# Senior Software Engineer - Infrastructure at Sixtyfour

- Company: Sixtyfour (YC P25)
- What the company does: Intelligence Infrastructure on People and Entities. Backed by Y Combinator.
- Company website: https://www.sixtyfour.ai/
- Type: Startups (AI role)
- Level: Senior
- Location: San Francisco, CA, US
- Work setup: On-site
- Pay: $150K to $225K base salary per year (USD)
- Posted: 2026-07-22
- Apply by: 2026-10-08
- Apply: https://www.ycombinator.com/companies/sixtyfour/jobs/mVKkiel-senior-software-engineer-infrastructure
- Page: https://www.1752.vc/careers/jobs/sixtyfour-senior-software-engineer-infrastructure/

## 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)

Tags: Engineering