Welcome, I'm Vitalii. 👋

Zippia is the kind of product where small frontend changes don't stay small. I worked on performance-critical user flows and shared frontend infrastructure in a large React application, where stability and long-term maintainability mattered as much as shipping features.

• Architected and owned a reusable onboarding framework in a large React application, powering multiple form-heavy flows used by up to 7M users per month and designed to support frequent product changes at scale.
• Refactored and restructured critical user flows and supporting UI architecture, reducing bundle size by ~25% and improving task completion speed by ~40% on key paths.
• Built and owned a Chrome extension used by 6,000+ daily users to automate ATS applications, reducing end-to-end application time from ~30 minutes to under 2 minutes.

How I worked: focused on owning high-impact frontend systems, making changes that remained stable under scale, frequent iteration, and real user traffic.

At Devlion, my work focused on improving the health of an existing production React codebase, addressing performance bottlenecks, correctness issues, and long-term maintainability in a live environment.

• Improved first paint performance in a production React application by investigating rendering and asset-loading bottlenecks, reducing initial load times by ~20-30% across core pages.
• Migrated a production React codebase to TypeScript, planning and executing the transition to minimize risk while reducing runtime defects and improving long-term maintainability.
• Built an analytics dashboard for eBay sellers, investigating and resolving data consistency and edge-case issues to ensure reliable reporting of business metrics.

How I worked: made incremental, low-risk improvements in production systems, prioritizing correctness, performance, and maintainability over short-term wins.

Freelance work meant full ownership. I built and shipped complete web products, handling frontend, backend, and data so the entire system worked together in production.

• Improved end-to-end page load performance of a production e-commerce application built with Next.js + PostgreSQL, cutting perceived load times by up to ~50% through query optimization and frontend rendering improvements.
• Built a community platform supporting event management and fundraiser tracking, owning backend data models and frontend flows used by organizers.
• Implemented real-time React interfaces using WebSockets for live market data and trading interactions, handling update frequency, UI consistency, and connection stability.

How I worked: worked end-to-end, owning technical decisions across frontend, backend, and data while staying close to stakeholders and real production constraints.