Senior Full-Stack Engineer — AI Platform (On-site + Equity)

Arcus Search; San Francisco (CA); On-site; USD 180,000 - 280,000; Full time

Job summary

Arcus Search is hiring a Senior Full Stack Engineer to own technical decisions and shape the engineering foundations of an early-stage AI startup. You will work across the full stack, building production-grade applications that integrate LLMs into enterprise workflows and collaborate with a small, ambitious team.

You’ll contribute from architecture to deployment, engaging with customers to understand challenges and iterate the product.

Qualifications

• 5+ years of software engineering experience with full-stack focus.
• Experience integrating LLMs into production apps.
• Backend in Go or other typed language plus Python.
• Frontend with React and TypeScript; PostgreSQL knowledge.
• Understanding of LLM development patterns: orchestration, tool calling, context management.
• Experience owning significant engineering projects and decisions.
• Product-minded approach with balance of quality and delivery speed.
• Strong communication and incorporating customer feedback into product development.
• Experience with agentic AI or multi-step workflows.
• Prior startup or founding engineer experience.
• Experience in large tech environments with high autonomy.
• Familiarity with Terraform, Docker, and GCP.

Responsibilities

• Design, build and ship production features across frontend, backend and AI integration layers.
• Develop LLM-powered applications with orchestration and tool calling.
• Build reliable backend services and APIs using Go, Python and PostgreSQL.
• Take ownership of projects end-to-end, guiding architecture and delivery.
• Work with customers to understand challenges and iterate based on feedback.
• Help establish engineering practices and technical foundations as the company grows.

Skills

Full-stack development

LLM integration

Go

Python

React

TypeScript

PostgreSQL

LLM patterns

Project ownership

Product-minded

Communication

Agentic AI

Startup experience

Large tech experience

Infrastructure as code

Tools

Terraform

Docker

GCP

Job description

Arcus Search is hiring a Senior Full Stack Engineer to own technical decisions and shape the engineering foundations of an early-stage AI startup. You will work across the full stack, building production-grade applications that integrate LLMs into enterprise workflows and collaborate with a small, ambitious team.

You’ll contribute from architecture to deployment, engaging with customers to understand challenges and iterate the product.