Software Engineer cover letter example

Dear Ms. Nakamura,

Your Staff Engineer posting at Wasatch Freight Labs describes a dispatch system that has outgrown its original design and a team that needs someone to set its technical direction. I have done that work twice, and I would enjoy doing it for logistics again, where I started my career.

At Granite Peak Software I designed the scheduling engine that now assigns more than 3 million field service jobs a day for 2,500 customers, in Kotlin on AWS. When our API started slowing under that load, I led a redesign of the query layer and caching, and p99 latency dropped 70%, from 1.2 seconds to 360 milliseconds. Just as important, I wrote the design documents that let six teams agree on how to build around it, 14 of them in all.

I spend much of my time on people and practice. I have mentored seven engineers, four of whom were promoted to senior, and I run our incident review program, which cut repeat incidents from 11 in 2022 to 2 last year. Those reviews focus on fixing systems, not blaming people.

Before that I built the payout service at Beehive Payments, moving $400 million a month with no reconciliation losses, and moved batch settlement onto Kafka so it took two hours instead of 24. My first job was route optimization at Jordanelle Systems for 300 trucking fleets, so dispatch problems are familiar ground.

I bring 11 years of backend engineering in Java and Kotlin on AWS. I would welcome the chance to discuss your architecture and roadmap.

Best regards,

Ryan Castillo