/ Curriculum Vitae

Thomas Josso

FULL-STACK · TECHNICAL LEAD · WEB & MOBILE

Download Engineering résumé (PDF)

/ 01 · Profile

Profile

Senior full-stack engineer and technical lead. Eight years building for early-stage startups and products serving millions, across Paris, Shanghai, and New York. Architecting scalable systems, secure authentication, and CI/CD pipelines across backend, frontend, and AI integration. Leading collaborative, multicultural teams. The range is the asset.

/ 02 · Experience

Experience

Technical Lead (Founder) · rixAI

Mar 2026 – Present

New York City

  • Implement a strict TypeScript monorepo with Turborepo and pnpm: an Expo mobile app (Expo Router) and a Next.js web app (App Router) sharing a tRPC API, Neon PostgreSQL via Drizzle ORM, and Zod v4, for consistent code reuse across web and mobile
  • Use TanStack Query and Zustand on mobile, sharing API types from the server through tRPC for end-to-end type safety
  • Design authentication with Supabase (Google, Apple, magic-link), with Upstash Redis for sessions, caching, and rate limiting
  • Apply CSRF protection, sliding-window rate limits, role-based access control (RBAC), and audit logging in the API layer
  • Integrate RevenueCat for native in-app purchases and paywall UI, with server-side access checks and plan-based feature gating
  • Implement a debate feature with an XState finite-state machine and Inngest async workflows handling step timeouts, AI turns, stale-session cleanup, and post-debate analysis
  • Develop AI chat with the Vercel AI SDK and OpenAI, with streaming responses and Langfuse for prompt management and tracing; layered fallbacks and token limits keep usage within budget
  • Integrate Resend for transactional email, Expo push notifications, and Vercel Blob storage for user-generated files
  • Combine Sentry for error and performance monitoring, PostHog for web and mobile analytics, and OpenTelemetry metrics exported to Grafana Cloud for real-time visibility
  • Use GitHub Actions for CI and EAS for mobile releases, with Vitest API tests

Technical Lead (Founder) · Fitness App

Jul 2023 – Apr 2025

France

  • Developed a viable MVP in the first year, then kept the project as a personal lab to explore new technologies
  • Designed and built an isomorphic mobile and web app from scratch with React Native and Next.js
  • Built a GraphQL API with MySQL and multi-platform CI/CD pipelines, cutting deployment time
  • Combined market research, user feedback, and input from a fitness coach to design training features that improved retention

Product Engineer · previously Software Engineer · Amblea

Jan 2020 – Jul 2023

Paris, France

  • Delivered features end to end in a React, Next.js, and GraphQL codebase, from technical spec through development, testing, and deployment
  • Built across React, Next.js, and React Native for faster load times and a more intuitive UX
  • Added Jest and Cypress automated tests in TypeScript, cutting regressions by 8%
  • Improved the release workflow and developer experience, cutting release time by 40%
  • Resolved incidents and ran migrations with minimal impact on users
  • Promoted React and TypeScript best practices, raising code quality across the team

Frontend Engineer · Boxy

Jul 2019 – Dec 2019

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

Frontend Engineer · Winamax

Jul 2018 – Jun 2019

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

Full Stack Developer · 31Ten

Sep 2016 – Jan 2017

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

/ 03 · Skills

Skills

PROGRAMMING LANGUAGES

TypeScriptJavaScriptSQLHTMLCSS

FRONTEND

ReactNext.jsVercelReact NativeTailwind CSSExpoExpo RouterZustandTanStack QueryServer Side Rendering

BACKEND

Node.jstRPCRESTGraphQLPostgreSQLMySQLDrizzleNeonSupabaseRedisZodInngestXStateOpenAILangfuseMem0RevenueCatResend

TESTING

VitestJestCypress

DEVOPS & TOOLS

CI/CDGitHub ActionsDockerAWSVercelEASGitSentryDatadogPostHogOpenTelemetryGrafanaKnip

PRACTICES

MonorepoProduct DevelopmentUX/UI DesignSEOCode ReviewProduct ManagementMarket AnalysisBusiness StrategyUser FeedbackCross-cultural DevelopmentEnd-user TrainingEntrepreneurial MindsetRole-Based Access Control (RBAC)CSRFCircuit Breaker

/ 04 · Education

Education & Languages

2013 – 2018

EPITA

Engineering Degree, Computer Science · Grandes Écoles

Paris, France

Languages

French (Native)

English (Fluent)