Bjorn Tore Gjerde focused on improving API correctness and reliability in the Altinn/altinn-storage repository, addressing a critical issue in the InstancesController Post method. He reworked the logic to source the appId from the query parameter, ensuring robust input validation by updating GetApplicationOrErrorAsync to throw errors when appId is null or whitespace. Using C# and leveraging his skills in API and backend development, Bjorn also refined unit tests to submit only required data, reducing brittleness and enhancing test resilience. His work contributed to more reliable instance creation flows and aligned with the repository’s goals for improved stability and error handling.