Test-Driven Development by Example, by Kent Beck. No other. Kent Beck doesn't even show up on the first page of Google anymore. The book is on page 6. But it's a human way to develop software, dealing with the human limits of the average programmer. The book is easier to read than most of the articles written about it.
Agile Manifesto, which many "agile" techniques often forget as well: https://agilemanifesto.org/principles.html
Test-Driven Development by Example, by Kent Beck. No other. Kent Beck doesn't even show up on the first page of Google anymore. The book is on page 6. But it's a human way to develop software, dealing with the human limits of the average programmer. The book is easier to read than most of the articles written about it.