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I will develop complex react web applications
Andrew Kasian
About this gig
Some React projects are simple: a form, a few pages, done in a few days. Others involve complex state, multiple data sources, permission logic, or a codebase with years of decisions baked into it. This Gig is for the second kind.
I work on React and TypeScript applications with real complexity. My background includes a data browsing tool with a virtualized, lazy-loaded file tree, a structured content viewer, a query-based search interface with saved queries, and a separate dashboard builder that turns query results into charts and tables, plus improving TypeScript adoption and testing strategy across teams at an enterprise SaaS company.
This Gig covers new feature development, refactoring parts of an existing React application, or building a custom application from a defined scope. I do not build backend systems, but I integrate cleanly with whatever API or data layer you already have.
Over 10 years of experience building React and TypeScript applications for SaaS products, enterprise platforms, and large business systems.
Before ordering, send a short description of your application, the screens or features involved, and your current tech stack.
Respect third-party rights
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Get to know Andrew Kasian
Andrew Kasian
Senior Frontend Engineer
- FromUkraine
- Member sinceJul 2026
Languages
Ukrainian, Russian, English
I am a Senior Frontend Engineer with 10+ years of experience building complex React, Angular, and TypeScript applications for SaaS and enterprise products.
I specialize in admin dashboards, workflow-heavy interfaces, frontend architecture, performance optimization, and modernization of mature codebases.
My experience includes improving bundle size by 38%, application performance by 30–35%, and leading a frontend organization of 17+ engineers.
I focus on reliable, maintainable frontend solutions that are ready for real business use.
My Portfolio
FAQ
Do you build the backend or API?
No. This Gig covers the frontend. I integrate with your existing API or work with mock data while it's being prepared.
Can you work inside my existing React codebase?
Yes — this is a core part of this Gig. I follow your current architecture, component patterns, and coding standards rather than introducing a parallel structure. Repository access is required before the final scope is confirmed.
Do you write tests?
Test coverage (unit or component-level) is included in the Advanced package. It can be added to Foundation or Production as a scoped addition if needed.
What if my project doesn't fit neatly into one of the three packages?
Message me with a description of the work before ordering — I can scope a custom offer if your project falls between packages or needs a different structure.
Do you provide support after delivery?
I include revisions during delivery and fix defects related to the delivered scope for 7 days after final approval. New features or scope changes are estimated separately.
