Senior/Staff Software Engineer

Lighten Engineer RoleLighten envisions a future where clinical data can drive the next generation of human health breakthroughs — from uncovering personalized treatment insights, to accelerating drug discoveries and driving adoption of innovative therapies. Lighten builds AI-native software platforms to transform raw clinical data into the highest quality patient journeys to accelerate evidence generation for R&D and bring life-saving therapies to the market faster. We partner with and empower life sciences and healthcare organizations to deliver on their mission for the benefit of the patients they serve.We offer competitive salary and employee equity options, 3% company-sponsored 401k contributions, and comprehensive medical, dental and vision insurance for employees and their families.The RoleWe're looking for an Engineer to help us build and scale the core platform that powers our data products. You'll work across the stack — from data infrastructure and backend services in AWS to the user-facing applications our customers rely on — and you'll play a key role in how we bring agentic AI capabilities into the product.This is a high-ownership role for someone who's comfortable moving between infrastructure, backend, and frontend work, and who wants to help shape both the technical architecture and the engineering culture of a growing team.What You'll DoDesign, build, and ship full stack features across our platform — from data pipelines and APIs to the frontend experiencesOwn and evolve our AWS infrastructure: provisioning, scaling, security, cost efficiency, and reliability for systems handling healthcare dataArchitect and implement agentic AI workflows that improve how users interact with real-world dataPartner closely with product, data science, and commercial teams to translate healthcare domain requirements into robust technical solutionsEstablish and improve engineering practices — code review, testing, CI/CD, observability — as the team scalesMake thoughtful architectural decisions with an eye toward data privacy, PHI handling, and compliance requirements inherent to healthcare dataMentor other engineers and help set technical direction as a senior technical voice on the teamWhat We're Looking ForA strong track record shipping production systems end-to-endDeep experience in at least one of backend/systems design, infrastructure, AI, or frontend, and the ability to go across all of them:Backend / systems design: you design services and data models others build on, and you sweat the things that break under load, concurrency, consistency, failure modes (Python, Node.js, Go, or similar). Think: re-architecting a data pipeline to process 10x the volume, designing an API that a dozen teams depend on, or tracking down the race condition nobody else could.Infrastructure: you design and run AWS in production, not just use it, and you own scaling, security, cost, and reliability as code (ECS/EKS, Lambda, RDS, S3, IAM, VPC). Think: standing up infra-as-code from scratch, cutting cloud spend in half without downtime, or building CI/CD and observability the whole team leans on.AI: you ship LLM and agentic systems that actually hold up, treat quality as something you measure, and make the loop smarter from real usage. Think: building an eval harness that turns "it feels better" into a number, taking an agent from flaky demo to reliable in production, or wiring real usage back into the loop.Frontend: you own features end-to-end and build interfaces that feel effortless and stay solid on messy, real-world data (React/TypeScript or similar). Think: shipping a complex data-heavy view that stays fast, taming gnarly async state, or setting the component patterns everyone else builds on.Excellent judgment on trade-offs: you move fast without cutting the corners that matterStrong communication and the ability to work with non-engineering stakeholders (commercial, clinical, product)A commitment to clean architecture, readable code, and thorough testing, and a multiplier mindset that lifts the team