Senior Backend Engineer (ML)

About this role

COMPANY DESCRIPTION Today, when you go to your doctor and get referred to a specialist, your doctor sends out a referral and tells you, “They’ll be in touch soon.” So you wait. And wait. Sometimes days, weeks, or even months. Why? Because too often providers are overwhelmed with the painstakingly tedious work required to get paid by insurance companies. Powered by proprietary models, Tennr handles the complex paperwork that gets patients through the door and providers paid, helping operators get patients the right care, at the right time, in the right setting. ROLE DESCRIPTION We're looking for a founding Sr. ML Infrastructure Engineer with a strong background in distributed systems and building pipelines that scale. In this role, you'll own the infrastructure that powers Tennr's AI-driven healthcare platform - the training, inference, and data pipelines that let our models handle growing traffic and an expanding product surface. Our ML team builds in-house, proprietary VLMs, LLMs, and other models purpose-built for hard problems in healthcare. You don't need deep ML experience to thrive here - what matters is a strong system design foundation and the interest to grow into the ML-side. If you think in systems, care about reliability, and want to expand into ML infrastructure, this is a rare chance to build foundational systems from the ground up. RESPONSIBILITIES - Architect, build, and scale the cloud infrastructure behind our ML training, inference, and data pipelines. - Design resilient systems for model deployment, evaluation, and monitoring that stay reliable as traffic grows. - Own observability across the stack - logging, metrics, tracing, and alerting. - Troubleshoot production issues and continuously improve performance and efficiency. - Collaborate with ML engineers, backend engineers, and cross-functional teams to integrate models cleanly with data pipelines and products. CANDIDATE QUALIFICATIONS - 4+ years building and scaling infrastructure in production-distributed systems, cloud platforms, or data engineering. - Strong backend software engineering fundamentals, with proficiency in Python and TypeScript. - Hands-on experience with AWS, and PostgreSQL - Solid grasp of observability, reliability, and production incident response. - Comfortable with ambiguity and high ownership; you move fast and drive projects from idea to production in a startup environment. - Interested in growing into ML infrastructure - prior ML ops/infra experience is not required. - Nice to have: exposure to inference engines (vLLM, SGLang, TensorRT), or k8s. WHY TENNR? - Drive Impact: one of our company values is Cowboy, meaning you set the pace. You won’t just talk about things, you’ll get them done. And feel the impact. - Develop Operational Expertise: learn the inner workings of scaling systems, tools, and infrastructure - Innovate with Purpose: we’re not just doing this for fun (although we do have a lot of fun). At Tennr, you’ll join a high-caliber team maniacally focused on reducing patient delays across the U.S. healthcare system. - Build Relationships: collaborate and connect with like-minded, driven individuals in our Hudson Square office 4 days/week - Free lunch! Plus a pantry full of snacks. BENEFITS - Beautiful new office at 345 Hudson Street - Unlimited PTO - 100% paid employee health benefit options - Employer-funded 401(k) match - Competitive parental leave