Witold Krecicki
Principal Software Development Engineer at Lorenz Labs
Warsaw, Masovian Voivodeship, Poland
Summary
👤
Senior🎓
Top SchoolWitold Krecicki is a Principal Software Development Engineer based in Warsaw with 11 years building and refactoring large-scale, production-critical systems for companies like Google and Microsoft. He specializes in backend and systems-level engineering, with notable open-source contributions to projects such as Juju (orchestration networking) and BIND9 (DNS server internals), demonstrating deep expertise in networking, provisioning and low-level performance and memory concerns. Witold blends architectural thinking with hands-on refactoring to improve maintainability and integration across complex codebases, and he’s comfortable shaping APIs that drive container and network configuration at scale. Beyond corporate roles he consults on radio protocols and serves on the board of the Internet Society Poland Chapter, reflecting a broader engagement with internet infrastructure and standards. An engineer who prefers durable, elegant improvements over quick fixes, he often surfaces subtle architectural gains that pay dividends in large distributed systems.
10 years of coding experience
22 years of employment as a software developer
University of Warsaw
Github Skills (17)
network-configuration10
apidoc10
multithreading10
c1110
networking10
c1710
go10
api10
dns10
golang10
orchestration10
orchestra10
containerization9
devops9
system-administration8
Programming languages (10)
Github contributions (5)
isc-projects/bind9
Apr 2018 - Oct 2020
Mirror of https://gitlab.isc.org/isc-projects/bind9, please submit issues and PR/MRs in the GitLab. Any issues and PRs opened here will be closed without a comment.
Role in this project:
Back-end Developer
Back-end DeveloperContributions:610 commits in 2 years 7 months
Contributions summary:Witold's commits primarily focused on refactoring and improving the BIND 9 DNS server, specifically within the domain name system (DNS) server infrastructure. The changes involved cleaning up and refactoring code related to access control lists (ACLs), general network socket handling, and general low-level functionality like memory management. The user also worked on improving TCP connection handling and the operation of DNS zones, including ensuring that root zone mirrors are loaded correctly. The user's contributions demonstrate a focus on system-level programming in a networking context.
openedbind9dnsclosedbind
juju/juju
Mar 2017 - Nov 2018
Orchestration engine that enables the deployment, integration and lifecycle management of applications at any scale, on any infrastructure (Kubernetes or otherwise).
Role in this project:Back-end Developer
Back-end DeveloperContributions:166 commits, 79 PRs, 327 comments in 1 year 8 months
Contributions summary:Witold's primary contribution centers on refactoring and enhancing the `juju/juju` orchestration engine, specifically within the context of network configuration and related API functionality. The commits involve moving and restructuring the `NetworkConfigAPI` to improve the architecture and maintainability of the codebase. Further work includes integrating the `NetworkConfigAPI` with the `ProvisionerAPI` to enable the proper setting of container networking configurations. These changes suggest a focus on improving the handling of networking within the Juju orchestration system, demonstrating a focus on backend development.
operatormicroserviceyamljujuk8s
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