Denis Dorozhkin, Developer in Moscow, Russia
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Denis Dorozhkin

Verified Expert  in Engineering

Back-end Developer

Location
Moscow, Russia
Toptal Member Since
May 28, 2021

Denis is a back-end developer with experience leading teams of up to six and working for enterprises (like Mail.ru Group)—specializing in high-load web development using Go and Python. Denis also excels at working with multiple systems for the management, consumption, and processing of big pipelines or data or handling a high number of requests. Thanks to a passion for performance optimization, Denis also knows quite a few algorithms. He's also comfortable with all modern web development tools.

Portfolio

TrafficStars
Go, PostgreSQL, ClickHouse, Apache Kafka
Mail.Ru Group
Go, Python, MySQL, ClickHouse, Tarantool
Proil
Django, PostgreSQL, Go, Redis, Celery, Python

Experience

Availability

Part-time

Preferred Environment

Go, SQL, Python, Docker, PostgreSQL, ClickHouse, Apache Kafka, Algorithms, Linux

The most amazing...

...experience was leading a team in the build of a system consuming 500,000 RPS while also decreasing the system's memory consumption by more than 1TB.

Work Experience

High-load Team Lead

2020 - 2021
TrafficStars
  • Led a team in the development of the international AD platform for Trafficstars.com.
  • Accepted and processed over 500,000 AD RPS which reduced the necessary system memory (by 1TB) and the CPU usage.
  • Implemented real-time user data changes using Kafka Streams which decreased overspending by 80%.
  • Developed complex money bidding auction algorithms which helped with effective cost prediction.
  • Worked on advanced microservice and database architecture planning.
  • Implemented a raw SQL financial data analysis using ClickHouse and PostgreSQL.
Technologies: Go, PostgreSQL, ClickHouse, Apache Kafka

MyTarget Team Lead

2018 - 2020
Mail.Ru Group
  • Led a team in the development of an advertisement network platform for Target.my.com.
  • Worked on statistics aggregation and fault tolerance which sped up the statistics retrieval by 30%.
  • Developed a high-load zero-latency profile retriever daemon in Kubernetes.
  • Optimized the database architecture using ClickHouse.
  • Built data-driven binlog parsers and uploaders with data processing pipelines.
  • Implemented Hadoop MapReduce jobs for data aggregation and comparison.
Technologies: Go, Python, MySQL, ClickHouse, Tarantool

Senior Back-end Software Engineer

2018 - 2018
Proil
  • Contributed to the development of a mobile oil delivery service for Proil.moscow (B2B and B2C).
  • Implemented an asynchronous driver status microservice with the Google Maps API.
  • Developed multiple DRF-style APIs for the operator, promo codes, orders, and others.
  • Sped up the service by queueing hard requests using Celery with Redis.
Technologies: Django, PostgreSQL, Go, Redis, Celery, Python

Social Network Software Engineer

2015 - 2018
Mail.ru Group
  • Contributed to the development of a major Russian social network, My.mail.ru vk.com.
  • Developed a feature to import music from other networks along with storage and deduplication.
  • Implemented news updates, profile settings, and photo storage upgrades.
  • Contributed to the development of various features like mailers, car fines, money operation microservices, and a multiproxy engine.
Technologies: Go, Perl, Lua, C++, PostgreSQL, Tarantool, ClickHouse, Python, Microservices

Education Project

I built the web back end and infrastructure of an edtech project analog to Coursera. It started as a small startup in Russia and we aimed to make a platform that will help students prepare for exams. We added multiple different education and content features for online preparation during the COVID-19 pandemic.

Open-source Projects

https://github.com/mailru/go-clickhouse
I like to commit to open-source projects. I also maintain Go libraries.

• ClickHouse Database Driver Written in Go: https://github.com/mailru/go-clickhouse
• Database Query Builder for PostgreSQL, MySQL, ClickHouse, and SQLite: https://github.com/mailru/dbr

Languages

Go, SQL, Python, Python 3, Perl, Lua, C++, GraphQL

Frameworks

Django, gRPC

Tools

GitLab CI/CD, GitHub, GitLab, NGINX, Docker Compose, Celery, RabbitMQ, Ansible, Helm

Paradigms

Microservices, Agile, REST, Concurrent Programming, Microservices Architecture

Platforms

Apache Kafka, Linux, Web, Docker, Kubernetes

Storage

PostgreSQL, Amazon S3 (AWS S3), ClickHouse, Redis, MySQL, Aerospike, Couchbase, Tarantool, Memcached

Other

High-load, Data Structures, OOP Designs, Patterns, System Design, CI/CD Pipelines, Advertising, Advertising Technology (Adtech), Algorithms, NATS, Team Management, Team Leadership, Remote Team Leadership, Apache Cassandra, Education Technology (Edtech), Fintech, Consul, MinIO

Industry Expertise

Trading Systems

2014 - 2018

Bachelor's Degree in Computer Science

Moscow State University - Moscow, Russia

NOVEMBER 2020 - PRESENT

Problem Solving (Basic) Certificate

HackerRank

APRIL 2019 - PRESENT

Golang Web Service Development Part 2 (Credential ID PYLHRCQ8PNYM)

Coursera

DECEMBER 2018 - PRESENT

Writing Web Services in Python (Credential ID 6HJJ42EVMXP2)

Coursera

NOVEMBER 2018 - PRESENT

Go Web Service Development (Credential ID DDCKYN3P65ZG)

Coursera

OCTOBER 2018 - PRESENT

OOP and Programming Patterns in Python (Credential ID 4AP47R6ZNJ5J)

Coursera

DECEMBER 2017 - PRESENT

Python Programming (Credential ID FQ2GQA2G84JU)

Coursera

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