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Serokell company is mentioned among the top developers 2020.

Serokell Gets Listed As Top App Developer

We already have a small tradition to announce the mentions of Serokell among the top developers. Today, we got listed on one more independent software development platform – [TopAppDevelopers.com](https://topappdevelopmentcompanies.com/ee/directory/app-developers/estonia). 

Our success would not be possible without our loyal customers. We would like to thank all of you for supporting our work with your valuable feedback and reviews.

Serokell Among Top App Developers

Serokell at ZHF Hackathon

Last Friday, some of Serokellers participated in a hackathon in Moscow. Read about the hackathon and their experience in the article.

Last Friday, some of Serokellers participated in a semi-physical [Zero Hydra Failure Hackathon](https://nixhax.github.io/zhf-21.11/index.en.html) in [undefspace](https://undef.club/#about), Moscow.

![event attendants](/files/w2/w2p5yba2.5ef5b309d40d414bbc1dbdeeed5d4cb19cdfbfde.jpeg)

Together with other attendants, we managed to push more 6 PRs in less than 8 hours and fix a lot more packages (due to a fix of  `openjfx` by our site reliability engineer Alexander Bantyev). 

![yx0ymu17.IMG_20211120_004153.jpg](/files/yx/yx0ymu17.IMG_20211120_004153.jpg)

If you want to learn more about the event, you can read a short writeup on the [NixOS Discourse](https://discourse.nixos.org/t/zhf-hackathon-celebration-event/16079/5).

Daniel Rogozin's Paper Released in the Journal of Logic and Computation

Recently, a paper of one of our employees was released in the Journal of Logic and Computation. Read more details about the paper in this article.

D.Rogozin's Paper Released in Journal of Logic and Computation

Last year, Daniel Rogozin participated in a conference called Logical Foundations of Computer Science (Miami, USA, 2020). The contribution was the conference paper and lecture on the computational interpretation of some intuitionistic modal logics. [For more info, check this brief report about the conference](https://serokell.io/blog/lcfs-2020).

The extended paper has been recently released in the Journal of Logic and Computation (Oxford University Press). [The previous article](https://link.springer.com/chapter/10.1007/978-3-030-36755-8_15) was about questions related to syntax. In other words, Daniel was considering the modal typed lambda calculus based on the curious system of intuitionistic modal logic where he proved such properties as confluence and strong normalization.

The extended paper covers a broader class of topics. In addition to syntax, Daniel also proposed semantic analysis of those intuitionistic modal logics. In this paper, he proved that the obtained modal lambda calculus is complete with respect to cartesian closed categories equipped with coalgebras obtained from the monoidal endofunctor. That provides essential categorical intuition for evaluation in this type theory.

Additionally, he analyzed a class of logics by means of Kripke-Joyal semantics. This kind of semantics arose from topos theory and generalisation of the underlying topological notions proposed by Grothendieck. The modalities might be interpreted as prenuclear operators used in point-free topology. This version of topology studies topological spaces as lattices of open neighbourhoods without mentioning geometric points. As Newton said: “if I have seen further, it is by standing on the shoulders of Giants”. This aphorism illustrates the paper since this part of the article develops [Robert Goldblatt's ideas](https://academic.oup.com/logcom/article-abstract/21/6/1035/945244).

The paper [is available online](https://academic.oup.com/logcom/advance-article-abstract/doi/10.1093/logcom/exaa082/6049830), and it is to appear in the special issue of the Journal of Logic and Computation prepared by Sergei Artemov (City University of New York) and Anil Nerode (Cornell University).

Serokell at NixCon 2020

On October 16-18, we participated in NixCon 2020. Here's the details of our participation.

On October 16-18, we participated in NixCon 2020. 

NixCon is an annual conference for contributors and users of [Nix](https://serokell.io/blog/what-is-nix) and NixOS. 

It’s an event we keep participating in every year, [including the previous one](https://serokell.io/blog/serokell-nixcon2019). This year, due to the COVID crisis, it was done remotely. 

One of our employees, Alexander Bantyev, participated with a talk on Nix flakes in production, a thing we have been working for some time now. 

If you’re interested, here’s the talk. You can also see all the other talks of the event on their YouTube channel. 

<iframe width="560" height="315" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen="" data-src="https://www.youtube.com/embed/7sQa04olUA0?start=9117"></iframe>

Viktor Kazanski

Denis Oleynikov

Pavel Golovin

Mika Logan

Constantine Ter-Matevosian

Alexey Danilevsky

Vladimir Serov

Nikolay Yakimov

Inna Logunova

Ivan Smetannikov

Aleksandr Pak

Leonid Vasilev

Ilya Lubimov

Andrey Borzenkov

Markus Barenhoff

Kirill Kizilov

Kristina Martin

Nurlan Alkuatov

Jay Zelenskyi

Adrián Enríquez

Anton Sorokin

Uliana Sushinskaia

Vadym Salnyk

Daniel Kazantsev

Vito Canadi

Chris Höppner

Lars Jellema

Yorick van Pelt

Yegor Timoshenko

George Agapov

Kirill Andreev

Brian Kean

Val Baturin

Kyrill Briantsev

John Burnham

Ivan Dolgakov

Kirill Elagin

Pavel Gliev

Joakim Goldkuhl

Ivan Gromakovsky

Kostya Ivanov

Murat Kasimov

Alexander Rukin

Vasiliy Kevroletin

Mikhail Kilianovski

Maxim Koltsov

Dmitry Kovanikov

Artem Kuznetsov

Nikita Lisitsa

Allan Lukwago

Dmitry Mukhutdinov

Alexander Nikolaev

Dmitry Nikulin

Konstantin Andriotis

Artem Ohanjanyan

Ilya Peresadin

Pasquale Pinto

Danya Rogozin

Rinat Stryungis

Alexander Tiunov

Paul Tsupikoff

Mitchell Vitez

Josef Vlach

Mikhail Volkhov

Murad Murzaev

Vladislav Zavialov

Arseniy Seroka

Jons Mostovojs

Felix Stegerman

Roman Melnikov

Jaroslav Shadrin

Marina Sharygina

Leonid Cupikov

Ping Chen

Sergey Litovchenko

Nadir Asanbekov

Dmitry Lifanov

test1

Domagoj Cerjan

Ellina Poponnikova

Dmitrii Susloparov

Damir Garifullin

Aleksandr Pakulev

Kirill Kuvshinov

Roman Alterman

Anton Dobrenkiy

Alexandra Voicehovska

Eduard Sachava

Sandeep Chandrika

Grigory Pevnev

Artem Velychko

Olga Bolgurtseva

Yulia Gavrilova

Zhenya Vinogradov

Alexander Bantyev

Stepan Prudnikov

Moremi Vannak

Fedor Fedorov

Krisztián Ádám

Alyona Antonova

Artem Yurchenko

Diogo Castro

Heitor Toledo Lassarote de Paula

Ilona Prikule

Natalya Kokova

Daria Smirnova

Serokell PR

Gints Dreimanis

Ivan Markov

Andrey Demidenko

Dmitriy Mozhevitin

Iurii Kravchenko

Vlad Shcherbina

Preetham Gujjula

Dina Safullina

Alexey Khaciyants

Dmitri Puzyrev