Sam Whitfield
Staff Software Engineer
Summary
Backend and platform engineer with eleven years building systems that stay up. Most recently staff engineer on a payments platform handling 40 requests a second at peak, where I cut p99 latency from 1.4s to 180ms. Equally happy writing the migration, the runbook, and the test that proves it.
Experience
Ledgerline
Mar 2020 – Present
Remote
Staff Software Engineer
- Led the migration of the billing service off the monolith to an event-driven design, removing a nightly reconciliation batch that had taken four hours a night since 2016.
- Cut p99 checkout latency from 1.4s to 180ms by fixing two N+1 query paths and adding a read-through cache; the service now handles 40 requests a second at peak.
- Took our on-call rotation from 12 pages a week to 3 by fixing three long-standing failure modes and writing the runbooks we did not have.
- Mentored four engineers; two now lead their own teams.
Corvus Systems
Jul 2017 – Feb 2020
Seattle, WA
Senior Software Engineer
- Built the public API and its rate limiting layer, serving 340 partner integrations with no downtime in 14 months.
- Reduced infrastructure spend by 31% ($420k a year) by right-sizing instances and retiring two services nobody was calling.
- Introduced trunk-based development with a 30-minute deploy; release frequency went from fortnightly to daily.
Bramble Digital
Aug 2013 – Jun 2017
Portland, OR
Software Engineer
- Maintained a Rails application serving 1.2M monthly users across six third-party integrations.
- Wrote the billing-path integration suite the team still runs, covering 94% of the payment code.
Education
University of Washington
2009 – 2013
B.S. Computer Science
Skills
Languages Go, Python, TypeScript, SQL, Ruby
Systems Distributed systems, PostgreSQL, Kafka, Kubernetes, AWS
Practice Code review, on-call design, technical writing, mentoring
Open source
pg-replay
2022 – Present
Load-testing harness for Postgres, 900 GitHub stars
- Replays anonymised production query traces; three companies have used it to size database hardware before buying it.
Certification
AWS Certified Solutions Architect – Associate
2021
Amazon Web Services