Daniel O'callaghan
Staff Engineer, Data Platform Team
Bavaria, Germany
Summary
👤
Senior🎓
Top SchoolDaniel O'callaghan is a Staff Engineer specializing in data platform architecture with 14 years of hands-on experience building scalable, developer-focused systems across startups and enterprise environments. At Personio he owns the Data Registry and multi-language code generation pipelines, enabling type-safe protobuf-driven contracts consumed by 60+ services and shaping runtime metadata via an Entity Data Model. He combines deep backend expertise (Protobuf/gRPC, Kafka, Go, Kotlin, Gradle) with a history of improving platform reliability and developer productivity through reusable tooling and CI/CD automation. Previously he led cross-team architectural efforts at Airtasker, driving payments migrations, global performance improvements and operational scalability. Comfortable as an individual contributor, tech lead and advisor, he has a knack for turning complex integration and streaming challenges into simple, maintainable solutions. Based in Bavaria, he brings a rare blend of protocol-first engineering and practical developer experience tooling that quietly reduces friction across large microservice estates.
14 years of coding experience
13 years of employment as a software developer
Music Theory and Sound Engineering, Music Theory and Sound Engineering at Coláiste Stiofáin Naofa, Cork, IrelandBachelor's degree Computer Science, Bachelor's degree Computer Science at Munster Technological University
English, German
Stackoverflow
3reputation
1kreached
0answers
3questions
Github Skills (36)
spring-boot-starter9
spring8
grpc-java8
spring-boot8
java8
php-fpm7
raml7
heroku-cli7
spring-cloud6
grpc6
pointer6
posix6
bin-packing6
prometheus-exporter6
hotel-booking5
Programming languages (6)
Github contributions (5)
danielocallaghan/dotfiles
Jan 2012 - May 2022
Contributions:38 commits, 42 pushes in 10 years 5 months
danielocallaghan/danielocallaghan.github.io
Feb 2015 - Apr 2020
Contributions:16 pushes, 2 branches in 5 years 3 months
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