Principal Full Stack AI Engineer

AppBuddy; Boston (MA); On-site; USD 200,000 - 220,000; Full time

Job summary

Validity is hiring a Principal Full Stack AI Engineer in Boston to ship AI-powered features and design robust systems. You will lead full-stack development across React, Next.js, and TypeScript, building agentic AI capabilities at scale.

You are a hands-on doer with a passion for quality, and you will mentor others while guiding architectural decisions. This role emphasizes rapid iteration, production-grade security, and collaboration across product teams.

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 leveraging agents to multiply output.
• Strong code review skills with judgment to maintain high quality in AI-assisted development.

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.

Skills

React

Next.js

TypeScript

PostgreSQL

Agentic AI

Code review

Product sense

Systems design

Cross-project collaboration

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.

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 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.

About Validity

For over 20 years, tens of thousands of organizations across the world have relied on Validity solutions to target, contact, engage, and retain customers – using trustworthy data as a key advantage. Validity’s flagship products – Everest, DemandTools, BriteVerify, and GridBuddy Connect – are all highly rated, #1 solutions for sales and marketing professionals. These solutions deliver smarter email campaigns, more qualified leads, more productive sales, and ultimately faster growth.

Validity is a truly unique company - massive revenue growth, top-tier investors, 5-star product ratings, proven ability to acquire and integrate top tech companies and welcome them into the Validity family, a winning culture, and a work environment that fosters hard work, trust, and fun.

Headquartered in Boston, Validity has offices in Denver, London, Sao Paulo, and Sydney. For more information, connect with us on LinkedIn, Instagram, and Twitter.

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.