Senior/Lead React Developer

Project/Client: Banking Location: Baltic states + Poland Seniority: Senior / Lead Language: English Role Overview: As a Senior Frontend Engineer , you will play a key role in building a modern React -based micro-frontend architecture for banking systems. You will design and implement scalable frontend modules, develop high-quality user interfaces for Back Office applications, and ensure performance, security, and maintainability across the platform. This is a hands-on role combining technical leadership and active development, suited for an engineer experienced in React , TypeScript , and complex enterprise environments, working with backend integrations via REST APIs and GraphQL . Key Responsibilities: Lead and mentor a team of React developers, providing technical guidance and conducting code reviews Design and implement scalable micro-frontend architecture using modern frontend tooling Develop high-quality frontend solutions using React , TypeScript , and state management ( Redux , Zustand , Context API ) Build and maintain reusable UI components, shared libraries, and design systems Collaborate with backend teams on integrations via REST APIs and GraphQL Ensure best practices in performance, security, and accessibility Contribute to CI/CD , automated testing ( Vitest , React Testing Library , Playwright ), and code quality improvements Utilize modern development workflows, including AI-assisted tools (e.g., Copilot , Bmad workflow ) Must-Have Requirements: 5+ years of experience in frontend development with strong expertise in React Strong proficiency in TypeScript and modern JavaScript (ES6+) Hands-on experience with micro-frontend architecture Experience with state management solutions ( Redux , Zustand , Context API ) Experience using AI-assisted development tools (e.g., Copilot ) Solid understanding of CSS , SASS , and responsive design principles Experience with testing frameworks such as Vitest , React Testing Library , and Playwright Familiarity with CI/CD , Git , and Agile development practices Strong understanding of REST APIs , GraphQL , and frontend-backend integration Experience mentoring developers and leading technical decisions Nice to Have: Experience in banking or enterprise environments Knowledge of backend technologies such as Java , Spring Boot , Spring Security Familiarity with event-driven architectures (e.g., Kafka ) What we offer Model: B2B contract with Bonapolia - one contract, one monthly invoice Rate: negotiated per candidate seniority and client budget Payment: monthly invoice, paid on the same schedule the client pays us (usually 30 days) Contract written under your country's law We handle the client-side paperwork: MSA, NDA, invoicing 🏢 About Bonapolia Bonapolia is a family-owned IT staff augmentation team based in Lisbon. We build engineering teams for product companies and IT consultancies across Europe and the US. More at 📩 Ready to Join? We look forward to receiving your application and welcoming you to our team! Originally posted on Himalayas