Mat Byczkowski
Tech Lead at Block
San Francisco, California, United States
Summary
🤩
Rockstar🎓
Top SchoolMat Byczkowski is a Tech Lead and seasoned security engineer with 12 years of experience building identity, credential, and access systems that secure large-scale infrastructure. Currently leading identity infrastructure at Block, he has a track record of rescuing troubled projects and delivering complex, high-impact systems—most notably architecting Tap to Pay security and a SPIFFE-based workload identity service that enabled cloud migration and was presented at KubeCon. Comfortable across backend, DevOps, and platform engineering, he contributed to notable open-source projects like Square’s Keywhiz (secrets distribution) and certstrap, improving build pipelines and hardening dependencies. Based in San Francisco, Mat combines hands-on implementation with strategic architecture and an appetite for pragmatic fixes that make systems reliably secure in production.
12 years of coding experience
11 years of employment as a software developer
Bachelor’s Degree Computer Science, Bachelor’s Degree Computer Science at The University of Edinburgh
Polish, English
Stackoverflow
861reputation
25kreached
13answers
1question
encryption
top-5%
Github Skills (37)
docker10
ssl10
bootstrap10
secret-management10
server-configuration10
dockers10
java10
dropwizard10
javas10
certificate10
go10
certificate-authority10
bootstra10
testing9
cicd9
Programming languages (11)
Github contributions (5)
square/certstrap
Jun 2019 - Jul 2022
Tools to bootstrap CAs, certificate requests, and signed certificates.
Role in this project:
Backend Developer
Backend DeveloperContributions:4 releases, 11 reviews, 30 commits in 3 years 1 month
Contributions summary:Mat focused on enhancing the `certstrap` tool, specifically improving its functionality for managing certificates and keys. Their contributions included allowing users to override default file inputs and outputs for certificate requests and signing. Furthermore, they automated the injection of version information into the binaries during the build process, and cleaned up tests, fixing issues surfaced by static analysis tools. These changes suggest a focus on improving usability and build processes within the tool.
golangcertificate-authoritysslsignedtls
square/keywhiz
Oct 2018 - Jul 2022
A system for distributing and managing secrets
Role in this project:Back-end & DevOps Engineer
Back-end & DevOps EngineerContributions:3 releases, 102 reviews, 322 commits in 3 years 9 months
Contributions summary:Mat primarily focused on improving the Keywhiz server and its associated infrastructure. They updated dependencies to address security vulnerabilities, including upgrading Jackson and Dropwizard. The user also implemented changes to ensure the Docker image builds correctly and included version reporting, reflecting a DevOps contribution. Additionally, they modified code related to keystore paths and other server configurations.
golangkeywhizmanage-secretssecret-managementsecurity
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