July 2, 2026

Senior Frontend Engineer (React)

Senior • Hybrid

8,000 - 12,000 USD/mo

Warsaw, Poland

Senior Frontend Engineer (React)

💰 Salary: $8000-$12,000
🕦 Full-time
☑️ B2B
🌴 Hybrid

We are looking for a Senior Frontend Engineer to join a fast-growing AI product company's engineering team. The role sits at the crossroads of frontend architecture and product experience, owning both the delivery of business-critical Next.js applications and the design of intuitive, trustworthy user experiences for agentic AI products.

Requirements

  • Over 5 years of frontend engineering experience, including 3+ years specializing in React and modern TypeScript.

  • Production Next.js experience: SSR applications at scale, app router, server components, and the trade-offs between SSR, SSG, and CSR.

  • Complex state management for hard scenarios: real-time collaboration, optimistic updates, multi-tenant isolation, large-scale data sync.

  • Experience building AI/LLM interfaces: streaming token responses, chat UIs, semantic search, or similar real-time AI interactions.

  • High-load performance work: you monitor Core Web Vitals and know how to improve them under heavy traffic and large datasets.

  • Enterprise application depth: localization, accessibility, security, and compliance, you understand the complexity beyond "making it work".

  • A security-conscious approach to engineering: you handle sensitive data carefully and think about the security implications of what you ship.

  • Strong craft and product instinct: you don't wait for perfect designs, you spot UX issues and propose solutions, and you're never satisfied with "good enough".

  • AI-native working style. You already use AI coding agents daily and are eager to push the boundaries of harness engineering.

  • Clear communication. You articulate design decisions and technical trade-offs clearly, verbally and in writing.

Key Responsibilities

  • Design and ship production Next.js SSR applications with complex state, high-load scenarios, and real-time AI interactions at scale.

  • Build interfaces for AI-powered features: streaming LLM responses, semantic search across millions of documents, interactive knowledge graphs, and agentic builders.

  • Architect component libraries and maintain the design system, ensuring reusability, accessibility, and consistent UX across the platform.

  • Deliver enterprise-grade functionality: localization, accessibility compliance, cross-browser support, and security.

  • Take full ownership after launch: monitor performance in production, optimize bundle sizes, instrument for Core Web Vitals, and ensure things scale gracefully.

  • Keep the bar high on code quality, testing, and craft through thoughtful code review and mentorship.

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Warsaw, MZ, Poland

30,000 - 45,000 USD

🏢 Summary: Opportunity for a Senior Front-End Developer to modernize and scale an existing web interface using React and Next.js. The role focuses on building high-quality, responsive UI components, integrating with backend services, and driving front-end architecture and best practices. You will collaborate with backend and data teams while ensuring performance, scalability, and code quality. 🗂️ Requirements: Minimum 5 years of hands-on experience with React and Next.js, Strong proficiency in JavaScript and TypeScript, Strong knowledge of HTML and CSS, Experience with RESTful APIs integration, Understanding of modern front-end architecture and design patterns, Experience with front-end testing frameworks, Experience with build tools, Ability to troubleshoot and resolve UI and performance issues 📃 Skills: React, Next.js, JavaScript, TypeScript, HTML, CSS, REST, gRPC-Web, CI/CD, Testing 🏢 Description: Senior Front-End Developer (React / Next.js) We are looking for a Front-End Developer to join a technology-focused team working on modern web applications. This role will play a key part in transforming an existing user interface into a modern, scalable front-end built with React and Next.js. You will be responsible for delivering responsive, high-quality user interfaces and contributing to the long-term evolution of the UI platform. The position involves close collaboration with backend and data teams, as well as ownership of front-end standards and best practices within the team. Responsibilities Redesign and modernize an existing web interface using React and Next.js Build reusable, maintainable UI components with TypeScript Act as a front-end subject matter expert, supporting ongoing improvements to usability and performance Integrate front-end applications with backend services via REST APIs (gRPC-Web knowledge is a plus) Identify, troubleshoot, and resolve UI and performance issues Contribute to code reviews, technical discussions, and CI/CD processes Ensure high code quality through testing, documentation, and adherence to best practices Required Skills & Experience Min. 5 years of hands-on experience with React and Next.js Strong proficiency in JavaScript/TypeScript, HTML, and CSS Solid understanding of modern front-end architecture and development patterns Experience working with RESTful APIs Familiarity with front-end testing frameworks and build tools is an advantage Experience in finances/banking - nice to have

Technology

dotLinkers

Senior Frontend Enigneer

Senior

Remote

Krakow, Poland

20,000 - 22,700 PLN/mo

🏢 Summary: Senior Frontend Engineer role focused on building and enhancing scalable web applications for a global e-commerce platform. The position involves designing high-quality, responsive user interfaces, optimizing performance, and contributing to frontend architecture using modern React and TypeScript ecosystems. You will collaborate with cross-functional teams to deliver robust, reusable, and maintainable frontend solutions. 🗂️ Requirements: Degree in Computer Science or equivalent experience, 4+ years of software engineering experience, Commercial experience in building production web applications, Strong proficiency in TypeScript including generics and strict mode, Expertise in React ecosystem including React 19 and React Router, Experience with modern bundlers, Experience with micro-frontend architecture and Module Federation, Experience with state management libraries, Experience with data-fetching libraries, Experience with unit and E2E testing, Experience publishing internal packages and Semantic Versioning, Experience with CI/CD pipelines and release workflows, Understanding of cloud computing principles, Experience with SQL and relational databases, Knowledge of API design and distributed applications 📃 Skills: JavaScript, TypeScript, React, ReactRouter, Rsbuild, Webpack, Vite, ModuleFederation, Zustand, TanStackQuery, RxJS, HeroUI, Tailwind, Jest, TestingLibrary, Playwright, Azure, Kubernetes, AzureDevOps, GitHubActions, Jenkins, SQL, MySQL, PostgreSQL 🏢 Description: Position: Senior Frontend Engineer Type of contract: COE (UoP) up to 22 700 PLN gross/month Working model: fully remote You can join our client and work on a modern digital platform designed to better connect shoppers and retailers within the global e-commerce ecosystem. The project focuses on building and enhancing scalable web applications and core services that power user interactions. You’ll collaborate closely with product and design teams to deliver intuitive, high-performance user experiences. The environment emphasizes innovation, usability, and continuous improvement of frontend architecture. Role summary: As a Senior Engineer, you will take ownership of designing and developing responsive, high-quality user interfaces while collaborating with cross-functional teams. The role involves translating UI/UX designs into functional applications, improving performance, and ensuring consistency through reusable components. You’ll also contribute to code quality through reviews and support architectural decisions. The position requires strong expertise in modern frontend technologies, especially React and TypeScript, along with experience in scalable application development. Responsibilities: Design and develop modern, responsive user interfaces Collaborate with designers, backend engineers, and DevOps teams Review code and maintain high engineering standards Build reusable UI components and optimize performance Ensure cross-browser compatibility and accessibility Key requirements: Degree in Computer Science (or equivalent experience) 4+ years of experience in software engineering Hands-on experience in writing production code for web applications; Practical knowledge in front-end technologies such as JavaScript, TypeScript, CSS, HTML, with strong proficiency in TypeScript (generics, type-safe APIs, strict mode); Expertise in the React ecosystem including React 19, React Router, modern bundlers (Rsbuild/Webpack/Vite), and micro-frontend architectures (Module Federation); Experience with state management and data-fetching libraries such as Zustand, TanStack React Query, and reactive patterns with RxJS; Familiarity with modern component libraries and styling toolchains-  HeroUI, Tailwind CSS, design-token-driven theming; Experience with unit and E2E testing frameworks such as Jest, Testing Library, and Playwright; Experience working with internal packages and publishing them to a private registry and Semantic Versioning; Familiarity with CI/CD pipelines and release workflows- Azure DevOps, GitHub Actions, or Jenkins- including PR validation, artifact promotion, and multi-environment deploys; An understanding of cloud computing principles and practices; experience with production applications in cloud environments. Azure and Kubernetes experience is preferred; Knowledge in key programming concepts like memory management, optimization techniques, API design, relational mapping frameworks, and distributed applications; An understanding of database concepts and experience writing SQL in a relational database such as MySQL or PostgreSQL; Familiarity with monitoring and logging solutions; Self-starter who can move projects forward by filling in the gaps on Agile teams, from delivering complete, well-defined functionalities with high quality standards, through reviewing other Engineers’ code to contributing to design sessions. Offer: COE, up to 22 700 PLN gross per month Private healthcare, life insurance, sports card, and lunch subsidy Learning and development support (including tuition assistance) Employee Assistance Program Remote or hybrid work model supporting work–life balance Opportunity to collaborate with experienced engineers on global-scale e-commerce solutions