Staff Full Stack Engineer - Pay-i
Confirmed on the employer's own hiring board on Oct 17, 2026. First seen by Alion on Oct 29, 2025. Pear VC scores A on the Alion truth index.
Staff Full Stack Engineer
About Pay-i
At Pay-i, we are solving one of enterprise AI's most critical challenges: proving ROI of GenAI investments. While global GenAI spend races toward $600B by 2028, 72% of CIOs cite measurement and forecasting as their top blocker, and only 13% of business leaders report significant enterprise-level value from GenAI. We are the only platform that transforms every model call, prompt, and agent step into CFO-grade metrics, providing enterprises the financial transparency to identify winning use cases, optimize costs, and prove impact.
Founded by ex-Microsoft leaders with 20+ years of experience each, Pay-i is a seed-stage company backed by five venture capital firms and executive/C-suite angels from Microsoft, Twilio, Zoom, and more. If you are passionate about selling products that fundamentally change how enterprises scale their AI initiatives, join us in bringing the system of record for GenAI ROI to market.
The Opportunity
As our Staff Full Stack Engineer, you will be a crucial team member working closely with other Full Stack Engineers responsible for implementing our customer’s front-end experience. This is a unique opportunity to build with a deeply experienced team and GenAI leaders who like to innovate, experiment, and respond to customer feedback.
What You'll Do
Are you excited about building an innovative product that tackles some of the most pressing financial challenges associated with leveraging Generative AI? As our Staff Full Sack Engineer, you will play a pivotal role in our mission. Your efforts will not only shape the user experience across our dashboards, websites, and products but also lay the foundation for our future growth.
Core Responsibilities:
Work with Pay-i's front-end and back-end engineers to rapidly deliver both prototype and production-quality products
Create high-quality and enjoyable user experiences by building interfaces that are simple, intuitive, performant, and reliable
Ensure high-quality graphic standards and brand consistency across all customer touchpoints
Implement responsive design principles to ensure seamless display across various devices and screen sizes
Refactor existing code to improve performance, structure, and readability
Utilize state management libraries and patterns (e.g., Redux, Context API) to manage application state efficiently
Implement front-end security best practices, such as input validation and secure coding standards
Implement unit tests, integration tests, and end-to-end tests using appropriate testing frameworks and tools
Perform code reviews and participate in peer code reviews to maintain code quality
Inform our process for ensuring maintainability, quality, and performance of our entire front-end stack
What You Bring
Required Qualifications:
7+ years of experience, and insatiable curiosity that has only grown during that time
Deep expertise in modern client Javascript, HTML 5, CSS, and Browser Dev Tools
Practical protocol knowledge of DNS, HTTP, and OAuth2
Experience with git, bash, Docker, and Python web server development
Excel at working in a fast-paced "bring up/tear down" environment
Comfortable working in ambiguous environments and defining the path forward
Proven experience building external customer-facing products
Self-directed and self-aware, you have strong opinions and a stronger work ethic
Cloud experience (AWS, Azure, and GCP)
Preferred Qualifications:
10+ years of experience
Highcharts, Bootstrap 5+
Experience building a SPA and/or PWA in Javascript
Full-stack engineering capabilities
What We Offer
Top-of-the-line health insurance
Discretionary time off
Opportunity to grow with the company and manage a team
Fast-paced, execution-focused environment with clear goals
Collaboration with and mentoring from an extremely experienced founding team
Location
Based in Bellevue, WA
Local, in-office presence preferred
Occasional hybrid arrangements possible
Why Pay-i?
You'll join an extremely experienced team with a unique, patented value proposition and clear goals. We're well-funded, well-connected, and set up for success-now we need the right people to execute on our vision. As one of our early technical hires, you'll have complete ownership over the front-end architecture and the opportunity to shape our engineering culture as we grow.
Pay-i is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees.