Senior / Staff Backend Engineer

About AscertainAscertain is a healthcare technology company based in New York City, building AI agents to automate the administrative work that burdens care teams.Our platform combines structured and unstructured data with clinical logic to streamline workflows in care management and revenue cycle — eliminating tedious manual tasks like prior authorizations, referrals, and documentation so clinicians and support staff can focus on patients.We're already live in production with major health systems and have been trusted to automate high-impact workflows in complex environments.Ascertain's backers include Northwell Health, New York's largest health system, and Deerfield Management, a leading healthcare investment firm.These partnerships give us deep roots in care delivery and the long-term support to build with rigor.We're on a mission to restore time, trust, and focus to the people who keep healthcare running.Our work is urgent — not because of startup timelines, but because our customers rely on us to drive financial resilience and operational clarity in a system under strain.About the JobAs a Backend Software Engineer at Ascertain, you will build scalable, robust infrastructure and backend services that power Ascertain's healthcare AI platform.You'll take the lead in defining best practices around our infrastructure, security, CI/CD pipelines, and cloud hosting strategy.As one of our earliest engineering hires, you'll have significant ownership in shaping both technical architecture and our engineering culture.You'll work closely with product and engineering teams to ensure our platform remains secure, performant, reliable, and scalable.While your primary focus is backend and infrastructure, our team is small—engineers are empowered to work across the stack when needed to fully own a feature.Ascertain is headquartered in New York City, where part of our engineering team works in person.We also hire engineers across the U.S. and internationally for fully remote roles, and we operate with a culture of high autonomy, shared accountability, and deep respect for the people who use what we build.What You'll Do:Design and develop scalable back-end services using Python and FastAPI.Understand infrastructure managed with Kubernetes, Docker, and Terraform.Work closely with product managers, designers, and other engineers to define technical requirements and translate them into robust software solutions.Participate in code reviews, providing constructive feedback and ensuring high-quality code standards.Mentor junior developers and contribute to fostering a collaborative engineering culture.Contribute to improving software development processes and best practices.What You'll Need:7+ years of experience in back-end development using Python and FastAPI.Strong backend expertise, especially Python-based APIs (ideally FastAPI), relational databases, and caching systems.Familiarity with modern DevOps and infrastructure tools (Docker, Kubernetes, Terraform) and experience with cloud architecture and CI/CD processes.What You'll Bring to the Table:You have a security-minded approach to software design, with experience in regulated environments a plus.Experience in ambiguous startup environments, proactively take ownership, and communicate clearly across teams.Excitement (not just willingness) to dive into new technologies, learn quickly, and step beyond your comfort zone in a rapidly evolving environment.Benefits & Perks:Cutting-edge technology: Work directly with the latest advancements in generative AI and automation, tackling challenging problems that meaningfully impact healthcare.Ownership & growth: You'll join Ascertain at a pivotal early stage, shaping our products, technical direction, and culture, with significant opportunities for career advancement.Collaborative team: Join a talented, passionate, and supportive team with backgrounds from top tech companies and clinical institutions.Competitive compensation: We offer competitive salary, meaningful equity, comprehensive health insurance, and more.Why Ascertain?Make a real difference: Your work will directly impact healthcare organizations and improve patient care.Join Ascertain in transforming healthcare with AI