Sr Frontend Developer (React; 100% remote)

About project We are seeking an accomplished and UI-focused Senior Frontend Engineer to lead the architectural evolution and user experience of an internal platform for laboratory management. In this role, 90% of your focus will be dedicated to designing, building, and scaling a modern React and TypeScript web application that will progressively replace legacy Airtable and server-rendered interfaces. You will champion responsive design, component architecture, modern state management, design system alignment, and end-to-end user workflows. The remaining 10% of your scope will involve light backend collaboration with existing Node.js/TypeScript APIs to ensure seamless, type-safe integration. The engineer will adopt established team workflows and spec-driven engineering practices—aligned with the Claude SDLC methodology—to rapidly build high-quality web applications while maintaining strong engineering rigor. 100% remote work.TasksFrontend Architecture & UI Development (Primary Focus ~90%)Client-State & API IntegrationBackend & Integration Support (~10% Focus)Authentication & Application SecurityData & MessagingTesting & QualityAgentic & Spec-Driven EngineeringDevOps & OperationsStakeholder CollaborationExpectationsBachelor's degree in Computer Science, Software Engineering, or a related field, or equivalent professional experience.Deep expertise with modern React, TypeScript, state management libraries, and component-driven architecture.Proven track record building enterprise web applications, data dashboards, complex form flows, and design systems.Proficiency with modern frontend build systems (e.g., Vite), CSS-in-JS / Tailwind, and UI component libraries.Experience writing frontend tests with React Testing Library, Vitest, or Cypress/Playwright.Solid understanding of RESTful API design, HTTP/JSON contracts, client-side caching, and type generation (e.g., Zod, OpenAPI).Working knowledge of Node.js and TypeScript backends to effectively collaborate on full-stack interfaces.Practical knowledge of OAuth 2.0 and secure web application development.Experience with SAML 2.0, PingFederate, or another enterprise identity provider is highly desirable.Experience with Google Workspace APIs, service accounts, and domain-wide delegation is desirable.Experience with runtime schema validation using Zod or a comparable library.Strong automated-testing skills; experience with Vitest and React Testing Library is desirable.Experience with Docker, Kubernetes, and CI/CD pipelines.Familiarity with event-driven systems, message brokers, scheduled jobs, and transactional outbox patterns is desirable.Ability to troubleshoot distributed integration flows across application, identity, network, and infrastructure boundaries.Excellent communication and collaboration skills in English.Ability to work independently and take ownership in a dynamic, cross-functional environment.We offerOngoing support from a dedicated agent, taking care of your project continuity, client contact, necessary formalities, work comfort and development, Consultant Development Program – advice on growth planning based on the latest trends and market needs in IT, including consultations with agents and growth mentors, Access to 7N Learning & Development – a development and educational platform with webinars, a library of articles and industry reports, and regular invitations to one-time and recurring development events – technical, business, and lifestyle, Spectacular integration events, both for you (e.g., annual Kick-Off trip, Christmas parties, or Summer Olympics sports events) and for your loved ones (e.g., family picnics, movie premieres), Professional development not only during the project – you can get involved in knowledge transfer to others within the 7N Services offering directed at 7N clients, Relationships and access to the knowledge of the most experienced IT experts in the market – the average professional tenure of our consultants in Poland is over 10 years, A complete benefits package, including funding for medical care, life insurance, sports cards for you and your loved ones, as well as discounts in stores in Poland and abroad.About 7NConstantly searching for projects, difficult rate negotiations, lack of development support – sounds familiar? At 7N, you gain not only stability of contracts but also the personal involvement of a dedicated agent who ensures your professional comfort and continuous access to development initiatives.Our mission is to provide stable and rewarding collaborations that drive your success as an IT expert and the success of our clients. We build long-lasting relationships based on Scandinavian values and 30 years of experience creating IT solutions for over 200 organizati