Staff Software Engineer, Backend (Observability)

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most. The Observability team builds the platform every Affirm engineer relies on to understand the behavior and performance of our systems. Our platform ingests 200+ TB/day of metrics, logs, and traces from hundreds of services across 80+ Kubernetes clusters, and when a user's checkout fails, our data is how engineers find out why.

Over the next year, we’re moving to wide events, with one context-rich event per request, improving the signal-to-noise ratio to make debugging faster. We’re also introducing log sampling and building observability best practices into agentic development and code review, so that AI-assisted code is well instrumented by default. We’re looking for a Staff Software Engineer to be the technical lead for Observability.

You’ll spend most of your time hands-on while defining the roadmap, driving cross-functional projects, mentoring a team of six engineers, and partnering closely with infrastructure and product teams. What You'll Do · You will own the architecture of Affirm’s telemetry pipeline, balancing reliability, query performance, and cost at 200+ TB/day. · You will design log sampling strategies that significantly reduce volume and cost without losing the signal engineers need during incidents.

· You will shape how observability fits into agentic development, so that AI coding ag