Valthor Halldorsson
Member Of Technical Staff at Lovable
Greater Malmö Metropolitan Area Sweden
Summary
👤
Senior🎓
Top SchoolValthor Halldorsson is a Member of Technical Staff with 11 years of experience building production-grade software and ML systems, currently helping a small, multidisciplinary team at Lovable enable plain-English software creation. He brings deep practical expertise in compiler and backend engineering—evidenced by contributions to the Scala 3 compiler (Dotty) where he refactored Java serialization, added tests, and improved UX—and a strong track record in applied NLP from co-founding Donna, where he implemented a high-performance Rust NLP engine and bespoke alignment and Word-rendering solutions. His background spans full-stack teaching and course development at Lund University, hands-on ML engineering at Explosion, and early work on data extraction and static analysis, reflecting a rare mix of systems, language, and product sensibilities. Icelandic-born and now based in Greater Malmö, he blends physics-inspired curiosity with pragmatic shipping velocity and an appetite for language, AI, and clean internal architecture.
11 years of coding experience
6 years of employment as a software developer
Master's degree, Computer Science, Master's degree, Computer Science at The Faculty of Engineering at Lund University
English, Swedish, Icelandic
Github Skills (16)
file-handling10
file-processing10
scala10
javas10
compiler10
data-serialization10
compiler-compiler10
file-access10
fileio10
java10
serialization10
testing9
dotty9
user-interface8
graphical-user-interface8
Programming languages (8)
Github contributions (5)
lunduniversity/introprog
Apr 2016 - Dec 2016
Teaching material for "Introduction to Programming using Scala" at Lund University, LTH. http://cs.lth.se/pgk/
Role in this project:
Full-stack Developer
Full-stack DeveloperContributions:20 commits, 11 PRs, 3 comments in 8 months
Contributions summary:Valthor primarily contributed to the `chords.scala` file, adding commands for a text-based user interface. They implemented functionality for loading chords from files, demonstrating file I/O. The user also made changes to the `Plan.scala` file, indicating involvement in course planning. Furthermore, the commits show updates to the `Turtle` graphics library, fixing formatting and ensuring maze pathing uses the resource directory.
lthteachingscalalund-universityprogramming-courses
scala/scala3
Mar 2017 - Jun 2017
The Scala 3 compiler, also known as Dotty.
Role in this project:Back-end Developer
Back-end DeveloperContributions:5 commits, 3 PRs, 5 comments in 3 months
Contributions summary:Valthor primarily focused on refactoring and enhancing the Java serialization code within the Scala 3 compiler project. They consolidated serialization logic, added unit tests to validate serialization results, and removed unused parameters. Furthermore, the user fixed code style issues and addressed a missing title issue on the search page, indicating a focus on improving the project's internal structure and user interface. These changes suggest a strong understanding of the project's underlying code and a commitment to code quality.
compilerscala3scaladottyepfl
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