Senior Software Engineer, Agents

FERMÀT is the AI native commerce platform that optimizes shopping experiences, leading to best-in-class shopper engagement and conversion. We help brands transform clicks into conversions with dynamic, personalized shopping experiences-built and optimized in minutes.

Backed by VMG, Bain Capital Ventures, Greylock, QED, and named The Information's #1 commerce startup, we're a 70+ person team based in SF, Austin, NYC, and Bangalore. As a fast-growing Series B company, we're building the infrastructure for the future of online retail-and we're just getting started.

About the Role :

We're searching for a productminded Software Engineer to help build out Pierre , FERMÀT's AI Agent, into a productiongrade intelligence engine that powers personalization, automation, and operational insights across our commerce platform. You will design and build LLMpowered features endtoend : orchestration (tools / agents / functioncalling), retrieval, evaluations and productionization (APIs, observability, cost / latency). If you love turning ambiguous problems into shipped experiences-and you have experience taking AI products to market in the last 12 to 18 months, this role is for you.

What You'll Work On :

• Take AI products to market : prototype quickly, instrument, A / B test, and iterate based on quality, conversion impact, latency, and cost.
• Own LLM orchestration : multi-agent systems, tool use, functioncalling, structured outputs, routing, context windows, retrieval and evals.
• Build evaluation & observability : golden datasets, automated evals, prompt / version management and monitoring.
• Productionize reliably : scalable APIs / services, workers / queues, caching and provider failover. Optimize performance while keeping costs reasonable.
• Data foundations : integrate firstparty events and catalog data; respect data contracts.
• Vendor strategy : evaluate and integrate multiple model providers (e.g., OpenAI, Anthropic, Google) while tracking quality, cost, and reliability.
• Raise the bar : document best practices, lead design reviews, and mentor engineers on AI patterns.

What We're Looking For :

Nice to have

Benefits

US : 401(k) plan with 4% matching