Ethan Kowalczyk
Software Engineer, Backend and Cloud (Go, TypeScript, AWS), Australian citizen
Fitzroy, VICethan.kowalczyk@example.com0491 572 318Summary
Software Engineer with six years building backend services in Go and TypeScript for payments and agritech products on AWS. Designed the settlement service that now reconciles every merchant payout on the platform, with no reconciliation break since launch, and cut the team's cloud bill by about a third. Cares about on-call health, clear design documents and code the next engineer can change safely.
Experience
Software Engineer, Flinders Lane Payments Pty Ltd
– Present
Melbourne, VIC
- Designed and built a merchant settlement service in Go that reconciles 2,800 payouts an hour at peak against the bank's NPP and BECS files, replacing a batch job that ran overnight.
- Cut p99 latency on the card authorisation path from 390 ms to 160 ms by removing two synchronous calls and adding a read-through cache in Redis.
- Led the incident review process for the team; pages per on-call week fell from nine to two over a year, and the runbooks are now the template for the platform group.
- Right-sized the team's RDS and ECS footprint in the Sydney region and moved batch work to spot capacity, cutting the monthly AWS bill by about a third.
Software Engineer, Goulburn Valley Agritech
–
Shepparton, VIC
- Built the irrigation telemetry API in TypeScript and PostgreSQL used by 900 farm accounts and the grower web app, ingesting sensor readings every five minutes.
- Replaced a nightly CSV import with an event-driven pipeline on SQS and Lambda, so soil moisture alerts reach growers in seconds instead of the next morning.
- Added contract tests between four services, which caught breaking API changes before release and ended a run of weekend hotfixes.
Education
Bachelor of Computer Science
University of the Yarra Valley, Melbourne, VIC
Skills
- Go
- TypeScript and Node.js
- PostgreSQL
- Redis
- AWS (ECS, Lambda, RDS, SQS)
- Terraform
- Docker and Kubernetes
- gRPC and REST
- Observability (Datadog, Grafana)
- CI/CD (GitHub Actions)
- System design
- Payments and reconciliation
Certifications
- AWS Certified Developer – Associate, Amazon Web Services,