Worked on improving authentication reliability in the tailscale/tailscale repository by addressing a bug in OIDC and OAuth 2.0 refresh token handling. Focused on backend development using Go, the work involved modifying the cmd/tsidp component to ensure empty refresh tokens were omitted from requests, aligning with protocol standards and reducing token-exchange errors. This targeted patch enhanced protocol compliance and improved interoperability with various identity providers, resulting in smoother login experiences for users. The approach emphasized low-risk, well-scoped changes that increased error resilience in authentication flows, demonstrating careful attention to standards and robust backend engineering practices within the Go ecosystem.