Fullstack Software Engineer (AI-Native)

Join Proton, an AI-native startup, as a Senior Fullstack Engineer. In this generalist role, you'll work across the entire stack, collaborating with PMs, designers, and other engineers to build and deploy features that directly impact distributors. You'll also have the opportunity to work directly with customers, supporting onboarding and troubleshooting integrations. This role requires strong fundamentals in software engineering, a startup mindset, and experience with distribution ERPs. Enjoy benefits such as company stock options, unlimited PTO, and a flexible schedule.

• Assurer la livraison de bout en bout des fonctionnalités, de la définition des tickets au déploiement, à la surveillance et à l'itération.
• Utiliser des agents de codage AI (Claude Code et similaires) à un niveau élevé : définir le travail, structurer le contexte, exécuter plusieurs agents en parallèle.
• Collaborer dans un modèle d'équipe avec des chefs de produit, des designers et des ingénieurs ; participer aux sprints de 2 semaines, aux réunions debout, aux révisions de code.
• Strong fundamentals. You understand what the code is doing and why. You can read a stack trace, reason about a query plan, debug a race condition, and tell when an agent is wrong. We are explicitly not hiring "vibe coders" who depend on AI to compensate for missing fundamentals — AI amplifies seniority, it doesn't replace it
• Ownership and judgment. You take features from idea to production and exercise good taste on what to build, what to cut, and when AI output isn't good enough
• Daily, hands-on use of agentic dev tools. Claude Code, Cursor agent mode, Codex, or equivalent — used to ship real features, not just autocomplete. You can talk concretely about how you structure prompts, manage context, parallelize agents, and verify their output
• Startup mindset. Pragmatic, fast, biased to ship, comfortable with ambiguity, close to users
• 5+ years as a software engineer with real, demonstrable fullstack delivery — production systems, real users, real ownership. Resume-level hands-on experience, not LLM-generated portfolios
• Generalist instinct. You're comfortable jumping between Vue, Python, SQL, infra, and integrations. You don't wait for someone else to take the layer you're "not assigned to."
• Strong communication. You can explain technical decisions to PMs, designers, and customers — in writing and in person
• Database and systems chops. You design efficient schemas and queries, understand indexing and tradeoffs, and can reason about distributed-system failure modes
• Experience building integrations with distribution ERPs (Epicor Eclipse, P21, or similar) — ingesting orders, products, customers, pricing; reconciling messy real-world data. Bonus if you've done this in a customer-facing or implementation context
• Experience building or integrating with agentic products — MCP servers, tool-using agents, agent frameworks, evals, prompt/context engineering at the system level
• Prior experience at an early-stage SaaS startup