Lassi Polonen developed robust infrastructure features across the awslabs/amazon-eks-ami and neondatabase/neon repositories, focusing on storage, observability, and security. He implemented RAID-10 local NVMe storage support for EKS worker nodes, updating documentation, APIs, and bootstrap scripts to streamline provisioning and optimize performance using Go and Shell. In neondatabase/neon, Lassi enhanced audit logging by adding metadata and RFC5424 JSON formatting, improving traceability and compliance. He further secured audit log transmission by enabling TLS support, refactoring rsyslog configuration in Rust, and introducing unit tests. His work demonstrated depth in system administration, configuration management, and network security within cloud-native environments.