Frontend Engineer (React)

About the role

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.

Location – Warsaw, work from the office.

FRONTEND REACT ENGINEER:

This role is for Senior frontend engineers who can design and own business-critical user experiences for agentic AI products.

We want someone who is strong technically, has strong UI judgment, communicates clearly, and has the taste to make complex product experiences simpler, faster, more trustworthy, and easier to evolve over time. Expect real ownership from frontend architecture through production quality. You will build production Next.js applications with complex state, real-time AI interactions, and multiple layers of enterprise functionality.

The team is small enough for engineers to make real decisions. Career growth comes from ownership. Titles matter less than the scope you can carry. The people who grow fastest take responsibility for larger product surfaces, drive customer outcomes, and strive to develop better engineering practices.

You solve ambiguous frontend problems by understanding the user need, shaping the right interaction model, then shipping, iterating, and keeping the experience healthy in production.

We build AI-native. Engineers use Codex, Claude Code, and agents they build themselves. We invest in harness engineering through skills, CLIs, logs, traces, and orchestration.

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

- 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