Senior Frontend Engineer - React & Expo CrossPlatform Developer

Overview

Job Title:

Senior Frontend Engineer - React/Expo Migration Specialist Salary:

$95,000 - $120,000 base + quarterly performance bonuses + benefits Employment Type:

Full-time, Direct Hire How to Apply:

Please apply here: https://forms.gle/eSiEAwwg6DrA3JZh9 Note: This posting may include references to application links and timelines; only candidates are invited to apply. About the Role

The Mission Transform our profitable SaaS platform (currently serving thousands of paying customers) into a modern cross-platform application while maintaining zero downtime and preserving all existing functionality. You will architect and implement a gradual migration strategy that allows us to ship improvements incrementally while users continue their daily operations uninterrupted. What You'll Actually Be Doing

Phase 1: Foundation & Architecture (Weeks 1-4) Set up Expo project with TypeScript for maximum code sharing (85-95%) across platforms Design and implement the API client layer to interface with our existing Flask backend Establish Redux Toolkit state management and React Query for API caching Create the component library and design system matching our current UI Implement JWT authentication alongside existing session-based auth Set up CI/CD pipelines for automated testing and deployment Migrate routes one at a time using feature flags (no "big bang" deployment) Start with static pages and authentication flows Progress to complex features: dashboard, listings management, photo upload with drag-and-drop Maintain dual-serving architecture (Flask serves both old and new during transition) Implement real-time features using WebSockets for listing updates Ensure each migrated component maintains feature parity and improves performance Phase 3: Mobile Development (Weeks 13-16) Adapt shared components for optimal mobile UX Implement platform-specific features: push notifications, camera integration, biometric authentication Offline mode with background sync Prepare App Store and Google Play submissions Configure EAS Build for automated mobile deployments Monitor performance metrics and optimize bundle sizes Implement code splitting and lazy loading strategies Maintain

Support gradual rollout to user segments and iterate based on analytics Technical Stack You'll Work With Flask 3.x REST API with 50+ endpoints PostgreSQL with SQLAlchemy ORM Celery task queues with Redis AWS S3 for photo storage Stripe, eBay, OpenAI API integrations Frontend Migration Target: React 18 with TypeScript, React Query, EAS, GitHub Actions Required Experience & Skills Must-Have Technical Skills 5+ years of React production experience with complex state management 2+ years of React Native/Expo experience with apps published to both stores Proven migration experience: led at least 1 production migration from server-rendered to SPA TypeScript proficiency: comfortable with generics, unions, and type inference Testing experience: Jest, React Testing Library, E2E testing Must Have Shipped Production React applications with 50+ components serving 1000+ daily active users At least one React Native/Expo app live in both App Store and Google Play Complex UI features: drag-and-drop, file uploads, real-time updates Push notifications, deep linking, and offline functionality Applications with robust error handling and monitoring Architectural Experience Required Designed component libraries with consistent design systems Implemented code-sharing strategies achieving 70%+ reuse Created gradual migration strategies with feature flags Built offline-first architectures with sync mechanisms Optimized performance for sub-3-second load times The Opportunity Immediate Impact: Your work directly affects thousands of paying customers daily Technical Leadership: Define the frontend architecture for the next 5 years Full Ownership: You'll be the primary architect and implementer Growth Potential: As we scale, build and lead the frontend team Modern Stack: Work with latest tools while solving real business problems What We Offer Competitive Compensation: $95,000 - $120,000 base salary based on experience Performance Bonuses: Quarterly bonuses tied to migration milestones Equity Participation: Stock options in a profitable, growing SaaS Professional Development: Conference attendance, courses, certifications Work-Life Balance: Intense during migration, then sustainable pace Location & Logistics On-site in Joplin, MO is preferred due to migration collaboration needs. See below for local context: Location: About Joplin Low cost of living (housing 40% below national average) 15-minute commute anywhere in town 2.5 hours to Kansas City; 1 hour to Rogers, AR The Team & Culture Founder/CEO, Backend Lead, DevOps Engineer Thousands of Customers: Power sellers managing millions in inventory Ship Early and Often: Daily deployments during migration User-Centric and Data-Driven decisions Pragmatic technology choices for reliability and maintainability Seniority level

Mid-Senior level Employment type

Full-time Job function

Engineering and Information Technology Industries: Software Development Important : Note for Recruiters:

Please do not contact us about this position. We are working directly with candidates only. Unsolicited resumes from recruiting agencies will not be considered. #J-18808-Ljbffr