Senior Full-Stack Engineer - High-Growth AI SaaS Startup
SoMa, San Francisco, CA | Full-Time | Onsite
Salary: $200K-$300K + Meaningful Equity (1%+)
Join an early-stage AI SaaS startup building an application builder that empowers business users to create custom applications where humans and AI collaborate seamlessly across enterprise workflows. You'll play a pivotal role in shaping core architecture, product development, and first production deployments, working directly with the founder and early team.
About the Role
We're seeking a Senior Full-Stack Engineer to lead product development and own major product surfaces across frontend, backend, and integration layers. This is a high-impact role where you'll directly influence product direction and help build the foundation for Lumena's platform.
What You'll Do
• Design and build the core application builder - the orchestration layer connecting workflows, agents, and front-end views.
• Develop and scale Lumena's TypeScript-based backend and modern frontend stack (React + Tailwind).
• Build dynamic frontend interfaces for dashboards, forms, and human-AI workflows.
• Collaborate with the applied engineering team to integrate automation and intelligence across systems.
• Shape and maintain the integration layer connecting REST APIs, SQL sources, and third-party systems.
• Define and enforce best practices for product engineering, architecture, and developer experience as the company scales.
Who You Are (Must-Haves)
• 5-15 years of professional software engineering experience in full-stack development.
• Prior experience working in early-stage startups or high-growth environments.
• Strong proficiency with TypeScript, Node.js, and modern frontend frameworks (React, Tailwind).
• Experience designing complex architectures, asynchronous workflows, and integrations.
• Excellent problem-solving, collaboration, and communication skills.
Nice-to-Haves
• Experience building or integrating AI / LLM-powered applications.
• Familiarity with orchestration/workflow frameworks such as Temporal.
• Exposure to cloud platforms (AWS/GCP/Azure), containerisation, Kubernetes, and CI/CD pipelines.
• Experience with enterprise-grade concerns: secure hosting (VPCs), observability, identity & compliance.
Why Join?
• Competitive salary: $200K-$300K + meaningful equity (1%+) in an early-stage company.
• Work directly with experienced founders and influence the product roadmap.
• Shape the architecture and direction of a high-impact platform powering first production deployments.
• Be part of a small, agile, highly motivated team at the forefront of AI and enterprise applications.
