Oisín Maguire
Software Engineer, Backend, Java and Kotlin on AWS, Dublin
Dublin 2oisin.maguire@example.com087 555 0128Summary
Software Engineer with six years building backend services in Java, Kotlin and Python for payments and healthcare products, currently on the core ledger team of a Dublin payments company. Designed the SEPA instant payments service that now clears every euro transfer on the platform, with no reconciliation break since launch. Cares about on-call health, short design documents and code the next engineer can change without fear.
Experience
Software Engineer II, Dodder Payments
– Present
Dublin 2
- Designed and built the SEPA instant payments service in Kotlin and Spring Boot, handling 2,800 transfers per second at peak with a ten-second end-to-end limit, replacing a batch process that settled once an hour.
- 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 team's incident review process; pages per on-call week fell from nine to two over a year, and the runbooks I wrote are now the template for the platform group.
- Wrote the design and migration plan for moving four services to Kubernetes on AWS in the Dublin region, completed with no customer-facing downtime and with data residency kept inside the EU for GDPR.
Software Engineer, Corrib Health Software
–
Galway
- Built the appointment scheduling API in Java and PostgreSQL used by 140 GP practices and the patient app, with slot searches returning in under 200 ms.
- Replaced a nightly HL7 file import with an event-driven pipeline on Kafka, so lab results reach the practice within minutes rather than the next morning.
- Added contract tests between five services, which caught breaking API changes before each release and cut hotfixes in half over the following year.
Education
BSc (Hons) Computer Science, First Class, NFQ Level 8
University of Connacht, Galway
Final year project on distributed consensus; eight-month placement with a Galway medical device company.
Skills
- Java and Kotlin
- Python
- Spring Boot
- PostgreSQL
- Kafka
- Redis
- Kubernetes
- AWS (EKS, RDS, SQS)
- Terraform
- REST and gRPC
- Observability (Prometheus, Grafana)
- CI/CD with GitLab
Certifications
- AWS Certified Solutions Architect – Associate, Amazon Web Services,