Sebastian Alfers
Software Engineer, Developer Support at Akka
Germany
Summary
🤩
Rockstar🎓
Top SchoolSebastian Alfers is a seasoned software engineer with 15 years’ experience building resilient backend systems and supporting developer ecosystems, currently focused on Developer Support at Lightbend/Akka. He has a strong Scala/Java background and practical expertise in distributed systems and persistence—evidenced by contributions to high-profile open-source projects like Akka and akka-grpc where he improved snapshot persistence, synchronization, and gRPC error handling. His career spans product-scale engineering roles at SoundCloud, FlixBus and Zalando, and academic work on cluster-based dimensionality reduction, blending applied research with production engineering. Based in Germany, he combines hands-on backend development with a knack for clear developer-facing documentation and tooling that bridges Java and Scala APIs.
14 years of coding experience
6 years of employment as a software developer
Bachelor of Science (B.Sc.), Computer Software Engineering, Bachelor of Science (B.Sc.), Computer Software Engineering at Technische Fachhochschule BerlinMa, Ma at Hochschule für Technik und Wirtschaft Berlin
Github Skills (16)
testing10
javas10
error-handling10
persistence10
exception-handling10
akka10
java10
concurrency10
grpc10
scala10
actor9
actor-model9
akka-http9
remote-actors9
distributed-systems9
Programming languages (15)
Github contributions (5)
akka/akka-grpc
Jan 2021 - Aug 2022
A platform to build and run apps that are elastic, agile, and resilient. SDK, libraries, and hosted environments.
Role in this project:
Back-end Developer
Back-end DeveloperContributions:2 releases, 24 reviews, 7 commits in 1 year 7 months
Contributions summary:Sebastian primarily contributed to the Akka gRPC project by implementing and refining the error handling and exception mapping within the gRPC framework. They modified code to handle `StatusRuntimeException` in exception handlers, ensuring proper error propagation. Additionally, the user documented the manual approach for using the rich error model, which involved integrating custom error details. Furthermore, the user was involved in adapting code to align the Java and Scala API for more streamlined operations.
rpcakka-grpcprotobufgrpcstreaming
akka/akka
Jul 2020 - Jan 2023
A platform to build and run apps that are elastic, agile, and resilient. SDK, libraries, and hosted environments.
Role in this project:Backend Developer
Backend DeveloperContributions:7 releases, 53 reviews, 12 commits in 2 years 6 months
Contributions summary:Sebastian's commits primarily focus on enhancements to the Akka Persistence Testkit, a component of the Akka framework. They modified internal storage implementations, specifically `InMemStorage` and `SnapshotTestKit`, to improve synchronization and index management. The changes introduce the use of a `Queue` and immutable collections to ensure data consistency. Furthermore, they implemented tests related to snapshot events and retention criteria, reflecting a focus on persistence-related functionality within the Akka ecosystem.
resilientactor-modelreactiveconcurrentdistributed-actors
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