Thomas Josso

New York City

• Implement a strict TypeScript monorepo with Turborepo and pnpm, integrating an Expo mobile app (Expo Router) and a Next.js web app (App Router) that share a tRPC API, Neon PostgreSQL via Drizzle ORM, and Zod v4, enabling consistent code reuse across platforms and reducing development time
• Use TanStack Query and Zustand in mobile clients, sharing API types from the server through tRPC, which streamlines state management and improves data synchronization performance
• Design authentication with Supabase, supporting Google, Apple, magic-link flows, and optional Upstash Redis for sessions, caching, and rate limiting, providing a secure and flexible login experience that reduces authentication latency
• Apply web CSRF protection, sliding-window rate limits, role-based access control, and audit logging in the API layer, strengthening security and compliance for sensitive operations and minimizing unauthorized-access incidents
• Integrate RevenueCat for native in-app purchases and paywall UI, with server-side access checks and plan-based feature gating, delivering a seamless subscription experience that boosts conversion and retention
• Implement a debate feature using an XState finite-state machine and Inngest asynchronous workflows to handle step timeouts, AI turns, stale-session cleanup, and post-debate analysis, resulting in smoother debate sessions and fewer interruptions
• Develop AI chat with the Vercel AI SDK and OpenAI models, adding streaming responses and Langfuse for prompt management and tracing; a layered response system and token limits keep usage within budget, improving response reliability for users
• Integrate Resend for transactional email, Expo notifications for mobile push, and Vercel Blob storage for user-generated files, which increases delivery reliability and simplifies file handling across platforms
• Combine Sentry for error and performance monitoring, PostHog for web and mobile analytics, and OpenTelemetry metrics exported to Grafana Cloud, providing real-time visibility that speeds issue detection and improves product decisions
• Use GitHub Actions for continuous integration and EAS for mobile releases, with Vitest API tests, enabling faster, reliable deployments and reducing release errors

France

• Developed a viable MVP in the first year and, after missing the target, continued the project as a personal lab to explore new technologies, strengthening full-stack development skills
• Designed and developed an isomorphic mobile and web app from scratch using React Native and Next.js, delivering a cross-platform experience that improved user engagement
• Built a GraphQL API with MySQL and implemented multi-platform CI/CD pipelines, reducing deployment time and increasing release reliability
• Combined market research, user feedback, and input from a fitness coach to design training-focused features, resulting in a feature set that increased user retention

Paris, France

• Delivered features from technical specification drafting to development, testing, and deployment, ensuring seamless integration and improved user satisfaction
• Built automated unit, integration, and regression tests in TypeScript, improving release stability
• Developed with React, Next.js, and React Native to enhance usability and performance, resulting in a more intuitive user experience and faster application load times
• Resolved incidents and managed migrations with minimal impact on users, maintaining high user satisfaction and system reliability
• Implemented new features and bug fixes in a React, Next.js, and GraphQL codebase
• Added Jest and Cypress automated tests, reducing regression issues by 8%
• Improved the release workflow and developer experience, cutting release time by 40%
• Promoted React and TypeScript best practices, raising code quality across the team

Paris, France

• Implemented React Native tech stack for scalable and rapid delivery
• Created a consistent mobile visual identity, supporting €5M fundraising efforts
• Built a lightweight web app for a retailer demo, leading to partnership discussions
• Set up continuous deployment for iOS and Android, speeding up delivery cycles

Paris, France

• Built France's first bet combinator, expanding available betting options and enhancing user engagement
• Updated the interface for the Spanish market launch, improving user experience and accessibility
• Supervised and mentored three interns during their projects, fostering skill development and ensuring project success

Shanghai, China

• Built a WeChat app for a luxury brand to reach the Chinese market, enhancing brand visibility and customer engagement
• Maintained three e-commerce sites and ran targeted ad campaigns for China, increasing site traffic and boosting sales
• Conducted an in-person project wrap-up with the project manager of a major marketing agency, ensuring final approval and client satisfaction
• Provided user training to support adoption and usage, leading to increased user proficiency and reduced support requests