AI-First Frontend Experience Engineer

Polygon.io, Inc; Northern (KY); Hybrid; USD 140,000 - 210,000; Full time

Benefits offered by this job

Comprehensive medical plans

401(k)

Unlimited time off

Job summary

Massive is seeking a Principal Product Experience Engineer to help define how product development works in an AI-first world. This cross-functional role combines frontend engineering, product judgment, and UX sensibility, with AI as a core part of thinking, building, and iterating.

You will work across problem framing, experience design, and implementation to create new user experiences end to end, owning initiatives from hypothesis to shipped experiences, and collaborating with product, design,

Qualifications

• Proven ability to design and implement complex, high-quality interfaces with excellent interaction and polish.
• Strong architectural instincts for frontend systems that scale in complexity without becoming brittle.
• Comfort owning the frontend end to end, from initial prototype to long-lived production code.
• Strong product judgment with the ability to frame work as hypotheses and evaluate outcomes using real signals.
• Strong instincts around scope, sequencing, and tradeoffs.
• Practical UX sensibility—you can execute thoughtful UX without relying entirely on mocks.
• AI-native workflow with meaningful use of AI tools in day-to-day work.

Responsibilities

• Own product initiatives from hypothesis to shipped experience, with clear intent and validation signals.
• Use AI extensively to accelerate prototyping, implementation, iteration, and exploration of UX ideas.
• Design and build complete user experiences, from interaction models to polished, production-ready frontend code.
• Start with small bets and ship early versions to learn and refine.
• Iterate based on real-world usage and feedback, deciding when to continue, adjust, or stop.
• Partner with product, design, and QA to clarify problems, define quality bars, and maintain coherence without heavy handoffs.

Skills

Frontend engineering

UX design sensibility

Product judgment

AI-native workflow

Ownership

Cross-functional collaboration

Prototype to production

Analytics mindset

Problem framing

Execution under uncertainty

Tools

PostHog

Amplitude

AI tools

Job description

Massive is seeking a Principal Product Experience Engineer to help define how product development works in an AI-first world. This cross-functional role combines frontend engineering, product judgment, and UX sensibility, with AI as a core part of thinking, building, and iterating.

You will work across problem framing, experience design, and implementation to create new user experiences end to end, owning initiatives from hypothesis to shipped experiences, and collaborating with product, design,