Senior Full Stack Engineer

I'm recruiting on behalf of a YC-backed healthcare data startup, building a unified knowledge graph of 9 million+ US healthcare professionals. Powered by AI agents, their platform lets pharma Medical Affairs and MSL teams identify, understand and engage the medical experts who matter most to them. They're a fast-moving team of 6 delivering mission-critical solutions to major pharma clients under real, tight deadlines. Their core engineering challenge is genuinely hard: complex data entity resolution, connecting disparate registries, publications and organisation records that often share no common identifiers, and turning that mess into reliable, real-time analytics and actionable signals. They're hiring a Senior Fullstack Engineer. They want a technical leader who leads by building: writing production code, designing systems, making architectural decisions, debugging hard problems, and raising the bar for the team, while also playing a senior role in technical conversations with enterprise pharma clients. What you'll own: Build and ship, writing high-quality production code and personally owning important parts of the platform. Technical direction across data, backend and full-stack systems. Engineering leadership, mentoring engineers and setting technical standards without needing a large management structure to do it. Production ownership, investigating incidents and making sound calls when things break. Data at scale, designing systems that handle large, messy, heterogeneous real-world datasets and difficult entity-matching problems. Customer-facing engineering, working directly with enterprise clients on requirements, integrations, security and delivery. What they're looking for: a genuine builder who has personally shipped and owned production systems, not just a workstream inside a larger organisation. Someone who's led engineers while staying hands-on, comfortable with ambiguity, messy data and direct customer exposure. Early-stage startup experience is strongly preferred; healthcare or life sciences experience is a bonus, not a requirement. Interested, or know someone who fits? Apply directly or send me a message: Max.Benmayor@Arrowsgroup.com