Marcin Ziolek developed advanced synchronization features for the hyperledger-labs/splice and splice-wallet-kernel repositories over a two-month period. He implemented multi-synchronizer support in LocalNet, enhancing distributed testing by updating Docker Compose configurations and integration tests using Scala and Docker. In splice-wallet-kernel, Marcin delivered multi-node synchronization by upgrading localnet and enabling cross-node consistency, focusing on production readiness and scalability. His work emphasized robust backend and full stack development, leveraging TypeScript and API design to ensure compatibility and performance. Although no bugs were fixed, Marcin’s contributions demonstrated depth in distributed systems engineering and improved the reliability of synchronization workflows.