JSON API design - Day 5/60 60 Day Go Backend Engineering Challenge

Description

"Day 5 of the 60 Day Go Backend Engineering Challenge. Today covers json api design with a focus on making json api design feel like request flow design rather than just handler boilerplate. Topics: - name the request boundary, validation step, and response contract before writing handler code - keep routing and middleware explicit enough that ownership of each concern is obvious - make serialization and status codes follow the service contract rather than handler convenience"