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# Senior Software Engineer, Agents

- **Company:** Ellipsis Health, Inc.
- **Location:** San Francisco, CA, United States
- **Experience:** Expert
- **Salary:** $160,000 - $210,000
- **Contract:** Permanent contract
- **Skills:** Session Initiation Protocols, Python (Programming Language), Software Engineering, Twilio, TypeScript, WebRTC, Workflow Management Systems, Core Voice Platform, Fast Healthcare Interoperability Resources, Retrieval-Augmented Generation, Large Language Models, Electronic Medical Records, Backend, Agentic-AI, Low Latency, Front End Software Development, Invoking Functions
- **Published:** November 8, 2026
- **Apply:** https://www.indeed.com/viewjob?jk=326e9d72edb20be4

## About the Role

* 5+ years of professional software engineering experience, including 1+ year building and shipping LLM-powered applications in production.
 * Strong proficiency in Python and/or TypeScript, comfortable across backend APIs and data, with enough frontend to ship a complete feature.
 * Hands-on experience with prompting, tool use and function calling, RAG, structured outputs, and agent orchestration.
 * Experience designing evals and using data to decide what to fix next.
 * Product sense: you care whether the patient got their appointment booked, not just whether the model metric moved.
 * Clear written and verbal communication with technical and non-technical teammates.

Preferred

 * Voice AI or real-time speech experience, including STT, TTS, voice activity detection and turn-taking, and telephony (Twilio, SIP, WebRTC).
 * Fine-tuning or post-training experience with open or hosted models.
 * Experience in healthcare or another regulated environment, including HIPAA, EHR, and FHIR.
 * Experience with workflow orchestration (e.g., Temporal).
 * Familiarity with LLM observability and tracing tools.

## Description

You'll work directly with our SVP of Engineering and engineering leads, alongside product, clinical, and customer teams, on a small team where your work reaches production fast. The ideal candidate is a hands-on builder and fast learner who is comfortable with ambiguity, communicates clearly with engineers, nurses, and health system executives alike, and is motivated by making healthcare work better for patients., * Design, build, and ship AI agents end to end, including conversation flows, prompts, tool and function calling, retrieval, memory, and the backend services agents depend on.

 * Build evaluation systems (offline test suites, simulated conversations, human review loops, and production monitoring) so we know an agent is good before and after it ships.
 * Improve instruction following, tool-calling reliability, latency, and cost across our LLM and speech stack.
 * Help design and build our next-generation voice agent platform, choosing the right models and architecture for each task based on quality, latency, and cost.
 * Partner with clinical, product, and customer teams to turn workflows like scheduling, refills, billing, and post-discharge check-ins into reliable agent behavior.
 * Dig into real conversations and failure cases, and close the loop with prompt, tool, model, or product changes.
 * Build internal tools to observe, monitor, and analyze agent behavior at scale to identify common failure modes and patterns.
 * Track what's new in models and tooling, and bring the useful parts into production quickly.