Hi, I’m Matouš Dzivjak!
I work as a Staff Engineer at SumUp and do a lot of sports. The rest of my free time is spent on coding, friends, reading, cooking, and other stuff. This blog was started in 2019 to force myself into writing more and to have a place where I could share my thoughts and knowledge. Please take this whole site with grain of salt as my english is far from perfect, and I feel like creating a coherent piece of writing is still impossible task for me (I am working on it though).
Career
Staff Engineer @ SumUp, 5/2025 - now
Senior Software Engineer @ SumUp, 6/2021 - 5/2025
Working in the Platform Tribe - Identity Squad along with a 10 incredible teammates. The IAM (Identity & Access Management) team had its inception 2 months before I joined SumUp and we scale from 3 people drowning in incidents and work to 10 people in 2022 drowning only in work.
In the 3 years so far I have contributed to building a company-wide SSO (Single Sign-On) based on OIDC and OAuth2, authored a generic MFA (Multi-Factor Authentication) API that support recovery codes, TOTPs, SMS OTPs, webauthn credentials, and bootstrapped ReBAC-based access control system from RFC, to proof-of-concept, load testing, to adoption and general availability. Apart from the IAM related responsibilities I spend time on our public APIs, running an RFC forum, and Go and Rust guild.
Backend Developer @ Kiwi.com, 2/2019 - 5/2021
At Kiwi our team’s responsibility was developing core infrastructure and services with speed and maintainability as the primary goal. Our services served thousands of requests per second and served as the base for the transportation search engine. During my time at Kiwi I grew my experience and knowledge thanks to awesome team and mentorship from other skilled people in the company.
My contributions included initiating gRPC adoption across the company, helping build internal Go packages for cross-team usage, and developing multiple internal core APIs supporting search search functionality serving 100M request every day.
DevOps and Technical Support for Ads Systems @ FTV Prima, 9/2018 - 1/2019
Technical support for online platform advertisement team. Helping with every possible task at hand, so mostly scripting and data pipelines.Full-Stack Developer @ Techambition Ltd., 9/2017 - 5/2018
Full-stack developer (Node.js and React) of an online interactive tool for high school mathematics in a small startup.Projects
I enjoy programming outside the work as well and have build and still maintain a few personal projects:
- go-nanoid - Tiny Go package for generating URL friendly unique IDs.
- Mnemoname - tiny Go utility for generating mnemonic names.
- ezmail -
easy CLI utility for sending emails from terminal useful for scripts and people
that don’t want to set up the default
mailcommand that saves credentials into secure enclave. - dzxcodes - this website, using the Hugo framework.
- linkfix - a simple tool that helps you avoid the Link rot by reporting on no-longer working links in your files and suggesting replacements with Wayback Machine snapshots wherever possible.
- newz - News aggregator inspired by HN and Reddit written in python.
- godox - tool to extract specific comments from Go code based on keywords. Later integrated into the Golangci Lint.
- gosmtp - Go implementation of full-featured, lightweight and RFC compliant SMTP server.
I also contribute to a few open source projects: