Worked on the green-ecolution-backend repository to enhance authentication reliability by developing comprehensive tests for the login handler. Focused on backend development using Go, the work introduced mock services to simulate successful login scenarios and validate both HTTP responses and service interactions. This approach ensured that the login flow behaved as expected and reduced the risk of authentication regressions. Emphasizing API testing and unit testing, the implementation improved test coverage and maintainability of the authentication components. These targeted tests also accelerated continuous integration feedback, supporting faster and safer authentication changes while maintaining robust backend quality throughout the development process.