Lead Front End Engineer (React)

📋 Description • Own the end-to-end front-end architecture for multiple green-field and brown-field products that serve millions of users in fintech, e-commerce, and enterprise SaaS. You will translate complex business requirements into elegant, performant React applications that scale across devices and geographies. • Lead a distributed squad of 4-8 front-end engineers located in Poland, Ukraine, and Spain. Run weekly architecture reviews, code-quality audits, and pair-programming sessions to maintain a 90%+ unit-test coverage and sub-second Lighthouse scores. • Establish and evangelize a component-driven design system in Storybook that unifies UI/UX across all client brands. You will define TypeScript contracts, accessibility standards (WCAG 2.1 AA), and automated visual-regression tests so that every new feature ships with pixel-perfect consistency. • Partner directly with product managers and UX researchers in San Francisco and London to shape roadmaps, prioritize epics, and validate prototypes through A/B experiments. Your insights will directly influence revenue-generating features worth >$5 M ARR. • Champion performance budgets, lazy-loading strategies, and SSR/SSG with Next.js to achieve <100 ms Time-to-First-Byte and <2 s Largest Contentful Paint on 3G networks. You will own Webpack and Vite build pipelines, tree-shaking, and bundle-analyzer reports. • Mentor mid-level and junior developers through structured learning paths, weekly 1:1s, and quarterly OKRs. Expect to see at least two of your mentees promoted to senior roles within 12 months. • Drive the adoption of cutting-edge tooling—React Server Components, GraphQL code-gen, micro-front-end federation, and edge-side rendering—while maintaining backward compatibility and zero-downtime deployments via blue-green releases on AWS. • Collaborate with backend teams using Node.js, Kotlin, and Python to design RESTful and GraphQL APIs that power real-time dashboards, payment flows, and AI-driven recommendation engines. You will co-own API contracts and ensure end-to-end type safety. • Act as the technical escalation point for client demos, security audits, and compliance reviews (GDPR, PCI-DSS). Your ability to present architecture decisions to C-level stakeholders will be critical for contract renewals and upsells. • Contribute to open-source initiatives under the company’s GitHub org, speak at React Warsaw meetups, and publish technical blog posts that position Rnrs Solutions as a thought leader in modern front-end engineering.