Sprint Zero exists to eliminate day-1 risk: you don't get to the end of the build to discover that deploy doesn't work, the stack doesn't scale, or that security has a hole. In 1 week, the senior team sets up the repository in the client's GitHub, configures CI/CD pipeline to production, validates deploy of a static page, sets up authentication and secrets, writes 3-5 initial ADRs (stack, database, deploy, observability), and delivers prioritized backlog for the next 4 weeks. If something breaks in Sprint Zero, it's better to find out now — before scope becomes technical debt.
GLOSSARY
Sprint Zero
What is Sprint Zero?
Week of technical validation before the build. Stack, deploy, security, CI/CD and initial ADRs are defined in writing before any feature is coded.