To Fix in Development: What It Is, Stages and How to Fix Bugs

What Does “To Fix” Mean in Development

To fix (to bugfix) — to correct an error in program code, configuration, or data. The term comes from the English “to fix” and is one of the most common words in a programmer’s vocabulary. A fix can be simple — correcting a typo in a single line — or complex, affecting the architecture of an entire module.

The verb “to fix” has a double meaning: besides fixing a bug, it can also mean “to commit changes in a version control system” (from English “commit/fix”). In both cases, the result is the same — the code becomes better than it was before. In the professional community, the distinction between the words is minimal, and both are used as complete synonyms.

The ability to properly fix bugs is one of the key developer skills. Errors are inevitable in any project, and the speed of fixing them directly affects product quality and user satisfaction. A systematic approach to fixes includes a clear process: reproduce, diagnose, write a test, fix, conduct a code review.

The Bug Lifecycle: From Detection to Fix

The bug lifecycle is a sequence of states that an error goes through from the moment of detection to complete elimination. Understanding this cycle helps organize the fix process and not miss critically important steps. In a typical process, a bug goes through five main stages.

Detection and Recording

The first stage is detection of a bug, which can happen through testing, error monitoring, user feedback, or automated crash reports. The bug is registered in a tracker with reproduction steps, environment details, expected and actual behavior. A good bug description is the foundation of a quick fix.

Reproduction and Diagnosis

The developer reproduces the bug in their environment, following the steps from the description. If the bug does not reproduce consistently, additional data is needed: logs, memory dumps, screen recordings. After reproduction, diagnosis begins — finding the root cause in the code. Debuggers, logging, and profiling tools are often used at this stage.

Writing a Test and Fixing

Before fixing, it is recommended to write a test that reproduces the bug — this guarantees that the fix actually works and prevents regression in the future. After the test fails with the expected error, the developer writes the fix code. The test should pass after the fix and be added to the regression suite.

func testLoginWithInvalidCredentials() {
    let result = AuthService().login(
        email: "wrong@test.com",
        password: "wrong"
    )
    XCTAssertEqual(result, .failure(.invalidCredentials))
}

Code Review and Verification

The fix is sent for code review — a colleague checks that the fix is correct, does not break related modules, and meets code standards. After review, the fix undergoes regression testing. In an ideal cycle, the bug is not considered closed until tests pass and the changes are approved by the reviewer.

Deployment and Verification

The fix enters the main branch and is deployed to production. After deployment, the team verifies the bug in the production environment and monitors metrics: whether the number of corresponding errors in crash reports has decreased. The bug is closed in the tracker with the version in which it was fixed.

Hotfix vs Bugfix: When and Which Approach to Choose

Hotfix is an urgent fix for a critical error that is currently affecting users in production. Such a fix is performed outside the regular development cycle: a separate branch is created from the release branch, minimal changes are made, the branch is tested and immediately deployed. After a hotfix, the changes are necessarily merged into the main development branch.

Bugfix is a planned fix that goes through the full lifecycle: from registration to code review and regression testing. A bugfix is part of a regular sprint and does not require emergency deployment. The difference between a hotfix and a bugfix lies in urgency and procedure, not in the complexity of the change itself.

When a Hotfix Is Needed

Hotfix is necessary when a problem blocking key functionality is discovered in production: the payment gateway is not working, authorization is failing, users see a blank screen. In such cases, every hour of downtime costs money and trust. A hotfix should be minimal — only a targeted change that eliminates the problem, without refactoring related code.

When a Bugfix Is Sufficient

Bugfix is suitable for non-critical errors: visual bugs, non-critical crashes on non-primary screens, inaccuracies in analytics data. Such fixes go through a full verification cycle and are included in the scheduled release. A planned bugfix helps avoid the regression that a hasty change could introduce.

A Practical Process: How to Properly Fix Bugs

A proper fix process is not just about writing code, but also a set of disciplines that make the fix safe and durable. Let us examine the sequence of steps to follow for each bugfix, regardless of its complexity.

Reproduce the Bug Locally

Before writing code, reproduce the bug in your development environment. Without reproduction, you cannot verify that the fix works. Use the same data as the user — copy the configuration, feature flags, API version. If the bug does not reproduce locally, add temporary logging to staging.

Write a Test That Fails Due to the Bug

A good practice is to first write a test that reproduces the bug and fails. This serves two purposes: first, you prove the bug exists, and second, after the fix the test passes, confirming the correction. The test remains in the codebase as protection against regression.

@Test
fun testCartTotalWithPromotion() {
    val cart = Cart().apply {
        addItem(Item("T-shirt", 29.99))
        addPromotion(Promotion("10OFF"))
    }
    Assert.assertEquals(26.99, cart.total())
}

Make a Minimal Fix

Minimal change is a key principle of bugfixing. Do not refactor neighboring code along the way, do not fix other bugs in the same commit. Each commit should solve exactly one problem. This simplifies code review, rollbacks when necessary, and understanding the change history. One change — one commit.

Verify the Fix Works and Does Not Break Other Parts

After writing the fix, run the full regression test suite. If the fix affects a shared module, also check the tests of related modules. Run the linter and verify that the code meets the project's standards. Only after this should you create a Pull Request.

Tracking Tools and Best Practices

Bug tracking systems are an integral part of the fix process. They help ensure no error is lost, assign responsibility, track status, and gather statistics. The choice of tool depends on team size and processes, but the basic functionality is similar: task creation, lifecycle, priorities, VCS integration.

Popular Tools

Jira is the most common system for enterprise projects, supporting flexible workflows, custom fields, and integration with Bitbucket/GitHub. GitHub Issues is a built-in tracker convenient for small and medium teams, integrated with Pull Requests. Linear is a modern tracker with a minimalist interface and high speed, popular in startups.

Best Practices for Fixes

First: fix the cause, not the symptom. If the app crashes due to a nil value, do not wrap the entire code in if let — understand why the value became nil. Second: a fix should include a test proving the correction. Third: do not fix two bugs in one commit — this complicates rollbacks. Fourth: add a link to the tracker issue in the commit description.

• Use the conventional commits format: fix(auth): handle nil token
• Always include a link to the issue in the commit description
• Verify that tests pass before and after the fix
• For hotfixes, create a separate branch from the release branch, not from develop
• Do not forget to merge the hotfix into develop after deployment