What is Test-Driven Development? — UK Software Development Guide

4 min readJune 2025ClickMasters Technical TeamReviewed by James Whitmore, CTO
what is test driven development

Direct Answer

Test-Driven Development (TDD) is a software development practice where tests are written before the production code. The TDD cycle is: Red (write a failing test), Green (write the minimum code to make the test pass), Refactor (improve the code while keeping tests passing). TDD produces high test coverage by definition, because every feature starts with a test.

Tdd in the UK

TDD improves software quality in ways that are relevant to UK compliance. High test coverage (a natural outcome of TDD) directly supports: Cyber Essentials secure configuration (tests catch configuration errors), DTAC Domain 3 for HealthTech (high test coverage is evidence of secure development practice), and FCA operational resilience (regression test suites prevent silent failures after changes). ClickMasters uses TDD for security-critical components and complex business logic — where the investment in writing tests first most clearly prevents production incidents.

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