Ivaylo Ivanov upgraded core Cloud Foundry CPI repositories, including cloudfoundry/bosh and cloudfoundry/bosh-aws-cpi-release, to support API version 3, focusing on robust API development and versioning. He refactored configuration handling and improved YAML tag parsing to ensure accurate runtime configuration management. In the AWS CPI codebase, Ivaylo enhanced stemcell AMI tagging workflows, aligning them with updated API requirements and AWS mock behaviors. He stabilized unit tests and improved CI reliability by updating test suites and mocks to reflect API changes. His work, primarily in Ruby and YAML, strengthened production readiness and reduced upgrade risk for future CPI enhancements.