Spring Cleaning Your Codebase: A Practical Checklist

With spring 2026 just around the corner, it is a good time to turn that seasonal cleaning energy toward your codebase. Every project accumulates dead code, outdated dependencies, and small compromises that seemed reasonable at the time. Here is a practical checklist to help you cut through the clutter and start the next quarter with a codebase that is easier to work with.

Remove dead code

Dead code is the dust that settles in every project. Unused functions, commented-out blocks, feature flags that were never removed, and imports that no longer point to anything. It all adds up.

The problem with dead code is not just aesthetics. It creates confusion for anyone reading the codebase, adds noise to search results, and can even introduce subtle bugs when someone accidentally calls a function that was supposed to be retired.

Start by running your linter with strict unused-variable and unused-import rules enabled. If you are working in TypeScript, tools like knip ↗ can identify unused exports across your entire project. For a deeper look at automating code quality checks, we have a dedicated guide.

What to look for

• Functions or components that are never imported
• Feature flags for features that shipped months ago
• Commented-out code blocks (if it is in version control, you do not need the comment)
• Test utilities that no longer match the code they were written for
• Environment variables that are defined but never read

Update your dependencies

Outdated dependencies are one of the most common sources of security vulnerabilities and compatibility headaches. A quarterly dependency review keeps you ahead of breaking changes rather than scrambling to catch up.

Before updating anything, make sure your test suite is green. Then work through updates methodically:

Update type	Approach
Patch versions	Update in bulk, run tests, merge
Minor versions	Update one at a time, check changelogs for deprecations
Major versions	Treat as a separate task, read migration guides carefully

Pay special attention to dependencies that have been abandoned or archived. If a package has not had a commit in over a year, it is worth looking for an actively maintained alternative.

Tackle your TODO comments

Most codebases are littered with TODO comments that have been sitting there for months or even years. Search your project for TODO, FIXME, HACK, and XXX comments. For each one, make a decision:

• If it is still relevant, create a proper ticket for it
• If the code has been fixed or the concern no longer applies, delete the comment
• If it describes a genuine risk, fix it now while you are in cleanup mode

The goal is not to eliminate every TODO. It is to make sure the ones that remain are intentional and tracked.

Review your test suite

A healthy test suite is one that you trust. If your team regularly skips tests, ignores flaky failures, or works around slow tests, your suite is not doing its job.

During your cleanup, look for:

• Flaky tests: Tests that pass and fail without code changes erode confidence. Fix the root cause or remove them
• Slow tests: Identify the slowest tests and consider whether they can be optimised or moved to a separate CI stage
• Missing coverage: Check whether recently added features have adequate test coverage
• Skipped tests: Search for skip, xit, or xdescribe. If a test has been skipped for more than a sprint, either fix it or delete it

A test suite that runs quickly and fails meaningfully is worth more than one with impressive coverage numbers but constant false positives.

Clean up your configuration

Configuration files have a way of growing without anyone noticing. Over time, you end up with duplicated settings, environment variables for services you no longer use, and build configurations that have drifted from what you actually need.

Check these common trouble spots:

• Environment files: Remove variables for deprecated services. Make sure .env.example matches what the app actually needs
• CI/CD pipelines: Are you running steps that are no longer relevant? Are build caches configured correctly?
• Linter and formatter configs: Rules that are disabled across the board should either be re-enabled or removed entirely. ESLint ↗ flat config makes this a good time to modernise your setup if you have not already
• Docker files: Multi-stage builds that copy files you no longer need, or base images that are several versions behind

Standardise patterns across the codebase

As a project evolves, different developers introduce different patterns for the same problem. You might have three different approaches to error handling, two ways of fetching data, or inconsistent naming conventions across modules.

Pick the best pattern and standardise. You do not need to refactor everything in one go. Start by documenting the preferred approach and applying it to new code. Then chip away at the old patterns over time.

If your team uses TypeScript, type-safe patterns can help enforce consistency at the compiler level rather than relying on code review alone.

Audit your documentation

Code comments, README files, and internal docs all drift out of date. A quick audit can save future developers (including your future self) significant time.

Focus on:

• README: Does the setup guide actually work if you follow it from scratch?
• API documentation: Do the documented endpoints match what the code actually exposes?
• Architecture decision records: Are major decisions documented somewhere searchable?
• Onboarding docs: Could a new team member get the project running using only what is written down?

You do not need to write comprehensive documentation for everything. But the documentation you do have should be accurate.

Improve your developer tooling

While you are in cleanup mode, take a look at your local development setup. Small improvements here pay dividends every single day.

Consider whether your team would benefit from:

• Shared VS Code workspace settings for consistent formatting and linting
• Pre-commit hooks to catch issues before they reach CI
• A Makefile or task runner to standardise common commands
• Better error messages in your build scripts

Even AI coding assistants can help with cleanup tasks like identifying unused code, suggesting refactors, or generating missing tests.

Make it sustainable

The best cleanup is the one that does not need to happen because your team maintains quality continuously. After your spring clean, consider adopting a “boy scout rule”: leave the code a little better than you found it, every time you touch it.

Set aside a small portion of each sprint for maintenance work. Track your technical debt alongside feature work so it stays visible. And schedule your next cleanup before the current one fades from memory.

A clean codebase is not a luxury. It is the foundation that lets your team move quickly and ship with confidence.