Tim Ellison
IBM Distinguished Engineer at South Central Ambulance Service NHS Foundation Trust
Greater Southampton Area United Kingdom
Summary
🤩
Rockstar🎓
Top SchoolTim Ellison is a Distinguished Engineer and Java runtime expert with over 20 years’ experience architecting and shipping enterprise-grade JVMs and open source runtime technologies for companies like IBM and Red Hat. He founded and led pivotal community projects—AdoptOpenJDK and Apache Harmony—and helped build Eclipse Adoptium’s Temurin builds used in global production environments, demonstrating rare depth in both specification-level work and hands-on runtime engineering. Tim advises Fortune 100 executives on large-scale Java infrastructure, specializes in JVM internals, compiler tech, and secure build/test/release automation, and has contributed JVM-focused fixes to high-profile projects such as Apache Spark. Beyond engineering, he’s a community-builder and governance leader (Apache PPMC, Trust governor), blending technical leadership with operational experience in emergency services. His background spans research in medical biophysics to distributed development tools, reflecting a long-standing aptitude for complex systems and cross-disciplinary problem solving.
20 years of coding experience
8 years of employment as a software developer
Postgrad research, Medical Biophysics, Postgrad research, Medical Biophysics at The University of ManchesterBSc, Computer Science, BSc, Computer Science at University of Hull
Github Skills (9)
scala10
javas10
apache-spark10
jvm10
java10
testing10
big-data9
sql8
jdbc7
Programming languages (19)
Github contributions (5)
apache/spark
May 2015 - May 2015
Apache Spark - A unified analytics engine for large-scale data processing
Role in this project:
Back-end Developer
Back-end DeveloperContributions:1 commit, 10 PRs, 21 comments in 1 day
Contributions summary:Tim primarily contributed to improving the Apache Spark codebase, focusing on JVM and Java-related optimizations and bug fixes. The contributions include addressing issues related to early garbage collection in test suites, enhancing size estimation for IBM Java environments, and resolving SSL configuration problems. The user also demonstrated expertise in adapting Spark for compatibility across different JVM implementations and vendors, particularly IBM.
analyticspythondata-processingsqlapache
adoptium/adoptium
Jun 2021 - Jan 2023
Contributions:2 reviews, 63 commits, 11 PRs in 1 year 7 months
javaadoptiumtemurineclipseaqavit
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