Senior AI-First Full-Stack Engineer

Mainstay Labs Inc.; San Francisco (CA); On-site; USD 180,000 - 240,000; Full time

Job summary

Mainstay Labs Inc. is seeking a senior full-stack software engineer to design, build, and ship AI-powered workflow management tools for our real estate data platform.

You’ll work across the stack, from retrieval pipelines to user-facing product experiences, leveraging Python, TypeScript, and React on AWS. You will contribute across ideation, prototyping, and production, mentor peers, and collaborate with product, data science, and engineering teams to deliver reliable, scalable solutions that

Qualifications

• 5+ years of experience building and shipping production-grade software in fast-paced and early-stage startup.
• Proven, hands-on experience developing and deploying production-ready AI features.
• Strong full-stack engineering skills with a backend-first orientation.
• Solid frontend experience with React or similar modern frameworks.

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

Full-stack

Python

React

AI features

Tools

FastAPI

Django

Airflow

dbt

Snowflake

PostgreSQL

AWS

Terraform

GitHub

Job description

Mainstay Labs Inc. is seeking a senior full-stack software engineer to design, build, and ship AI-powered workflow management tools for our real estate data platform.

You’ll work across the stack, from retrieval pipelines to user-facing product experiences, leveraging Python, TypeScript, and React on AWS. You will contribute across ideation, prototyping, and production, mentor peers, and collaborate with product, data science, and engineering teams to deliver reliable, scalable solutions that