Senior Software Engineer — AI & LLM Systems

Arcadia; San Francisco (CA); On-site; USD 180,000 - 240,000; Full time

Job summary

Arcadia, a high-growth startup, is hiring a Senior Software Engineer to join the founding team. You will own full stack architecture across frontend and backend, working with TypeScript/React on the frontend and Python on the backend, directly with LLMs to measure model behavior.

You'll build evaluation frameworks, architect AI agent workflows, and influence product features and roadmaps in a fast-paced, autonomous environment.

Qualifications

• Strong full stack experience in production environments.
• Hands-on with LLMs, evals, RAG, or applied AI product work.

Responsibilities

• Own full stack architecture decisions from day one, spanning frontend to backend.
• Design and build systems that evaluate and quantify LLM perception of structured and unstructured data.
• Build and orchestrate agentic workflows for automated evaluation, data processing, and model behavior analysis.
• Work directly with LLMs and model outputs to build novel measurement and evaluation frameworks.
• Ship product end to end, from data pipelines to user-facing interfaces.

Skills

TypeScript

React

Python

Full stack

LLMs

Job description

Arcadia, a high-growth startup, is hiring a Senior Software Engineer to join the founding team. You will own full stack architecture across frontend and backend, working with TypeScript/React on the frontend and Python on the backend, directly with LLMs to measure model behavior.

You'll build evaluation frameworks, architect AI agent workflows, and influence product features and roadmaps in a fast-paced, autonomous environment.