During November 2025, Mariusz Jasuwienas developed a data fetch optimization for the hiero-ledger/hiero-json-rpc-relay repository, focusing on improving API performance and scalability. He implemented a solution in TypeScript and Node.js that omits unnecessary transaction data parameters when fetching from the Mirror Node API, thereby reducing payload size and network load. This targeted approach addressed the specific requirements of ticket #4598 and resulted in faster response times for mirror node data retrieval. Mariusz maintained high code quality through clear documentation and traceable commits, demonstrating a focused engineering effort in API development and optimization within a short project timeframe.