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.
Responsibilities
- Contribute to all phases of product development, from ideation and prototyping to implementation and iteration
- Design reliable, scalable backend services to support AI-powered features in production
- Build and evolve scalable backend services and APIs that aggregate, enrich, and serve large, complex real estate datasets
- Develop and refine frontend and backend product experiences that make sophisticated data intuitive, trustworthy, and actionable
- Evaluate and benchmark LLM performance across latency, cost, accuracy, and hallucination rates
- Own technical decisions for systems that sit at the center of Mainstay’s SaaS platform and directly influence investor decision-making
- Partner closely with product managers, designers, data science, and data engineering to translate business needs into durable technical solutions
- Improve system reliability, performance, and maintainability as the platform scales
- Modernize and automate legacy real estate workflows by replacing manual analysis with software-driven insights
- Mentor other engineers through code reviews, technical guidance, and shared ownership of team standards
Skills
- 5+ years of experience building and shipping production-grade software in fast-paced and early-stage start up
- Proven, hands-on experience developing and deploying production-ready AI features
- Highly proficient with AI-first thinking and software development best practices
- Strong full-stack engineering skills with a backend-first orientation
- Deep experience designing, building, and operating scalable backend systems, ideally in Python
- Solid frontend experience with React or similar modern frameworks
- Experience working with data-heavy, analytics-driven, or workflow-oriented systems
- Strong technical judgment and the ability to balance speed, correctness, and long-term maintainability
- Clear, thoughtful communication skills for a remote, highly collaborative team
- A proactive, ownership-driven approach to ambiguous problems
Company Overview
Mainstay 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 Sponsorship
Mainstay has a track record of offering H1B sponsorships, with 2 in 2026. Please note that this does not guarantee sponsorship for this specific role.