Principal Product Experience Engineer

Polygon.io; United States; Remote; USD 100,000 - 130,000; Full time

Job summary

A fintech innovation company in the United States seeks a knowledgeable Product Engineer. This role involves defining product development in an AI-first environment. You will be responsible for creating user experiences end to end, collaborating with cross-functional teams while using AI to enhance your workflow. Ideal candidates should possess advanced frontend engineering skills, a strong product sense, and the ability to develop high-quality applications rapidly. Join a team dedicated to revolutionizing financial market data access.

Qualifications

• Deep mastery of frontend frameworks and APIs.
• Ability to design high-quality interfaces.
• Comfort with AI tools in daily work.

Responsibilities

• Own product initiatives from hypothesis to experience.
• Use AI to accelerate UX prototyping and iteration.
• Design and build user experiences end to end.

Skills

Exceptional frontend engineering skills

Mastery of modern frontend development (React, TypeScript, CSS)

Strong product judgment

AI-native workflow

Experience using product analytics tools

Tools

PostHog

Amplitude

Job description

We are looking for a Product Engineer to help define how product development works in an AI-first world. This is a cross-functional role for someone who combines exceptional frontend engineering skill, strong product judgment, and a solid UX sensibility, and who uses AI as a core part of how they think, build, and iterate.

You will work across problem framing, experience design, and implementation to create new user experiences end to end. Rather than moving work through traditional product, design, and engineering phases, you will operate with a high degree of ownership while collaborating closely with product, design, and QA to shape intent, quality, and direction. This role is about turning ideas into real, testable experiences quickly and learning from what happens next.

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, explicit bets and ship early versions to learn and refine rather than over-planning upfront.
• 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 or queues.

Skills & Qualifications

• Exceptional frontend engineering skills with deep mastery of modern frontend development including React, TypeScript, modern CSS, browser APIs, performance, and accessibility.
• 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 where you already use AI tools meaningfully in your day-to-day work and treat AI as leverage for thinking and building.
• Ownership and follow-through—comfortable carrying work across definition, build, release, and evaluation.
• Experience using product analytics tools such as PostHog, Amplitude, or similar to define signals, evaluate bets, and guide iteration.
• Founder mentality with comfort making decisions under uncertainty and taking responsibility for outcomes.
• Experience working in fast-moving environments where direction is shaped through execution rather than detailed plans.
• Background in financial markets, market data, or data-intensive products is a plus.

About Massive

At Massive we are on a mission to help developers build the future of fintech. We are committed to democratizing access to the world\'s financial market data and enabling developers to build the future of fintech. Join us and be part of a team that is revolutionizing the way we interact with money and value.

If you are a passionate problem-solver who thrives in a dynamic and innovative environment, we encourage you to apply!