Legacy Code Refactoring

18+

Years PHP

Since 2007

Refactoring Expertise

85%

Test Coverage Target

Systematic Code Improvement

Extract classes into focused, single-responsibility units
Apply proven design patterns to reduce complexity
Refactor code to be testable with dependency injection
Eliminate code duplication through shared abstractions
Use modern PHP 8 syntax and language features
Document architectural decisions and refactoring rationale
Legacy systems often contain God Objects where one class handles dozens of responsibilities, making them impossible to test or modify safely. Extracting focused classes following the Single Responsibility Principle transforms these monoliths into manageable, testable units. This refactoring pattern significantly reduces cognitive load, as developers no longer need to decipher thousands of lines within a single class. Well-factored code with clear boundaries leads to significantly fewer bugs in production.

Our Refactoring Process

Safe, Incremental, Production-Ready

Analysis & Safety First

Analyse codebase to understand existing patterns, identify pain points, and map dependencies. Write characterisation tests to capture existing behaviour and build approval tests for complex logic. Establish full understanding and regression safety before making changes.

Incremental Extraction

Extract small, focused classes from large files. Introduce interfaces and abstractions gradually. Each refactoring ships independently to production, maintaining continuous delivery whilst improving code structure.

Continuous Validation

Automated test suite validates every change. Static analysis tools catch regressions early. Peer review ensures quality and knowledge sharing across the team, building collective code ownership.

Business Impact of Clean Code

Measurable Improvements

Faster Feature Development

80% faster changes
Clean, well-structured code reduces the time needed to add new features. Developers spend less time deciphering legacy logic.

Fewer Production Bugs

10x deploy frequency
Testable code with clear boundaries reduces defect rates. Improved separation of concerns makes bugs easier to isolate and fix.

Easier Onboarding

2-week onboarding
New developers understand well-factored code faster. Clear abstractions and documented patterns reduce ramp-up time.

Reduced Technical Debt

50% debt reduction
Systematic refactoring pays down technical debt incrementally. Code quality metrics improve measurably over time.

Common Refactoring Patterns

Proven techniques we apply to legacy PHP codebases

Extract Class

Break large classes into focused units. Move related methods and properties into cohesive classes with single responsibilities.

Introduce Interface

Define contracts between components. Enable dependency inversion and make code testable through interface-based design.

Replace Conditionals

Transform complex if/switch statements into polymorphic class hierarchies. Use Strategy pattern for behaviour variation.

Repository Pattern

Isolate data access logic from business logic. Create clean boundaries for persistence concerns and enable easier testing.

Extract Service

Move business logic from controllers/models into dedicated service classes. Improve reusability and testability.

Value Objects

Replace primitive obsession with immutable value objects. Encapsulate validation and business rules within domain concepts.

Characterisation Tests

Capture existing behaviour in tests before refactoring. Build safety harness to prevent regressions during structural changes.

Incremental Delivery

Ship refactoring changes continuously to production. Avoid long-lived feature branches that become merge nightmares.

When to Refactor Legacy Code

Strategic refactoring timing for maximum impact

Ready to eliminate your technical debt?

Transform unmaintainable legacy code into a clean, modern codebase that your team can confidently build upon.