Meet an ISC Engineer - Tom Křı́žek!

Tom Křı́žek uses Arch, btw

Each quarter we like to profile one of our engineers, to acquaint our customers and users with some of the people they may interact with as they use our software. This time we’d like to introduce you to our newest staff member, Tom Křı́žek!

Tom joined our BIND 9 quality assurance team on May 1, so he’s still trying to get his head around everything at ISC. But he’s been happy to see that some of the open source tools he’s contributed to in the past are being utilized for BIND 9 testing.

He comes to us from CZ.NIC, where he contributed to many DNS-related projects such as Knot Resolver, DNS Shotgun, and respdiff. Before that, he worked for Red Hat, which he says was “a great place to learn how the open source model can work commercially and to see how open source communities operate.” Tom is a big proponent of free and open source software, and “by contributing to it professionally, I can really put my money where my mouth is.”

He has done a lot of DNS benchmarking that focused on the newer DNS-over-TLS and DNS-over-HTTPS protocols. He explains, “The switch from the stateless UDP to the stateful TCP has a lot of performance implications and I’ve spent quite a bit of time trying to understand them. It eventually led to the development of DNS Shotgun, which can be used for some really advanced benchmarks that excel at simulating real-world DoT and DoH traffic.”

Tom is pleased to join ISC and looks forward to further improving the tools he’s worked on in the past to better suit ISC’s use cases. He hopes to come up with new tools that could could improve the overall quality of BIND 9 and DNS software in general. He adds, “I see contributing to free and open source software as a way to give something back to the community, since I rely on the work of many other FOSS contributors in the software I use every day.”

He recognizes that the most challenging part of company-backed open source development is the business model, and he acknowledges that convincing people to pay for software that they can just run for free is difficult. As he says, “Providing the added value through support and documentation is critical to convince customers to actually pay for continued development. ISC seems to have this model just right.”

Tom holds a master’s degree in Information Technology from the Technical University of Liberec (Czechia). And he uses Arch btw.

Thank you for using ISC’s software and we hope you have enjoyed this peek behind the ISC curtain. We hope that sharing a little about us helps strengthen our connection to our customers. As always, we welcome your feedback at!

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