Looks like you have JavaScript disabled. For the full Twine experience, you will need to re-enable it.

- Senior Frontend Engineer with 7+ years of commercial experience building scalable FinTech products using React and TypeScript. - English: B2. Polish: B2. - The right to work legally in Poland without support from a company. - I created Split.io analogue myself from the front-end part - _Website not available. Sign in: https://www.twine.net/signup_ - Experienced in frontend architecture, performance optimization, mentoring engineers, and delivering complex business applications used by thousands of customers. - Support, refinement, and refactoring of complex client-side business logic for FinTech applications, ensuring the stable operation of key functionality. - Participated in code reviews and provided constructive feedback. - Troubleshooting and debugging issues to improve performance and reliability.…- Senior Frontend Engineer with 7+ years of commercial experience building scalable FinTech products using React and TypeScript. - English: B2. Polish: B2. - The right to work legally in Poland without support from a company. - I created Split.io analogue myself from the front-end part - _Website not available. Sign in: https://www.twine.net/signup_ - Experienced in frontend architecture, performance optimization, mentoring engineers, and delivering complex business applications used by thousands of customers. - Support, refinement, and refactoring of complex client-side business logic for FinTech applications, ensuring the stable operation of key functionality. - Participated in code reviews and provided constructive feedback. - Troubleshooting and debugging issues to improve performance and reliability.

Siarhei Chaptsau

Front-End Developer, Web Developer





- Senior Frontend Engineer with 7+ years of commercial experience building scalable FinTech products using React and TypeScript. - English: B2. Polish: B2. - The right to work legally in Poland without support from a company. - I created Split.io analogue myself from the front-end part - _Website not available. Sign in: https://www.twine.net/signup_ - Experienced in frontend architecture, performance optimization, mentoring engineers, and delivering complex business applications used by thousands of customers. - Support, refinement, and refactoring of complex client-side business logic for FinTech applications, ensuring the stable operation of key functionality. - Participated in code reviews and provided constructive feedback. - Troubleshooting and debugging issues to improve performance and reliability.…- Senior Frontend Engineer with 7+ years of commercial experience building scalable FinTech products using React and TypeScript. - English: B2. Polish: B2. - The right to work legally in Poland without support from a company. - I created Split.io analogue myself from the front-end part - _Website not available. Sign in: https://www.twine.net/signup_ - Experienced in frontend architecture, performance optimization, mentoring engineers, and delivering complex business applications used by thousands of customers. - Support, refinement, and refactoring of complex client-side business logic for FinTech applications, ensuring the stable operation of key functionality. - Participated in code reviews and provided constructive feedback. - Troubleshooting and debugging issues to improve performance and reliability.

Available to hire

Wroclaw, Poland

Senior Frontend Engineer with 7+ years of commercial experience building scalable FinTech products using React and TypeScript.
English: B2. Polish: B2.
The right to work legally in Poland without support from a company.
I created Split.io analogue myself from the front-end part - Website not available. Sign in: https://www.twine.net/signup
Experienced in frontend architecture, performance optimization, mentoring engineers, and delivering complex business applications used by thousands of customers.
Support, refinement, and refactoring of complex client-side business logic for FinTech applications, ensuring the stable operation of key functionality.
Participated in code reviews and provided constructive feedback.
Troubleshooting and debugging issues to improve performance and reliability.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Beginner

Beginner

Language

Russian

Fluent

Polish

Advanced

English

Advanced

Work Experience

Senior Frontend Developer at Plazo Technologies / FinTech

March 1, 2023 - October 1, 2025

Built and maintained scalable FinTech web products using React and TypeScript. Performed frontend architecture decisions and performance optimization. Supported and refactored complex client-side business logic for FinTech applications used by thousands of customers. Mentored engineers, participated in code reviews, and provided constructive feedback. Troubleshot and debugged issues to improve performance and reliability.

Senior Frontend Developer at ID Finance / FinTech

September 1, 2018 - March 1, 2023

Developed internal web applications for managing project sprints and resource planning with frontend architecture inspired by BambooHR. Mentored 6 junior full-stack developers and coordinated work in a 7–10 person frontend team and 12–15 across cross-functional teams. Individually developed and completed Reficio.io, an A/B testing application with user-friendly UI. Built scalable FinTech platforms including CRM, client area, and registration systems. Worked on React-based development and refactoring, integrating many third-party APIs, scaling functionality across company applications, and improving performance and reliability through debugging and code reviews.

Economist (Finance and Economics Department)

January 1, 2012 - January 1, 2018

Prepared financial statements, pricing and calculation calculations. Accounted for financial flows, distribution of income and expenses, and interacted with banks.