Software Engineer

About Cobalt

Cobalt is the infrastructure layer that makes healthcare AI possible. Dozens of high-growth companies rely on us as core infrastructure. We’re the reason their products can connect to healthcare systems at all. When they need to move fast, we’re the team they call.

We’ve built this with a lean, elite team that punches way above its weight. No bloat, no layers, no passengers. Every person here has outsized impact, and we intend to keep it that way as we scale. If you want to do the best work of your career at a company that’s growing fast and building something that actually matters, keep reading.

About the role

Our API is the backbone of how the fastest-growing AI health tech companies connect to EHRs. When it breaks, their products break. When we ship, they ship. That's the weight of this role, and why we only hire engineers who thrive under it.

You'll own systems end-to-end across our platform: backend services, AI-powered data pipelines, integration tooling, and everything in between. We're a small engineering team shipping fast against hard problems — messy healthcare data, real-time pipelines, and systems built in the '90s. You'll write code that thousands of clinicians depend on every day, and you'll ship it this week.

What you’ll do

• ›Design, build, and ship production features across our API platform
• ›Build reliable integrations with complex, legacy healthcare systems
• ›Apply AI where it solves real problems: data mapping, integration onboarding, automation across the stack
• ›Own the full lifecycle: architecture, implementation, testing, deployment, monitoring
• ›Work directly with customers to understand requirements and debug complex issues

What we’re looking for

• ›3+ years of professional software engineering experience
• ›You've built and shipped backend systems that real people depend on
• ›AI-native. You use AI tools daily and have strong intuition for when to use an LLM, a classical model, or a simple rule
• ›Comfortable working in ambiguity. You figure things out, not wait for a spec
• ›Strong product sense — you care about what gets built, not just how

Nice to have

• +Background in developer tools, APIs, or infrastructure products
• +Experience taking AI systems from prototype to production
• +Healthcare industry exposure