[Remote] Senior Full-Stack Software Engineer

Note: The job is a remote job and is open to candidates in USA. Mainstay is the leading market intelligence platform for the single family rental industry, leveraging AI to provide clarity in complex data. The role of Senior Full-Stack Software Engineer involves designing, building, and shipping AI-powered workflow management systems and tools that support operational efficiency and scalability.ResponsibilitiesContribute to all phases of product development, from ideation and prototyping to implementation and iterationDesign reliable, scalable backend services to support AI-powered features in productionBuild and evolve scalable backend services and APIs that aggregate, enrich, and serve large, complex real estate datasetsDevelop and refine frontend and backend product experiences that make sophisticated data intuitive, trustworthy, and actionableEvaluate and benchmark LLM performance across latency, cost, accuracy, and hallucination ratesOwn technical decisions for systems that sit at the center of Mainstay’s SaaS platform and directly influence investor decision-makingPartner closely with product managers, designers, data science, and data engineering to translate business needs into durable technical solutionsImprove system reliability, performance, and maintainability as the platform scalesModernize and automate legacy real estate workflows by replacing manual analysis with software-driven insightsMentor other engineers through code reviews, technical guidance, and shared ownership of team standardsSkills5+ years of experience building and shipping production-grade software in fast-paced and early-stage start upProven, hands-on experience developing and deploying production-ready AI featuresHighly proficient with AI-first thinking and software development best practicesStrong full-stack engineering skills with a backend-first orientationDeep experience designing, building, and operating scalable backend systems, ideally in PythonSolid frontend experience with React or similar modern frameworksExperience working with data-heavy, analytics-driven, or workflow-oriented systemsStrong technical judgment and the ability to balance speed, correctness, and long-term maintainabilityClear, thoughtful communication skills for a remote, highly collaborative teamA proactive, ownership-driven approach to ambiguous problemsCompany OverviewMainstay operates a market intelligence and transaction platform to unlock single-family rental opportunities. It was founded in 2020, and is headquartered in San Francisco, California, USA, with a workforce of 51-200 employees. Its website is https://www.mainstay.io/.Company H1B SponsorshipMainstay has a track record of offering H1B sponsorships, with 2 in 2026. Please note that this does not guarantee sponsorship for this specific role.