Principal Full Stack AI Engineer

Validity; Boston (MA); Hybrid; USD 200,000 - 220,000; Full time

Job summary

Validity is building the next generation of email marketing tools with AI at the core. This role focuses on shipping AI-powered features and agentic systems that help customers succeed, combining fast iteration with strong engineering practices.

You will design, implement, and review full-stack features across multiple projects, collaborate with product teams, and push for production-grade quality and scalable architectures.

Qualifications

• 10+ years of engineering experience shipping impactful products.
• Deep full-stack experience with React, Next.js, TypeScript, and PostgreSQL.
• 2+ years building agentic AI systems.
• Ability to work across multiple projects simultaneously using agents to multiply output.
• Strong code review skills to maintain high quality in an AI-assisted development environment.
• Strong product sense and understanding of user needs.
• Excellent systems design for clarity, maintainability, and scale.
• Bias toward action and rapid decision-making.

Responsibilities

• Quickly build and ship full-stack features.
• Design and deploy agentic AI systems that solve real user problems.
• Work across multiple projects simultaneously, using agents to maintain velocity and context across concurrent workstreams.
• Perform rigorous code review – especially of AI-generated code – ensuring production-grade quality, security, and systems design.
• Set technical direction through architecture decisions, prototypes, and rapid experimentation.
• Help define and improve evaluation for agent-powered features.
• Move from idea to production-ready implementation at speed.
• Work closely with product managers, shipping, learning, and iterating.

Tools

React

Next.js

TypeScript

PostgreSQL

Job description

About the Role

We'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.

Team Dynamic

We 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 Responsibilities

• Quickly build and ship full-stack features
• Design and deploy agentic AI systems that solve real user problems
• Work across multiple projects simultaneously, using agents to maintain velocity and context across concurrent workstreams
• Perform rigorous code review – especially of AI-generated code – ensuring production-grade quality, security, and systems design
• Set technical direction through architecture decisions, prototypes, and rapid experimentation
• Help define and improve evaluation for agent-powered features
• Move from idea to production-ready implementation at speed
• Work closely with product managers, shipping, learning, and iterating

Required Experience, Skills, and Education

• 10+ years of engineering experience shipping impactful products
• Deep full-stack experience with React, Next.js, TypeScript, and PostgreSQL
• 2+ years building agentic AI systems
• Demonstrated ability to work across multiple projects simultaneously, leveraging agents to multiply output
• Strong code review skills with the judgment to maintain high quality in an AI-assisted development environment
• Strong product sense – you understand the product and what users want
• Excellent systems design – you architect for clarity, maintainability, and scale
• Bias toward action and rapid decision-making

Who You Are

• A doer – hands-on with code and experiments daily
• A quality gate – you care about getting it right, and you know AI-generated code needs sharp review
• Fast and intelligent – you learn fast, make smart decisions quickly, and iterate
• An AI-native builder – agentic tools are part of how you work, not an afterthought
• Experimentation-obsessed – you validate through building
• Comfortable with ambiguity – you forge ahead when the path isn't clear
• Collaborative – you thrive on code review and learning from others
• Hard-working and motivated – you put in the effort and take pride in what you ship

Preferred Experience, Skills, and Education

• History 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-Hybrid

Equal Employment Opportunity Statement

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Validity is proud to be an equal opportunity employer. We are committed to providing equal employment opportunities to all employees and applicants for employment regardless of actual or perceived race, color, ancestry, national origin, citizenship, religion or creed, age, physical or mental disability, medical condition, AIDs/HIV status, genetic information, military and veteran status, sex, parental status (including pregnancy and pregnancy-related conditions, childbirth, post childbirth, nursing mother, parent of a young child and parent of a foster child), gender (including gender identity and expression), sexual orientation, marital status (including registered domestic partner status), or any other characteristic protected by applicable federal, state, or local law.

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