Senior Frontend Developer (React) at 247Bet

Role Description

• This is a full-time hybrid role for a Senior Frontend Developer, based in Lagos — hybrid, with 3 days per week in the office. You'll build the web experience where customers browse live odds, build bet slips, follow and copy other bettors, and move money — all updating in real time, all needing to feel instant on mid-range devices over inconsistent networks. Our web stack is React and Next.js against a BFF layer. This is a hands-on role for a frontend engineer who cares about performance as much as pixels, and who understands that in betting, a laggy odds update or a double-submitted bet slip is a real problem, not a polish issue.What You'll Do
• Build and own core web experiences in React/Next.js: sportsbook browsing, bet slip, wallet, account, and social/copy-betting features
• Implement real-time UI — live odds updates, in-play markets, and cash-out values — over WebSockets with graceful degradation
• Engineer for performance on the devices and networks our customers actually use: bundle discipline, lazy loading, and aggressive optimisation of Core Web Vitals
• Handle the hard frontend states well: optimistic updates, retries, idempotent submissions, offline/reconnect behaviour
• Collaborate with design to ship polished, responsive interfaces, and with backend engineers on clean BFF contracts
• Write well-tested code (unit, integration, and E2E) and participate in code reviews
• Instrument the frontend with analytics and error monitoring, and use the data to drive improvements
• Uphold accessibility and responsible gambling UI requirements across the product
• Mentor mid-level frontend engineers and help set standards for the frontend codebase

What We're Looking For

• 5+ years of frontend engineering experience with deep, current expertise in React and TypeScript
• Strong production experience with Next.js (SSR/ISR, routing, performance patterns)
• Proven experience building real-time interfaces (WebSockets, SSE) and managing complex client state
• A demonstrated performance mindset — you can talk concretely about how you've made a slow app fast
• Solid testing habits with tools like Jest, React Testing Library, Playwright, or Cypress
• Good grasp of web security fundamentals for applications that handle money
• Strong collaboration with designers and backend engineers
• A portfolio, live product, or GitHub work you're proud to walk us through

Nice to Have

• Experience building betting, trading, gaming, or fintech interfaces
• Experience shipping web products for African markets and low-bandwidth conditions
• Familiarity with design systems and component library ownership
• Exposure to A/B testing and growth experimentation tooling