Tech Excellence meetup Daniel Moka Software Craftsman 🌐www.danielmoka.com How to convince the management and your colleagues to apply Test-Driven Development

www.danielmoka.com Daniel Moka - Software Craftsman Agenda Introduction Selling TDD to the management Convincing your colleagues to apply TDD Q/A

www.danielmoka.com Daniel Moka - Software Craftsman Introduction Software Craftsman from 󰏘 Wide spectrum of domain TDD advocate Helping teams to produce quality software

www.danielmoka.com Daniel Moka - Software Craftsman Why? TDD is still not widely adopted Highly misunderstood topic Pushback

www.danielmoka.com Daniel Moka - Software Craftsman What is TDD?

www.danielmoka.com Daniel Moka - Software Craftsman What do Management want? Fast and stable releases At lower costs With more satisfied end-users Bugless and working software

www.danielmoka.com Daniel Moka - Software Craftsman What TDD offers TDD reduces the number of defects High reputation Reduced costs

www.danielmoka.com Daniel Moka - Software Craftsman Finding bugs early is cheap If you catch a bug while coding it will cost you 80$. If you catch a bug with your CI pipeline it will cost you 240$. If you catch a bug with your Q&A process it will cost you 960$. If you catch a bug in production it will cost you 7600$

www.danielmoka.com Daniel Moka - Software Craftsman Relative cost of defects

www.danielmoka.com Daniel Moka - Software Craftsman What TDD offers TDD increases agility and productivity

www.danielmoka.com Daniel Moka - Software Craftsman What TDD offers TDD reduces cost by spending much less time on debugging

www.danielmoka.com Daniel Moka - Software Craftsman How to approach it? Requires cultural change Requires several technical skills Forcing never works Selling TDD to the management

www.danielmoka.com Daniel Moka - Software Craftsman TDD as a silver bullet Convincing your colleagues to apply TDD

www.danielmoka.com Daniel Moka - Software Craftsman Trust in our code Results in unique and meaningful tests Preventing false negatives Losing domain knowledge with TLD Seeing our test failing

www.danielmoka.com Daniel Moka - Software Craftsman What is code coverage and mutation testing? What is mutation score? - Killed mutants -> failing test - Surviving mutants -> passing tests - TDD produces high mutation score High quality of tests

www.danielmoka.com Daniel Moka - Software Craftsman TLD + code coverage + mutation testing - time consuming - very technical - demotivating (duct taping) - mandatory practices (while with TDD they’re optional) High quality of tests

www.danielmoka.com Daniel Moka - Software Craftsman - Great things with TDD - continuous refactoring - covering edge/corner cases - readable and meaningful tests - Keep testing and refactoring along the way - PRs won’t help Quality must be built in

www.danielmoka.com Daniel Moka - Software Craftsman Testability by design Improved UX Enforced refactoring TDD is a design technique

www.danielmoka.com Daniel Moka - Software Craftsman Minimizing Geek At Keyboard (GAK) activities Additional benefits #1

www.danielmoka.com Daniel Moka - Software Craftsman Reducing mental load and managing complexity Additional benefits #2

www.danielmoka.com Daniel Moka - Software Craftsman TDD is a joyful process Additional benefits #3

www.danielmoka.com Daniel Moka - Software Craftsman Seeing the tests fail is essential Trustworthy testsuite with high mutation score Built-in quality Powerful design technique Summing up

www.danielmoka.com Daniel Moka - Software Craftsman Thanks for attending! Twitter: @dmokafa Website: www.danielmoka.com Email: [email protected]

www.danielmoka.com Daniel Moka - Software Craftsman Questions?