Mikhail Ryzhov. Software Developer.

email: rymiser@gmail.com www: github.com/rymis LinkedIn: Mikhail Ryzhov  address: Brno, Czech Republic

About

I've been the Senior Software Developer in Kiwi.com since July 2018. And that is what I have done:

• Optimized data flow between data generation service and flight search engine so dataset loading time decreased from around 10 minutes to less than 2 seconds and freshness of the data from 3 hours to just 10 minutes.
• Optimized memory usage of the flights search engine decreasing k8s request by 30%
• Developed fast and easy to use CatBoost evaluation library: github.com/kiwicom/catboost-cxx" (article)
• Worked on a prices prediction engines development using Machine Learning technologies. (TensorFlow, CatBoost, XGBoost)
• Developed Ground Routing engine in C++ using Google Transfer Patterns algorithm with optimizations.
• Started rewriting and refactoring flights search engine frontend from Python to Go.

In the year 2019 I was sixth in Telegram voice call quality measuring contest.

I used to work in Yandex LLC in Moscow as a Senior C++ developer in Yandex.Images search quality and base search runtime team. I worked on:

• Optimizing the base search daemon so it became 40% faster by adding an additional filtering stage.
• Preparing data in MapReduce system and training Neural Network for new factor based on text embeddings.
• Working on some other factors for the ranking formula.

Also I used to work in R-Alpha and Kurchatov's Institute. There I was a part of the team developing a custom operating system with strong cryptography mechanisms based on FreeBSD and cross-platform IPSec implementation in userspace using GObject/GIo.

Skills

• Languages: C, C++, Go, Python, UNIX shell, awk, JavaScript
• Tools: make, autotools, cmake, gdb, valgrind, docker
• ML tools: TensorFlow, CatBoost, numpy
• VCS: Git, cvs, Subversion, Mercurial
• Technologies: Backend development, Networks, Big data, Machine Learning
• Human languages: Russian (native), English, Czech.

Experience

• Since July 2018 Kiwi.com. Senior C++ Developer in the Search Backend group.
  • Worked on dataflow optimizations for flight search engine, that allowed to decrease time from data coming to a database to frontend from 3 hours to 10 minutes.
  • Worked on memory optimizations in flight search daemon using memory alignments, variable precision types, and LZ4 based compressed data storages.
  • Developed CatBoost model evaluation library in C++ catboost-cxx (article)
  • Created infrastructure for training CatBoost Gradient Boosting model for prices prediction based on historical data. Tested tens of different models based on TensorFlow, CatBoost, dlib, XGBoost.
  • Developed very fast timezone data manipulation library based on tz.js which allows to operate with local times in ground search engine. Here you can find it.
  • Wrote prototype of flights search and ground search integration.
  • Developed real-time ground routing search engine using Google's transfer patterns which is running in production.
  • I've developed prototype of the flights search entry-point daemon rewritten from Python to Go with code refactoring. Now it is in production.
• October 2016 - June 2018 Yandex. Senior C++ Developer in the Images search quality group.
  • Developed code for MapReduce and runtime calculation of several new NeuralNet based ranking factors
  • Increased base search daemon RPS by 45% by implementing additional ranking stage with specialized factors used to train Gradient Boosting formula
  • I'm a part of the team which works on replacing old index types with the universal and fast new ones
  • Implemented fast DotProduct/L1Distance/L2Distance libraries that could be found in tens of Yandex products, for example they are in use in CatBoost open source gradient boosting library
• 2006-2016 National Research Center Kurchatov Institute and R-Alpha. Senior Software Developer.
  • Worked on fast asynchronous socket I/O implementation for software VPN solution that allowed to work on 1Gbit bandwidth with strong encryption. (It was in the year 2014, so 1Gbit on CPU was a miracle)
  • Developed userspace components of custom FreeBSD-based operating system e.g. installer, certificate generation/revocation/accounting tool,...
  • Used to be maintainer and developer of software PKCS#11 token implementation which could be found at atoken.sf.net
  • Developed low-level drivers for Smart Cards
  • I was writing code for cryptographic network tunnels and PKI utilities

Education

1999-2005 Moscow Aviation Institute. Application Mathematics and Physics

While learning in MAI I used to be a part of the Mathematics Olympic team and won Moscow group Olympics between technical universities twice and was second in personal accounting in Russian Olympics between technical universities.

Hobby

I like to solve mathematics and programming problems. Also I like riding the bicycle, tracking in mountains, juggling, playing pool and so on. I really like music and playing guitar. Also I like 3D printing and modeling things in CADs.

I'm the member of projecteuler.net and has result:

The last version of this CV can always be found at rymis.eu.org/cv.html