Senior Frontend Engineer, React & Next.js

B-Stock is the world's largest B2B re-commerce platform, connecting sellers and buyers of returned, trade-in, and overstock inventory. They are seeking an experienced Senior Frontend Engineer to lead the technical direction of their marketplace experience, focusing on architecting and implementing features within Next.js-based applications while mentoring engineers and collaborating with stakeholders.

Responsibilities:

• Lead architectural design and implementation of complex features in our Next.js/React customer-facing applications
• Make critical technical decisions balancing user experience, developer experience, scalability, and business requirements
• Drive technical strategy for frontend architecture, including state management, performance optimization, and build tooling
• Evaluate and introduce new technologies and patterns to improve development velocity and product quality
• Own end-to-end delivery of high-complexity, high-visibility features from concept through production
• Establish and enforce frontend engineering best practices, code quality standards, and testing strategies
• Participate in technical discussions with non-technical stakeholders, translating business requirements into technical solutions
• Represent engineering perspective in product planning, advocating for technical sustainability and user experience
• Collaborate with engineering leadership on strategic initiatives, technical roadmaps, and critical decision-making
• Partner with UX designers to influence design direction based on technical constraints and opportunities
• Communicate technical complexity and tradeoffs clearly to diverse audiences including product, design, and leadership
• Mentor mid-level and senior engineers through code review, pairing, and technical guidance
• Elevate team capabilities by sharing knowledge on modern frontend patterns, Next.js ecosystem, and performance optimization
• Foster a culture of engineering excellence, continuous improvement, and collaborative problem-solving
• Guide engineers through complex technical challenges and help them grow their architectural thinking
• Write production-quality TypeScript/React code for our customer-facing applications
• Implement sophisticated UI interactions, real-time bidding interfaces, and responsive layouts
• Optimize application performance including bundle size, Core Web Vitals, and runtime efficiency
• Debug and resolve complex issues spanning frontend, API integration, and full-stack concerns
• Conduct thorough code reviews ensuring quality, maintainability, and knowledge transfer
• Build with accessibility, security, and scalability as foundational requirements
• Integrate monitoring, logging, and observability tools (Datadog) for production debugging
• Manage feature flag strategies using LaunchDarkly for safe, incremental rollouts
• Ensure cross-browser compatibility and responsive design across devices
• Implement comprehensive testing strategies using Jest, Vitest, React Testing Library, and Playwright
• Design and implement authentication/authorization flows with multiple identity providers (OAuth2, FusionAuth, Salesforce, JWTs)

Requirements:

• Bachelor's degree in Computer Science or equivalent experience
• 10+ years of professional software engineering experience
• 7+ years focused on frontend development
• 5+ years of production experience with React and modern frontend frameworks
• 3+ years working with Next.js or similar SSR/hybrid rendering frameworks
• Proven track record architecting and delivering large-scale, customer-facing SaaS applications
• Experience leading technical initiatives and mentoring engineers at various levels
• Demonstrated ability to drive projects from ambiguous requirements to successful production launch
• Experience working on high-pressure, high-visibility projects with executive stakeholder involvement
• Expert-level proficiency in TypeScript, React 18+, and Next.js 15+ (App Router and Pages Router)
• Deep understanding of modern frontend architecture including state management (TanStack Query, Context API)
• Strong knowledge of CSS-in-JS solutions (styled-components) and responsive design patterns
• Proficiency with frontend tooling: Webpack, Vite, Babel, ESLint, Prettier
• Experience with testing frameworks: Jest, Vitest, React Testing Library, Playwright
• Strong understanding of web performance optimization and Core Web Vitals
• Familiarity with backend technologies and API design (RESTful, GraphQL)
• Experience with CI/CD pipelines and containerized deployments (Docker, Kubernetes)
• Git workflow expertise including pull request reviews and collaborative development
• Experience with microservices architecture and event-driven systems
• Knowledge of feature flag management and experimentation platforms
• Familiarity with monitoring and observability tools (Datadog, Sentry)
• Experience with design systems and component library development
• Understanding of e-commerce, marketplace, or auction platforms
• Exposure to MongoDB, RabbitMQ, or similar backend technologies