I am a Ukrainian professional currently based in Spain since September 2025, with a background in law and business before transitioning into software development. My legal education and experience running a business gave me a strong foundation in structured thinking, responsibility, and understanding real-world product needs. I later moved into programming, where I have built a solid career as a full-stack developer working with international teams. I value long-term collaboration, ownership, and building reliable, high-quality products. I'm a full-stack developer with 5+ years of experience building scalable SaaS and web applications in RegTech, fintech, and product-based environments. I thrive on delivering end-to-end features and collaborating with distributed teams to ship reliable, performant software. I specialize in React and Node.js with TypeScript, REST APIs, database design, cloud infrastructure, and performance optimization. I value code quality, maintainability, and using AI-powered development assistants to accelerate delivery and solve problems.…

Serhii Voloshyn

I am a Ukrainian professional currently based in Spain since September 2025, with a background in law and business before transitioning into software development. My legal education and experience running a business gave me a strong foundation in structured thinking, responsibility, and understanding real-world product needs. I later moved into programming, where I have built a solid career as a full-stack developer working with international teams. I value long-term collaboration, ownership, and building reliable, high-quality products. I'm a full-stack developer with 5+ years of experience building scalable SaaS and web applications in RegTech, fintech, and product-based environments. I thrive on delivering end-to-end features and collaborating with distributed teams to ship reliable, performant software. I specialize in React and Node.js with TypeScript, REST APIs, database design, cloud infrastructure, and performance optimization. I value code quality, maintainability, and using AI-powered development assistants to accelerate delivery and solve problems.…

Available to hire

I am a Ukrainian professional currently based in Spain since September 2025, with a background in law and business before transitioning into software development. My legal education and experience running a business gave me a strong foundation in structured thinking, responsibility, and understanding real-world product needs. I later moved into programming, where I have built a solid career as a full-stack developer working with international teams. I value long-term collaboration, ownership, and building reliable, high-quality products.

I’m a full-stack developer with 5+ years of experience building scalable SaaS and web applications in RegTech, fintech, and product-based environments. I thrive on delivering end-to-end features and collaborating with distributed teams to ship reliable, performant software.

I specialize in React and Node.js with TypeScript, REST APIs, database design, cloud infrastructure, and performance optimization. I value code quality, maintainability, and using AI-powered development assistants to accelerate delivery and solve problems.

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Skills

Experience Level

TypeScript
Expert
Docker
Expert
React JS
Expert
Node.js
Expert
JavaScript
Expert
AWS
Expert
Express
Expert
PostgreSQL
Expert
CSS
Expert
MongoDB
Expert
HTML5
Expert
GraphQL
Expert
GitHub
Expert
MySQL
Expert
Jira
Expert
Stripe
Expert
Kubernetes
Intermediate
Selenium
Intermediate
DynamoDB
Intermediate
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Language

English
Advanced
Ukrainian
Fluent
Russian
Fluent
Polish
Intermediate
Spanish; Castilian
Beginner

Work Experience

Full-Stack Developer at RegDesk, Inc.
December 1, 2021 - January 1, 2026
Developing and maintaining a complex RegTech SaaS platform. Building full-cycle features on frontend and backend. Working with React, Node.js, TypeScript, and cloud services. Designing, implementing, and optimizing REST APIs. Creating and maintaining database schemas and data models. Improving application performance and fixing production issues. Monitoring errors and stability with Sentry. Participating in code reviews, sprint planning, and technical discussions. Collaborating with product managers, designers, and QA engineers.
Frontend Developer at Infinity Swap
July 1, 2021 - September 1, 2022
Developed UI components for a fintech/crypto web application. Built reusable components using React and Next.js. Integrated frontend with backend APIs. Worked closely with designers using Figma. Improved UI performance and fixed frontend bugs.
Full-Stack Developer at Web AI Studio
March 1, 2020 - December 1, 2021
Developed full-stack web applications from scratch. Designed and implemented backend services using Node.js and NestJS. Built and maintained REST APIs. Worked with PostgreSQL and MongoDB. Integrated Stripe/Stripe Connect payment systems. Participated in architectural decisions and code reviews.
Frontend Developer (Part-time) at Infinity Swap
July 1, 2021 - September 1, 2022
Developed UI components for a fintech/crypto web app; built reusable components with React/Next.js; integrated frontend with backend APIs; collaborated with designers in Figma; improved UI performance and fixed frontend bugs.
Full-Stack Developer (Contract) at Web AI Studio
March 1, 2020 - December 1, 2021
Developed full-stack web applications; designed backend services with Node.js and NestJS; built and maintained REST APIs; worked with PostgreSQL and MongoDB; integrated Stripe; participated in architecture decisions and code reviews.

Education

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Qualifications

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Industry Experience

Software & Internet, Financial Services, Professional Services, Other
    paper Navifit Meal Plans app

    Web and mobile application I developed from scratch. I was responsible for the entire stack, including frontend development, backend APIs, database design, and deployment, while also acting as the technical lead. I worked directly with the client to define requirements, translate business needs into technical solutions, and deliver the product end to end, with only a designer involved separately for UI/UX.

    This project was especially meaningful because it combined technical complexity with real user impact in the health and wellness space. The main challenge was designing a scalable architecture while ensuring a smooth and intuitive user experience across both web and mobile platforms. Building everything from the ground up required strong ownership, careful technical decisions, and constant iteration based on user feedback, which significantly strengthened my skills as a full-stack developer and product-oriented engineer.