Senior Product Engineer, Treasury (Elixir)

Job description

**This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Product Engineer, Treasury (Elixir) based in the United States.** Join an innovative engineering team building an AI-powered finance platform that transforms how enterprises manage payments, treasury, and financial operations. As a Senior Product Engineer, you will design and scale the core services behind a treasury platform handling billions in transaction volume. Your work will help enable next-generation financial workflows, including AI agents that initiate corporate expenses, manage travel, and use payment cards. Working closely with founders and a small, senior team across engineering, product, treasury, and data/AI, you will shape product direction and technical architecture. This hands-on role combines deep Elixir expertise with end-to-end product ownership, from defining requirements and building interfaces to operating reliable production systems. The position is fully remote for US-based candidates working Eastern Time hours, with significant autonomy and opportunities to influence the future of financial technology. ### Accountabilities: As a Senior Product Engineer, you will take ownership of critical treasury product capabilities, building reliable backend services and complete user-facing features. You will contribute to technical strategy, establish strong engineering practices, and help deliver resilient systems that support increasingly sophisticated financial workflows. - Design, build, deploy, and operate Elixir and Phoenix services, including APIs, data pipelines, and asynchronous processing systems. - Own product features throughout the entire software development lifecycle, from problem discovery and requirements definition to backend implementation, frontend delivery, and production operations. - Develop and scale core treasury services that support high-volume financial transactions and emerging AI-driven spending workflows. - Build and improve infrastructure that enables AI agents to initiate corporate expenses and travel, as well as create and use payment cards. - Prioritize reliability across critical Tier 0 and Tier 1 systems through robust observability, monitoring, and operational practices. - Collaborate directly with company founders and senior colleagues across treasury, product, engineering, and data/AI to shape product direction and technical decisions. - Use AI-assisted development tools, particularly Claude Code, to improve engineering productivity and support high-quality implementation. - Help establish and refine architectural standards, engineering workflows, development practices, and code review processes. - Contribute to a collaborative engineering culture focused on end-to-end ownership, maintainability, and dependable production systems. **Requirements:** The ideal candidate is an experienced product-minded engineer with strong production experience in Elixir and Phoenix, a solid understanding of distributed systems, and the ability to deliver complete features independently. You should combine technical depth with clear communication, sound product judgment, and practical experience using AI-assisted development tools. - Be based in the United States and able to work Eastern Time hours in close collaboration with the treasury team. - Have at least 5 years of professional software engineering experience. - Demonstrate strong hands-on experience developing and operating production applications with Elixir and Phoenix. - Be comfortable owning features end-to-end, from product framing and requirements through backend services, frontend implementation, and production support. - Have a solid understanding of distributed systems, concurrency, and asynchronous processing. - Possess strong PostgreSQL skills and practical experience with cloud infrastructure, Kubernetes, and CI/CD pipelines. - Demonstrate fluent, day-to-day use of AI coding tools, particularly Claude Code, in real software development workflows. - Communicate clearly with both technical and non-technical stakeholders. - Have fluent English communication skills. **Nice-to-have qualifications:** - Experience with Python or other backend programming languages. - Background in payments, treasury, fintech, or related financial technology domains. - Familiarity with event-driven architectures, message queues, and workflow orchestration. - Exposure to AI- or machine learning-powered products. **Benefits:** - **Competitive compensation:** Salary package designed to reflect experience and expertise. - **Meaningful equity:** Opportunity to participate in the company's growth and success. - **AI tooling budget:** Extensive resources for AI-assisted development and engineering productivity. - **Generous paid time off:** Support for rest, personal commitments, and work-life balance. - **Remote-first flexibility:** Fully remote work with a flexible schedule, aligned with Eastern Time collaboration. - **Health and wellness:** Comprehensive health coverage and wellness benefits. - **Autonomy and ownership:** Direct influence over product direction, architecture, and engineering decisions. - **Innovative technical environment:** Opportunity to build advanced payment and treasury infrastructure, including AI-driven financial workflows. - **Inclusive culture:** A commitment to diversity of thought, culture, and background, with equal employment opportunities.