Vasyl Semiliak
Frontend Engineer
Frontend engineer focused on React, TypeScript, and developer tooling.
10 years building product and platform work for B2B teams. Warsaw
GitHub activity
Experience
Corellium
Frontend systems engineer working across developer experience, platform foundations, design systems, and release quality for a US-based security SaaS company serving enterprise and government customers.
Focused on improving how frontend work gets done at scale — from reusable UI foundations and internal tooling to stronger engineering guardrails, faster builds, and a more reliable path to shipping.
- Built and evolved the internal design system foundation (React, Storybook, TypeScript, Tailwind), making frontend development faster and more consistent
- Improved developer experience through typed API contracts, CI checks, internal packages, and stronger engineering guardrails across the frontend stack
- Helped modernize core frontend foundations through stricter TypeScript, tooling upgrades, and build optimization, reducing friction in day-to-day development
- Strengthened release confidence, maintainability, and team velocity through platform-focused improvements across the product surface
- React
- TypeScript
- Next.js
- Storybook
- Tailwind
- Design Systems
- DX
- CI
Embedded product engineering
- React
- TypeScript
- GraphQL
- Fintech
- Healthcare
- REST codegen
- Full-Stack
- Fintech
- Crypto integrations
- Legacy modernization
AXSYS Inc.
- Zero-to-one
- Infrastructure
- Backend
- Integrations
Testimonials
via LinkedIn
An exceptionally skilled engineer with deep expertise in React, TypeScript, and Next.js. At Corellium he owned key DX initiatives — modernizing tooling, optimizing build pipelines, and bringing new tech into production thoughtfully.
OpenAI
Vasyl supported our company during a critical phase in the initial design of our solution. He made important design decisions that still have a significant impact years later.
Business Radar
Vasyl is someone you hand a problem to and stop worrying about it. Tight deadlines, changing requirements, the usual startup chaos — he delivered every time.
Hyre Sophie
A truly experienced senior frontend developer who thrives at managing and mentoring his team. Always at the forefront of new tech, and effortlessly bridges communication between business and engineering.
Rolique