Principal Full Stack AI Engineer

About the RoleWe're building the next generation of email marketing tools at Validity. AI is central to how we build – we develop with agents daily – and to what we build, shipping AI-powered features that help our customers succeed.We're looking for a Principal Full Stack AI Engineer who ships fast, designs systems that last, and holds a high-quality bar across a team that builds with AI every day.Team DynamicWe move fast, communicate directly, and debate ideas openly. The best idea wins regardless of who it comes from. We bias toward action – ship, learn, iterate.Position Duties and ResponsibilitiesQuickly build and ship full-stack featuresDesign and deploy agentic AI systems that solve real user problemsWork across multiple projects simultaneously, using agents to maintain velocity and context across concurrent workstreamsPerform rigorous code review – especially of AI-generated code – ensuring production-grade quality, security, and systems designSet technical direction through architecture decisions, prototypes, and rapid experimentationHelp define and improve evaluation for agent-powered featuresMove from idea to production-ready implementation at speedWork closely with product managers, shipping, learning, and iterating Required Experience, Skills, and Education10+ years of engineering experience shipping impactful productsDeep full-stack experience with React, Next.js, TypeScript, and PostgreSQL2+ years building agentic AI systemsDemonstrated ability to work across multiple projects simultaneously, leveraging agents to multiply outputStrong code review skills with the judgment to maintain high quality in an AI-assisted development environmentStrong product sense – you understand the product and what users wantExcellent systems design – you architect for clarity, maintainability, and scaleBias toward action and rapid decision-makingWho You AreA doer – hands-on with code and experiments dailyA quality gate – you care about getting it right, and you know AI-generated code needs sharp reviewFast and intelligent – you learn fast, make smart decisions quickly, and iterateAn AI-native builder – agentic tools are part of how you work, not an afterthoughtExperimentation-obsessed – you validate through buildingComfortable with ambiguity – you forge ahead when the path isn't clearCollaborative – you thrive on code review and learning from othersHard-working and motivated – you put in the effort and take pride in what you ship Preferred Experience, Skills, and EducationHistory of 0-to-1 projects Base salary range $200,000 - $220,000, plus benefits, bonus opportunities and stock options. Final salary may vary depending on skills, location, and/or experience. #LI-HybridSummaryLocation: Boston, MA, United StatesType: Full TimeExperience: ExperiencedDepartment: Engineering