AI UI ENGINEER

Rational Exponent is seeking an experienced full-stack Software Engineer to help deliver the future of trustworthy, reliable AI applications for large, regulated entities.

THE ROLE

You will work as a full-stack engineer on the core Reagent product, embedded in a small delivery team alongside a product representative, tech lead, DevOps, and QA. Your job is to take stories from refinement to “done” — end-to-end, across the full stack, with ownership of the full lifecycle.

We work in thin vertical slices. That means getting to working, demonstrable software as fast as possible — not building layers and assembling them at the end. If you instinctively want to prove E2E integration first and defer the edge cases, you’ll thrive here.

We use AI tooling — Claude Code and others — as a primary development workflow, not an occasional assistant. We expect you to work the same way and to raise the bar for the people around you.

WHAT YOU’LL LOVE

• Genuinely hard problems: trust, governance, and evaluation of AI in regulated industries — a space most companies aren’t solving yet
• A team small enough that your work is visible and your opinions shape direction
• Real autonomy: you own your tickets end-to-end
• An AI-native environment where good use of tooling multiplies your impact
• The chance to learn and use leading-edge tools and techniques, without excessive bureaucracy

WHAT TO EXPECT

• We work as a team, and everyone owns the delivery outcome. We’ll support you when you’re blocked — but the expectation is that you drive your stories to “done” and keep things moving
• The backlog moves fast, and delivery cadence is continuous
• This is a genuinely full-stack role. We expect contribution across frontend and backend — AI tooling has made this more achievable than ever, and we invest in helping engineers grow across the stack
• We value engineers who raise the bar — sharing best practice, contributing to code quality, and helping the team grow

WHAT WE’RE LOOKING FOR

• Proven, demonstrable delivery focus. We want to hear concrete examples — the things you drove, the decisions you owned, the outcomes you delivered, including times you took something to “done” on your own initiative
• AI-native development workflow. You use AI tooling to move faster, and you know how to structure your work to get the best out of it
• Full-stack fluency. Frontend and backend. You pick up whatever the story requires
• Thin-slice thinking. You decompose work into the smallest thing that proves E2E integration. You don’t defer the hard integration problems to the end
• Integration testing discipline. You write integration tests that verify real system behaviour across layers — not mocked-out proxies that pass while production breaks. You know the difference between a test suite that gives you genuine confidence and one that just gives you green lights
• Jira hygiene and ticket ownership. Stories move because you move them — from refinement through QA to “done”
• Fast learner with strong fundamentals. We care more about how you think and how you work than how many years you’ve been doing it
• Clear, proactive async communicator. We are 100% remote. Silence is a blocker. You surface issues early, keep the team informed without being prompted, and communicate with enough clarity that your intent is never in doubt in a Jira comment or Teams message
• Confident enough to raise the bar. You model best practice and you’re not shy about it

TECH STACK

This is what we build with. You’re expected to work across it:

Core foundations: Strong Python and React/TypeScript are essential starting points.

Our stack: Python, FastAPI, LangChain, LlamaIndex, MLflow, Svelte/SvelteKit/TypeScript, MongoDB, Qdrant, Kubernetes, Terraform, AWS (EKS, Lambda, S3, Bedrock), Azure Cognitive Services, REST, GraphQL, OpenAI and HuggingFace APIs.

Our frontend is built in Svelte/SvelteKit. Strong React/TypeScript engineers pick it up quickly — AI tooling makes the transition straightforward.

ABOUT RATIONAL EXPONENT

Rational Exponent is a new company with an experienced team with a track record of successfully building, scaling, and exiting enterprise software and services companies with a particular focus on finance, banking, capital markets, healthcare, and other highly regulated industries. Our mission is to provide the tools and controls that will allow complex, regulated entities to confidently deploy applications based on state-of-the-art foundation model AI. We develop systems and frameworks to allow our customers to create trustworthy cognitive applications that control risks, evidence compliance, and deliver business value.

COMPREHENSIVE BENEFITS THAT SUPPORT YOU AND YOUR FAMILY

We provide a competitive benefits package designed to support your health, financial future, and work-life balance including multiple national medical, dental (with a $0 employee option), and vision plans with company premium contributions, tax-advantaged accounts such as an HSA, Healthcare FSA, and Dependent Care FSA, and life and disability coverage, all within a flexible, remote-first work environment.