Middle Frontend React Developer
⚲ Warszawa
5 000 - 8 000 USD netto (B2B)
Wymagania
- TypeScript
- Next.js
- React
- JavaScript
Opis stanowiska
About Shelf
The enterprise is going agentic and we are creating a unique operating system for an automated future.
Most AI agents break the moment they hit real business complexity. That’s why we built a platform that models a company's policies, workflows, and operational logic into an AI Data Model. Shelf enables AI Agents to reliably reason and deliver precise and reliable outcomes at scale.
We already have what most AI startups are still trying to earn: Enterprise customers such as Glovo, Nespresso, and HelloFresh, real production data, and tens of thousands of users. Customers trust us with operational knowledge: Our platform is highly reliable and secure with SOC2, HIPAA-ready security practices, and mature integrations in place.
About the Role
This role is for a frontend engineer with a few years of experience who wants to craft the interfaces that make enterprise AI accessible and trustworthy.
While others build chatbots, we're solving the harder problem: how do you build UIs that help users confidently navigate AI-powered systems processing millions of documents, while maintaining enterprise-grade reliability? You'll build production Next.js applications that handle complex state, real-time AI streaming, and real enterprise functionality, growing into the harder architectural calls over time. We obsess over frontend quality because we're building the trust layer for AI itself: when your interfaces handle edge cases gracefully, give clear feedback during AI processing, and stay fast under load, you directly enable users to trust AI-powered answers and make critical business decisions.
In our environment, AI isn't just what we build, it's how we build. You'll work alongside engineers who use AI coding assistants daily, build custom MCP servers, and experiment with new AI tooling to move faster.
This is a role for someone in a high-growth chapter of their career, who wants to do the best work of their life, learn fast, and win as part of a team going all-in on a hard mission.
What You Will Own
• Build and ship production Next.js applications with complex state and real-time AI interactions
• Build interfaces for AI-powered features: streaming LLM responses, semantic search, interactive knowledge graphs, and agentic builders
• Contribute to the component library and design system, keeping things reusable, accessible, and consistent
• Deliver enterprise-grade functionality: localization, accessibility, cross-browser support, and security best practices
• Help own what you ship after launch: monitor performance, optimize bundle sizes, and keep an eye on Core Web Vitals
• Use AI tools daily to move faster, and help improve internal frontend workflows
• Keep the bar high on code quality and testing through thoughtful code review
What Strong Performance Looks Like
• You turn vague product problems into shipped, well-reasoned interfaces that users trust
• Complex AI behavior feels legible and controllable to users because of how you built the UI
• Your components are reusable, accessible, and perform well under real load
• You bring momentum. Work moves because you are on it
What We Are Looking For
• Around 3 to 5 years of frontend engineering experience, with strong React and modern TypeScript
• Production Next.js experience: you've built and shipped SSR applications and understand the trade-offs between SSR, SSG, and CSR, with the appetite to go deeper
• Solid state management, with exposure to harder scenarios (real-time updates, optimistic UI, multi-tenant data) and the drive to grow there
• Experience building or contributing to AI/LLM interfaces: streaming responses, chat UIs, semantic search, or similar
• A feel for frontend performance: you care about Core Web Vitals and know the basics of improving them
• Exposure to enterprise application concerns: localization, accessibility, and security best practices
• 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 spot UX issues and propose solutions, and you're not satisfied with "good enough"
• AI-native working style. You already use AI coding assistants daily and are eager to push the boundaries of AI-assisted development
• Clear communication. You articulate design decisions and technical trade-offs clearly, verbally and in writing
Strong Plus
• Experience with React Flow, Highcharts, or other complex data-visualization libraries
• Hands-on experience with vector search UIs, RAG interfaces, or semantic search
• Familiarity with MCP, DSPy, or other cutting-edge AI frameworks, and building agentic AI interfaces
• Understanding of Node.js/Python backend fundamentals: you can read backend code and follow API design discussions
• Contributed to design systems or open-source component libraries
• A track record of growing fast and taking on more than your title strictly required
How We Evaluate Fit
We care more about craft, ownership, and the ability to make complex AI feel trustworthy than a perfect match to every library on paper. If you are the kind of engineer who can take a messy, complex enterprise problem and turn it into an interface people trust, we want to talk.
What Shelf Offers
• B2B contract
• Company stock options
• Hardware: MacBook Pro
• Modern technical stack. Develop open-source software
• A strong AI-native engineering environment with modern tools and room to experiment, including Claude Code, OpenAI Codex, and GitHub Copilot
Why Shelf
• Becoming one of the defining companies of the AI age is a hard plan, and our leadership team has the rare mix of deep AI, knowledge-management, and enterprise SaaS experience to actually execute it
• We have raised over $60 million in funding; our investors include Tiger Global, Insight Partners, Base10, and others
• Recognized by Gartner as a Cool Vendor, with high-velocity growth powered by the most innovative product in our category
• We love our customers and our customers love us. Ask a Shelf customer why, and they'll tell you it's our innovative capabilities and rock-solid reliability, that they enjoy working with our people, and most of all, the improvements they see in their business KPIs
• We're building fast across three hubs: our New York HQ and our Product and Engineering centers in Warsaw and Lviv
The enterprise is going agentic and we are creating a unique operating system for an automated future.
Most AI agents break the moment they hit real business complexity. That’s why we built a platform that models a company's policies, workflows, and operational logic into an AI Data Model. Shelf enables AI Agents to reliably reason and deliver precise and reliable outcomes at scale.
We already have what most AI startups are still trying to earn: Enterprise customers such as Glovo, Nespresso, and HelloFresh, real production data, and tens of thousands of users. Customers trust us with operational knowledge: Our platform is highly reliable and secure with SOC2, HIPAA-ready security practices, and mature integrations in place.
About the Role
This role is for a frontend engineer with a few years of experience who wants to craft the interfaces that make enterprise AI accessible and trustworthy.
While others build chatbots, we're solving the harder problem: how do you build UIs that help users confidently navigate AI-powered systems processing millions of documents, while maintaining enterprise-grade reliability? You'll build production Next.js applications that handle complex state, real-time AI streaming, and real enterprise functionality, growing into the harder architectural calls over time. We obsess over frontend quality because we're building the trust layer for AI itself: when your interfaces handle edge cases gracefully, give clear feedback during AI processing, and stay fast under load, you directly enable users to trust AI-powered answers and make critical business decisions.
In our environment, AI isn't just what we build, it's how we build. You'll work alongside engineers who use AI coding assistants daily, build custom MCP servers, and experiment with new AI tooling to move faster.
This is a role for someone in a high-growth chapter of their career, who wants to do the best work of their life, learn fast, and win as part of a team going all-in on a hard mission.
What You Will Own
• Build and ship production Next.js applications with complex state and real-time AI interactions
• Build interfaces for AI-powered features: streaming LLM responses, semantic search, interactive knowledge graphs, and agentic builders
• Contribute to the component library and design system, keeping things reusable, accessible, and consistent
• Deliver enterprise-grade functionality: localization, accessibility, cross-browser support, and security best practices
• Help own what you ship after launch: monitor performance, optimize bundle sizes, and keep an eye on Core Web Vitals
• Use AI tools daily to move faster, and help improve internal frontend workflows
• Keep the bar high on code quality and testing through thoughtful code review
What Strong Performance Looks Like
• You turn vague product problems into shipped, well-reasoned interfaces that users trust
• Complex AI behavior feels legible and controllable to users because of how you built the UI
• Your components are reusable, accessible, and perform well under real load
• You bring momentum. Work moves because you are on it
What We Are Looking For
• Around 3 to 5 years of frontend engineering experience, with strong React and modern TypeScript
• Production Next.js experience: you've built and shipped SSR applications and understand the trade-offs between SSR, SSG, and CSR, with the appetite to go deeper
• Solid state management, with exposure to harder scenarios (real-time updates, optimistic UI, multi-tenant data) and the drive to grow there
• Experience building or contributing to AI/LLM interfaces: streaming responses, chat UIs, semantic search, or similar
• A feel for frontend performance: you care about Core Web Vitals and know the basics of improving them
• Exposure to enterprise application concerns: localization, accessibility, and security best practices
• 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 spot UX issues and propose solutions, and you're not satisfied with "good enough"
• AI-native working style. You already use AI coding assistants daily and are eager to push the boundaries of AI-assisted development
• Clear communication. You articulate design decisions and technical trade-offs clearly, verbally and in writing
Strong Plus
• Experience with React Flow, Highcharts, or other complex data-visualization libraries
• Hands-on experience with vector search UIs, RAG interfaces, or semantic search
• Familiarity with MCP, DSPy, or other cutting-edge AI frameworks, and building agentic AI interfaces
• Understanding of Node.js/Python backend fundamentals: you can read backend code and follow API design discussions
• Contributed to design systems or open-source component libraries
• A track record of growing fast and taking on more than your title strictly required
How We Evaluate Fit
We care more about craft, ownership, and the ability to make complex AI feel trustworthy than a perfect match to every library on paper. If you are the kind of engineer who can take a messy, complex enterprise problem and turn it into an interface people trust, we want to talk.
What Shelf Offers
• B2B contract
• Company stock options
• Hardware: MacBook Pro
• Modern technical stack. Develop open-source software
• A strong AI-native engineering environment with modern tools and room to experiment, including Claude Code, OpenAI Codex, and GitHub Copilot
Why Shelf
• Becoming one of the defining companies of the AI age is a hard plan, and our leadership team has the rare mix of deep AI, knowledge-management, and enterprise SaaS experience to actually execute it
• We have raised over $60 million in funding; our investors include Tiger Global, Insight Partners, Base10, and others
• Recognized by Gartner as a Cool Vendor, with high-velocity growth powered by the most innovative product in our category
• We love our customers and our customers love us. Ask a Shelf customer why, and they'll tell you it's our innovative capabilities and rock-solid reliability, that they enjoy working with our people, and most of all, the improvements they see in their business KPIs
• We're building fast across three hubs: our New York HQ and our Product and Engineering centers in Warsaw and Lviv
🔍 Dekoder Ogłoszenia
🔴
growing into the harder architectural calls over time
Początkowo będziesz wykonywać proste zadania, a odpowiedzialność za architekturę będzie stopniowo przenoszona na Ciebie, co może oznaczać brak jasnej ścieżki rozwoju lub wsparcia.
🔴
We obsess over frontend quality
Może to oznaczać bardzo wysokie standardy jakości, które wymagają dodatkowego czasu i wysiłku, lub wręcz nadmierne skupienie na detalach kosztem innych aspektów pracy.
🟡
enterprise AI accessible and trustworthy
Praca nad interfejsami dla złożonych systemów AI, które mogą być trudne do zrozumienia i obsługi przez użytkowników biznesowych.
🟡
real production data
Będziesz pracować z rzeczywistymi danymi klientów, co wiąże się z odpowiedzialnością za ich bezpieczeństwo i prywatność.
🟡
tens of thousands of users
System, nad którym będziesz pracować, jest już używany przez dużą liczbę użytkowników, co może oznaczać presję związaną z utrzymaniem stabilności i wydajności.