Elias Kosunen
Senior Lead Software Engineer at LSEG (London Stock Exchange Group)
Vantaa, Mainland Finland
Summary
🤩
Rockstar🎓
Top SchoolElias Kosunen is a Senior Lead Software Engineer with 11 years of experience, currently driving engineering efforts at LSEG and operating as a freelance developer from Vantaa, Finland. A focused C++ expert and ISO C++ committee member, he contributes to language evolution while shipping robust production code. His open-source work includes significant low-level fixes and CI improvements to widely used projects like fmtlib and scnlib, demonstrating attention to compiler portability, undefined behavior, and Unicode and parsing robustness. He pairs embedded and backend experience from consultancy roles with practical library-level expertise, making him adept at both systems engineering and toolchain-quality improvements. Notably, his contributions often address subtle compiler diagnostics and build reproducibility—changes that quietly elevate long-term code quality across ecosystems.
10 years of coding experience
4 years of employment as a software developer
High School Diploma High School/Secondary Diplomas and Certificates, High School Diploma High School/Secondary Diplomas and Certificates at Järvenpään Lukio
Stackoverflow
433reputation
28kreached
18answers
7questions
Github Skills (18)
c-language10
cross-platform10
compiler-optimization10
cprogramming-language10
text-formatting9
formatting9
unicode9
performance-optimization9
build-system8
unit-testing8
cicd7
html6
fork6
php6
segmentation-fault6
Programming languages (13)
Github contributions (5)
eliaskosunen/scnlib
Nov 2018 - Jul 2022
scanf for modern C++
Role in this project:
Back-end Developer & Library Contributor
Back-end Developer & Library ContributorContributions:23 releases, 551 commits, 40 PRs in 3 years 8 months
Contributions summary:Elias contributed significantly to the development and refinement of scnlib, focusing on low-level library enhancements. Their work encompassed fixing build issues, improving the handling of Unicode characters, and optimizing the parsing of integers and floating-point numbers. The user's efforts also extended to expanding the library's functionality through the introduction of specialized classes and methods for list scanning and format string handling, showcasing a focus on enhancing the core parsing capabilities of the library.
cppclangc-plus-plusconstexprparsing
fmtlib/fmt
Mar 2018 - Feb 2019
A modern formatting library
Role in this project:Back-end Developer
Back-end DeveloperContributions:10 commits, 6 PRs, 60 comments in 10 months
Contributions summary:Elias primarily focused on fixing compiler warnings and errors related to the fmtlib library. Their contributions involved removing deprecated functionalities, addressing undefined behaviors, and resolving issues flagged by various compilers, especially clang and MSVC. The changes mainly concerned the library's internal workings, like fixing warnings related to integer conversions and compiler versions, and generally improved code quality. The user also enhanced the CI/CD setup by adding more compilers and increasing the warning levels.
chronorustc-plus-plusperformanceprintf
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.