Andrey contributed to both the sveltejs/svelte and zed-industries/zed repositories, focusing on targeted improvements in CSS and TypeScript tooling. In Svelte, he addressed a nuanced bug in CSS animation scoping by introducing a helper to detect global block context, ensuring keyframes inside global CSS blocks remained local and preventing unintended animation prefixing. This work, implemented with TypeScript and CSS, improved styling predictability and reduced regressions. Later, in the Zed project, Andrey enhanced TypeScript code quality enforcement by integrating TypeScript file support into the ESLint flat configuration, streamlining linting and configuration management for TypeScript projects using Rust and ESLint.