Senior Product Engineer, Treasury (Elixir)

Senior Product Engineer, Treasury (Elixir) Remote — US-based, working EST hours About Solstice Analytics Solstice Analytics is building the autonomous finance platform for the modern enterprise. We use AI to automate accounts payable and treasury workflows so finance teams operate with more speed, accuracy, and insight — today processing hundreds of millions of invoices a year. We're venture-backed, with teams in Miami, Raleigh, and Oslo. The Role We're looking for a senior engineer with deep Elixir experience to build and scale the core services behind our treasury platform (moves billions in transaction volume). Increasingly that means agent-driven spend: AI agents that initiate corporate expense and travel, plus the infrastructure for them to create and use payment cards — some of the most forward-looking work at the company. Elixir is the anchor, but we want someone who thinks beyond the backend: an engineer with organized product thinking who can own a problem end-to-end across the SDLC — from shaping the requirement, to the backend service, to the front-end it ships behind, to running it in production. You'll work directly with the founders on product direction, alongside a small, senior team across treasury, product, and data/AI. What you'll do Design, build, and operate Elixir/Phoenix services — APIs, data pipelines, and async processing. Own features end-to-end, from product framing through the front-end needed to ship. Treat reliability as first-class on Tier 0/1 systems: observability, monitoring, and operational rigor. Use AI-assisted tools (esp. Claude Code ) and help shape architecture, practices, and code review. What we're looking for US-based and able to work EST hours — you'll be embedded with an EST-based treasury team. 5+ years of professional experience, with strong production Elixir and Phoenix . Ships features end-to-end — product framing through front-end — without a handoff. Solid grounding in distributed systems, concurrency, and async processing. Strong PostgreSQL ; hands-on with cloud infrastructure, Kubernetes, and CI/CD. Demonstrated, fluent use of AI coding tools (esp. Claude Code ) in real day-to-day work. Clear communicator across technical and non-technical teams; fluent English. Nice to have Python or other backend languages. Payments, treasury, or fintech domain experience. Event-driven architectures, message queues, workflow orchestration. Exposure to AI/ML-powered products. What we offer Competitive compensation, meaningful equity and an extensive AI tooling budget. Generous PTO and a remote-first, flexible schedule. Comprehensive health and wellness benefits. Real autonomy and ownership — a direct hand in where payments and treasury go. Acceptance and inclusion for everyone is at the heart of our company. We strive for diversity of thought, culture and background, which connects the entire Solstice Analytics community. We are proud to be an Equal Opportunity Employer.