Intelligence Infrastructure on People and Entities. Backed by Y Combinator.
About the role
We're looking for a Senior Software Engineer to join our core Engineering team and help build the infrastructure Sixtyfour runs on. This is a hands-on, high-ownership role spanning backend systems, API design, billing, and infra scaling. This is the kind of work that shapes not just what we ship, but how we build for years to come.
What they're looking for
- 3–7 years of professional software engineering experience
- Experience as a team lead or tech lead — comfortable providing technical direction and mentorship without needing direct reports to do so
- Strong API design and backend development experience
- Experience with observability
- Experience with backend infrastructure and scaling systems in production
- Experience building or maintaining billing/payments systems (Stripe or similar)
More about this role
Sixtyfour helps teams understand the people, companies, and entities they interact with. With a primary focus on Compliance (AML/KYB), Trust & Safety, Cybersecurity, and Investigations. Our platform combines agents, LLMs, and large-scale data infrastructure to surface data other platforms can't.
We're looking for a Senior Software Engineer to join our core Engineering team and help build the infrastructure Sixtyfour runs on. This is a hands-on, high-ownership role spanning backend systems, API design, billing, and infra scaling. This is the kind of work that shapes not just what we ship, but how we build for years to come. You won't have direct reports, but you'll operate as a technical leader from day one: setting the standards, shaping architecture decisions, and mentoring engineers as the team grows around you.
If you're the kind of engineer who gets excited about API design, scaling infrastructure, and payments/billing systems, let’s talk.
- Own and evolve core backend infrastructure as we scale usage and traffic
- Design and build robust, well-architected APIs that power our core product and developer platform
- Build and maintain billing and payments infrastructure...
Browse similar: AI jobs · AI startup jobs · Startup jobs · San Francisco Bay Area