches data, handles form validation, and renders everything, break it into:

• UserProfileContainer - data logic
• UserProfileForm - form handling
• UserProfileDisplay - presentation

This makes components easier to test, reuse, and debug. Consider using patterns like compound components for complex UI elements and render props or custom hooks for sharing stateful logic between components.

Inconsistent naming and file structure becomes a major productivity killer as projects grow. Establish clear conventions early:

Naming Conventions:

• kebab-case for file names: user-profile.tsx
• PascalCase for component names: UserProfile
• camelCase for variables and functions: getUserData

File Organization:

Group by feature rather than file type. Instead of separate components, hooks, and utils folders, create feature folders:

• auth/
• dashboard/
• user-management/

Within each feature, use subfolders like components/, hooks/, utils/, and types/.

Include index.ts files to create clean import paths:

import { UserProfile } from "@/features/user-management"

Document your conventions in a README and use ESLint rules to enforce them automatically.

Lack of reusable patterns leads to code duplication and inconsistent user experiences. Start by identifying common UI patterns in your designs and create a design system with reusable components.

Component Design:

Use composition over inheritance. Create base components with variants rather than separate components:

• ✅ Button variant="primary"
• ❌ PrimaryButton, SecondaryButton

Common Patterns to Standardize:

• Buttons, form inputs, modals, loading states
• Error handling and data fetching
• Form validation patterns

Custom Hooks Example:

Create a useAsyncOperation hook that handles loading states, errors, and success states consistently across your app.

Shared Utilities:

Establish utility functions for common operations like date formatting, API calls, and validation.

Document these patterns in Storybook or a style guide so team members know what's available. This approach reduces code duplication and ensures consistent behavior and styling across your application.

Testing frontend applications can feel overwhelming, especially when starting out. The key is to focus on testing behavior, not implementation details.

Start with React Testing Library:

This encourages testing how users interact with your components rather than internal state. Write tests that:

• Render a component
• Simulate user interactions (clicking buttons, filling forms)
• Assert on what the user would see

Example approach:

Test that clicking a "Submit" button shows a loading spinner and then displays a success message, rather than testing that a specific state variable changed.

Testing Pyramid Strategy:

• Lots of unit tests - for utility functions and custom hooks
• Some integration tests - for component interactions
• Few end-to-end tests - for critical user flows

Best Practices:

• Mock external dependencies like API calls to make tests fast and reliable
• Start with testing the happy path, then add error cases
• Use Vitest for fast test running
• Use Testing Library queries like getByRole() and getByLabelText() for accessible, maintainable tests

Poor onboarding wastes weeks of productivity and frustrates new team members. Create comprehensive but focused documentation to streamline the process.

Essential Documentation:

• README with clear setup instructions - Node.js version, environment variables, database setup
• Troubleshooting sections for common setup issues
• Coding standards and git workflow guidelines
• Project architecture decisions and patterns used

Operational Runbooks:

• How to deploy features
• Running and writing tests
• Debugging common issues

For QA Engineers specifically:

• Testing environment access and setup
• How to access staging servers
• Where to find test data
• Bug reporting and tracking procedures

Eliminate Environment Issues:

Use tools like Docker or development containers to eliminate "works on my machine" problems.

Support Systems:

• Video walkthroughs of complex setup processes
• Buddy system pairing new joiners with experienced team members
• First-week checklists covering environment setup, codebase understanding, and first feature completion

Good onboarding documentation serves as both a guide for new people and a reference for existing team members.