Worked on stabilizing Engine API authentication for the NethermindEth/nethermind repository by addressing a critical issue with JWT secret path resolution. The solution involved removing a hardcoded default path and introducing logic to dynamically determine the correct JWT secret location based on the keystore directory. This approach improved reliability across different environments and deployments, reducing authentication failures and support overhead. The work was implemented using C# and leveraged skills in API development, backend development, and configuration management. By ensuring the Engine API consistently locates the correct JWT secret, the changes enhanced both operational stability and the security posture of the system.