Senior Frontend Engineer - Fintech Engineering (M/F/N)

InPost Pay is building its own fintech platform from the ground up. It’s a large-scale, international initiative where engineers will have the opportunity to shape the architecture, build core fintech components, and create solutions designed to operate at InPost’s scale. We’re building a lean, highly effective engineering organization in Poland, with AI-native engineering at its core. We’re looking for strong engineers who are comfortable with agentic engineering, from experienced professionals building complex systems and engineering tooling to a new generation of engineers who have embraced AI-driven development from the start of their careers. → Hybrid working model: preferably 1 day per week in the Warsaw or Cracow office. We're looking for a Senior Frontend Engineer to join our FinTech Platform team and help us build seamless payment experiences for consumers and merchants. In this role, you'll own consumer-facing and merchant-facing payment journeys, driving frontend architecture, performance engineering, and product quality. You'll work across modern web technologies, contributing to highly scalable and secure payment solutions. What will you work on? - designing and implementing microfrontend architecture across payment products and services, - owning performance engineering and continuously improving Core Web Vitals across customer-facing applications, - participating in the full development lifecycle, from requirements and specification through testing and release, - building integrations with backend services using GraphQL and REST APIs, - implementing real-time user experiences using Server-Sent Events and similar technologies, - developing secure payment-related user interfaces aligned with industry requirements and best practices, - contributing to frontend tooling, developer experience, and modern engineering workflow. This cooperation may be a strong match if you: - have at least 5 years of experience building modern frontend applications, - have hands-on experience with React, Vue, or Angular and TypeScript, - have experience designing and implementing microfrontend architectures, - have experience building and maintaining automated end-to-end tests using Playwright or similar frameworks, - understand frontend performance optimisation, Core Web Vitals, profiling, and bundle analysis, - have practical experience integrating REST and GraphQL APIs, - are familiar with OAuth2, OIDC, JWT, feature flags, and progressive delivery approaches, - actively use AI tools such as GitHub Copilot, ChatGPT, or Claude to improve development efficiency and quality, - communicate in English at B2 level or higher.Additional advantages: - experience in payments, fintech, or e-commerce products, - knowledge of PCI DSS requirements, CSP configuration, and secure browser-based architectures, - experience with WCAG accessibility standards, - backend development experience in Node.js, Java, Python, or C#, - experience building embeddable widgets or SDKs. What we offer: - the opportunity to build products that sit at the heart of InPost's growing financial services ecosystem, - ownership of business-critical solutions operating at scale, - a modern engineering environment focused on autonomy, accountability, and continuous learning, - collaboration with highly experienced product, engineering, and business teams, - access to cutting-edge technologies, event-driven architectures, and cloud-native solutions, - opportunities to shape technical standards, mentor others, and influence platform evolution, - full-time contract of employment.