Building Operable Software with TDD (but not the way you think)

Explore a conference talk from NDC Porto 2024 where Martin Thwaites presents an alternative approach to Test-Driven Development for building operable software. Learn why traditional unit testing often falls short in microservice architectures and how "outside-in" testing that focuses on service boundaries can provide better deployment confidence. Discover how to implement "Contract First" TDD as a workflow to create more flexible tests that better define service boundaries. The presentation demonstrates using WebApplicationFactory in .NET as a scaffold and shows how to integrate with tracing tools like Honeycomb to visualize test performance and internal code interactions. Particularly valuable for developers working with microservices who currently rely on long-running integration tests in deployed environments but want a more efficient approach to building reliable, operable software.