Fredrik Wärnsberg
VP Of Technology at Soundtrack Your Brand
Stockholm, Stockholm County, Sweden
Summary
🤩
Rockstar🎓
Top SchoolFredrik Wärnsberg is a veteran technology leader with 13 years of experience, currently serving as VP of Technology in Stockholm and known for building autonomous teams and resilient distributed systems. He combines hands-on backend craftsmanship in Elixir, Go and Scala with a strong frontend sensibility (React), shipping high-availability APIs and delightful UIs. A prolific open-source contributor, Fredrik has driven important integrations and features in projects like tapir, zio-http and Caliban—bringing pragmatic ZIO/HTTP adapters, routing enhancements and remote GraphQL schema support. He thrives on API design, functional programming and operational reliability, and is as comfortable debugging in the terminal as designing system-wide abstractions. Colleagues value him for turning complex distributed problems into maintainable developer experiences while keeping delivery velocity high.
13 years of coding experience
14 years of employment as a software developer
IT-Gymnasiet UppsalaMSc, Computer Science, MSc, Computer Science at Uppsala University
Swedish, English
Github Skills (23)
json10
elixir10
testing10
http10
zio10
wpgraphql10
akka-http10
scala10
http-client10
http-server10
wordpress-graphql10
graphql10
functional-programming10
api-design9
base64-encoding9
Programming languages (20)
Github contributions (5)
ghostdogpr/caliban
Apr 2021 - Nov 2022
Functional GraphQL library for Scala
Role in this project:
Back-end Developer
Back-end DeveloperContributions:151 reviews, 38 commits, 39 PRs in 1 year 6 months
Contributions summary:Fredrik significantly contributed to the `caliban` project, a functional GraphQL library for Scala. They implemented a `RemoteSchema` feature, enabling the parsing and integration of remote GraphQL schemas. This involved developing new tools, defining data structures, and integrating introspection capabilities. The user also added a ZIO-HTTP adapter, facilitating the usage of Caliban with the ZIO-HTTP library for GraphQL server applications.
graphql-clientfunctional-programminggraphql-librarygraphql-serverscala
zio/zio-http
May 2021 - Nov 2022
A next-generation Scala framework for building scalable, correct, and efficient HTTP clients and servers
Role in this project:Back-end Developer
Back-end DeveloperContributions:26 reviews, 6 commits, 12 PRs in 1 year 6 months
Contributions summary:Fredrik contributed to the zio-http project by implementing new features, specifically adding routing capabilities and enhancing the syntax of HttpApp through the use of implicit classes. These changes include the addition of a `route` method to delegate to other Https and the use of implicit classes for HttpApp syntax to improve usability. The user also implemented combinators like `tap*` which add functionality for side effects during app execution and also added metrics middleware. Furthermore, the user fixed issues like content encoding in `hasContentType`.
zioscala-libraryhttp-clientwebsocketscala
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