About
From architecture through production support.
Gnar.li is led by Billy Heaton, a full-stack software engineer and technical lead. When you work with Gnar.li, you work with Billy directly.
Background
Products, APIs, and the teams that build them
Billy has built software professionally since 2008, across APIs, financial software, customer-facing applications, security, and engineering management. He owns delivery from architecture through production support.
At Gnar.li he builds and runs Gnarly Budget, a privacy-first budgeting app that plans around payday and imports bank files instead of connecting to banks.
Résumé
Before Gnar.li
These were in-house roles held as an employee of each company. They are not Gnar.li projects or client engagements.
Sumit Software · Senior Product Engineer
2025–2026
- Engineered full-stack solutions leveraging AI agentic workflows to contribute on new features for partnership accounting and investment transactions.
- Enhanced family office accounting software with fault tolerance for synchronization errors in payments.
- Fortified customer general ledger data integrity by implementing locks on bank and investment-sourced journal entries.
Kajabi · Senior Software Engineer II
2022–2025
- Led the Public API from architecture through implementation, testing, documentation, launch, and support, delivered as a Pro Plan offering.
- Published OpenAPI specifications, Postman collections, and developer documentation; coordinated critical data migrations.
- Established Datadog dashboards, SLOs, health metrics, and alerting. Founded the API Guild and mentored engineers.
- Delivered social login, multi-factor authentication, entitlements, and plan-limit enforcement.
Functional Inc. · Senior Software Engineer
2021–2022
- Led front-end and back-end delivery of a payroll system for an at-home care company; mentored engineers and advised the board on acquisition technology reviews.
Envoy · Engineering Manager, previously Senior Software Engineer
2018–2021
- Managed the growth, deliveries, and dashboard teams, and led dashboard modernization across the design system, legacy code, and developer experience.
- Built customer, administrator, and employee dashboards; led the deliveries project and contributed to GraphQL services for mobile clients.
Q2ebanking · Senior Software Developer
2017–2018
- Built an account-opening form builder supporting anti-money-laundering and fraud requirements, migrated JavaScript to TypeScript, and released an open-source runtime error-tracking library.
TBWA/Media Arts Lab · Software Development Manager
2015–2016
- Managed a team building internal applications for the agency’s work with Apple; improved agile delivery and supported open-source contributions.
CrowdStrike · Senior UI Engineer
2014–2015
- Contributed to the UI layer of the Falcon Host product for cybersecurity – malware detection, adversary activity, and damage prevention from targeted attacks.
- Facilitated the replacement of existing functionality with modular applications, incrementally updating functionality as the app was averse to change.
Technical specialties
Where I’m most useful
- Full-stack product engineering
- Public APIs and OpenAPI
- Financial software and data integrity
- Self-hosted AI: retrieval, evaluation, validation
- Web application security and identity
- Test-driven development and Playwright automation
- Observability and production support
- Engineering leadership and mentoring
Development philosophy
Understand the real problem. Make the smallest useful change. Create fast feedback. Leave the team stronger.
Start with the real problem
Understand the users, business context, constraints, and desired outcome.
Work in small increments
Frequent demos, pull requests, pairing, and releases keep everyone’s understanding shared.
Prefer simple solutions
Designs that are understandable, maintainable, and appropriate to the problem.
Test from the outside in
Tests clarify important behavior and protect the workflows that matter most.
Communicate clearly
Decisions, risks, tradeoffs, and progress stay visible.
Leave the team stronger
Document the work, share knowledge, and mentor teammates so the system stays maintainable.
AI-assisted development
Using AI responsibly
AI tools increase leverage. They don’t replace judgment. I use them while keeping human review, testing, security, and accountability where they belong — and I help teams do the same.
Location and availability
Clackamas County, Portland, and Vancouver
Based in Gladstone, Oregon, and available to meet in person across the area. Remote work is available with teams anywhere in the country.
- Clackamas County, Oregon
- Portland, OR metro area
- Vancouver, WA metro area