Sergey Linnik contributed to ONLYOFFICE-PLUGINS/onlyofficehub.io.git and docker/mcp-registry, focusing on stability, integration, and developer experience. He implemented the ONLYOFFICE DocSpace Server integration in the MCP Registry, configuring server metadata, secrets, and environment variables to enable secure, scalable document storage connectivity. In JavaScript, Markdown, and YAML, Sergey addressed critical bugs by restoring image asset rendering for CV Builder and Zhipu plugins and updating documentation links to reflect current API locations. His work improved plugin reliability, reduced user-facing errors, and streamlined onboarding for SDKJS Plugins, demonstrating depth in configuration management, DevOps, documentation, and front-end development within complex environments.