Fractional CTO · Cambridge, MA
Senior technical leadership for teams building on payments, platforms and AI.
I'm Ryan Aubrey, an engineer with a background at Stripe in payments infrastructure, distributed systems and API design. I work with founders and engineering teams part-time, as their CTO or alongside one.
Experience
Built at Stripe
At Stripe I've worked on the systems that move money: payments infrastructure, distributed systems and the APIs developers build on. That means designing for correctness first, because in payments a retry or a race condition is someone's money.
Add your title, team, years at Stripe and two or three highlights before launch.
- Payments infrastructureHow charges, refunds and payouts stay correct under load.
- Distributed systemsIdempotency, consistency and failure handling in production.
- API designConsistent, versionable interfaces developers can rely on.
- Agentic commerceHow AI agents will discover, buy and pay on behalf of people.
Services
What a fractional CTO engagement covers
Technical strategy and architecture
Turn the roadmap into a system design that scales, with clear trade-offs your team can execute on.
Payments and billing
Checkout, subscriptions, marketplaces and money movement, designed the way payments companies build them.
APIs and platforms
Developer-facing APIs that are consistent, versionable and pleasant to integrate against.
AI and agentic commerce
Get your product ready for AI agents that discover, buy and pay, without giving up control of risk.
Reliability at scale
Distributed systems practices: idempotency, retries, observability and incident readiness.
Engineering leadership
Part-time senior leadership for founders: hiring bar, process and the decisions in between.
Add engagement formats and pricing (e.g. days per month) before launch.
Testimonials
What clients say
Sample quote: Ryan helped us untangle our billing architecture and ship usage-based pricing in a quarter.
Sample quote: The API review alone paid for the engagement. Our partners integrated in days instead of weeks.
Sample quote: Having a fractional CTO who had seen payments at scale changed how we planned our roadmap.
Book a call
Grab 30 minutes on my calendar
Pick a time, pay a $1.00 booking fee through Stripe, and you'll both get a calendar invite by email. The fee keeps the calendar for people who mean it.
- Pick a time
- Pay $1.00 with Stripe Checkout
- Get the invite by email
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