Principal Software Engineer - Agent AI Platform

Teams across Arcadia already put agents to work enabling clients' clinical, analytics, and operations teams. We use them heavily for our own work, too. Much of the platform foundation is in place. Now it has to handle longer-running workflows, client-facing agents, and PHI at scale.

You'll join the team that owns the platform underneath these agent workflows. This isn't a solo mandate. Your influence comes from what you ship and what other teams build on top of it.

Engineers at Arcadia own outcomes end to end: the problem, the design, the code, the rollout, and the result in production. We build alongside AI without handing it our judgment; our automation is governed and transparent, built to strengthen human expertise, not replace it. We have few layers, high agency, deep ownership. We adopt new tools and practices quickly, which lets us move faster than many startups while keeping the discipline a regulated environment demands.

Our agent platform sits on top of governed access to AWS-based petabyte-scale lakehouse data with open table formats, distributed Spark processing, and Kubernetes services. The current implementation has an OSS agent harness and a gateway/router across model providers, all built on a third-party agent framework.

Arcadia product teams should be able to spin up an agent quickly, ship it with confidence, and evolve it over time safely and cost-effectively. The platform provides the building blocks: persistence, workflows, memory, and identity-aware, compliant connectivity to tools. The platform also takes care of the quality attributes: caching, compaction, evals, guardrails, observability, resiliency, and safe handling of PHI.

Teams adopt it because it's the fastest safe path, not because they're told to. You treat it as a product and can show the impact in numbers.

Next: customers bring their own agents to Arcadia, and eventually assemble them from our building blocks.

What You'll Be Doing

• Evolve and run our agent platform for both internal and client-facing use cases: the runtime, SDKs, templates, and paved paths that let teams ship agents on Arcadia's data. You write a meaningful share of the code.
• Stand up and harden the infrastructure underneath it: IaC, network topology, security controls, and the operational tooling that keeps it running, in close partnership with SRE.
• Make quality attributes platform defaults, not per-team projects: evaluation harnesses and regression gates, guardrails and policy enforcement, tracing and telemetry, and resiliency patterns for model, tool, and data failures, plus the inevitable provider churn.
• Design for a regulated industry: PHI isolation, least-privilege identity for agents, audit trails, and human review.
• Run the platform as an internal product: work with the teams building on it every week, and measure adoption and developer experience.
• Partner with domain teams on their hardest agent use cases, and turn what you learn into platform capability.
• Own it in production: SLOs, on-call, incident response, and postmortems.
• Set the technical bar for how engineers build with AI at Arcadia, and coach Senior Engineers through design partnership and review. Their trajectory is part of your impact.

What You'll Bring

• Platforms you've built and run that other engineering teams adopted, from ambiguous beginnings through years of operation, with results you can show.
• Deep foundations in cloud-native distributed systems, data infrastructure, and service architecture. You reason from first principles.
• Hands-on infrastructure depth: IaC, cloud, security architecture, and running production systems. You can go deep with SRE, not just hand work off to them.
• Current, hands-on production coding, and the desire to keep doing it.
• Passion for developer experience (DevEx/DevProd) as a discipline.
• Writing clear enough to set standards beyond your own work, and influence that comes from credibility, not title.
• No healthcare background required. We hire builders from fintech, infrastructure, and consumer scale, and teach the domain.

Would Love for You to Have

• Scars from production LLM/agent deployments beyond glossy demos (but we won't ask for 20 years of LLM experience).
• Pragmatism about the LLM ecosystem: excited by it, not distracted by it.
• Regulated-data experience (HIPAA, PHI, SOC 2 or HITRUST environments).
• A public voice through talks, writing, or open source.

What You'll Get

The opportunity to own one of Arcadia's most consequential platform domains and to set its direction for years.
Direct influence on how Arcadia's engineering org adopts AI; your tooling, patterns, and standards become examples others build on.
Remote-first across the US, with in-person hubs growing in Boston, DC, and NYC.
A flexible culture with personality and heart, named a Built In 2026 Best Place to Work.
Work that shows up in patients' lives.