Nikolai Golub, Software Developer in Amsterdam, Netherlands
Nikolai Golub

Software Developer in Amsterdam, Netherlands

Member since December 28, 2014
Nikolai is a self-directed and organized professional. He is a results-oriented problem solver with sharp analytical abilities and excellent communication skills. He is a highly competent software engineer with four years of experience in Python programming and web technologies.
Nikolai is now available for hire

Portfolio

Experience

Location

Amsterdam, Netherlands

Availability

Part-time

Preferred Environment

Vim Text Editor, MacOS, Linux, IntelliJ

The most amazing...

...application I've built uses Django to store performance test results, involving millions of metrics and integration with systems and APIs like Jira and Zabbix.

Employment

  • Software Developer

    2017 - PRESENT
    Booking.com
    • Reduced cancellations related customer support tickets by 20% by implementing a set of A/B experiments.
    • Improved performance of entrepreneurial partners by integrating cancellation policy recommendation model.
    • Completed full API integration with tours and activities providers, which increased transactions by 10%.
    • Contributed to community-driven projects, including Python libraries and developer tools.
    Technologies: Cassandra, Apache Kafka, Kubernetes, MySQL, Perl, Java
  • Software Developer

    2015 - PRESENT
    EverCharge (via Toptal)
    • Introduced database schema migration using alembic and Flask-Migrate.
    • Developed web portal from scratch using Flask-Admin.
    • Introduced automated tests, including unit, integration, and Selenium-based tests. Improved coverage to 90% of the Python codebase.
    • Developed customer signup flow, which includes handling of Stripe payments.
    • Developed a customer dashboard.
    • Decreased the cost of monthly billing procedures by moving it from Freshbooks to Stripe.
    • Automated the reimbursement procedure, including issuing a lob.com check.
    • Configured deployments on AWS Elastic Beanstalk using Docker.
    • Created a set of tools for validating data from devices.
    Technologies: Celery, Redis, Stripe, SQLAlchemy, Flask
  • Front-end Developer

    2016 - 2017
    Staffmatch (via Toptal)
    • Implemented vector animation for the main website.
    • Added automated tests for core web logic.
    • Refactored UI logic, which reduced the number of bugs.
    Technologies: Webpack, Redux, React.js
  • Python Web Developer

    2015 - 2015
    Walkio (via Toptal)
    • Added features that allow customers to communicate via Twilio SMS.
    • Migrated the data model to remove logical inconsistencies.
    • Added integration with Checkr.io for background checks on prospective dog walkers.
    • Set up a two-step sign-up for dog walkers.
    • Added an editing page for account details and billing information.
    • Increased unit test coverage from 0 to 87 percent and included Selenium tests.
    Technologies: Twilio, Stripe, PostgreSQL, Django
  • Python Test Automation Developer

    2014 - 2015
    Positive Technologies
    • Created a Python module for generating data for load testing using Yandex.Tank.
    • Created a software for advanced test artifact collecting. Facilitated analysis of new bugs.
    • Implemented an abstraction layer for simpler web UI testing. Reduced the support cost of tests.
    • Moved auxiliary services to the Docker. Decreased resource usage of the test environment.
    Technologies: GitLab, Elasticsearch, MongoDB, Docker, Python
  • Performance Engineer

    2012 - 2014
    Dino Systems
    • Suggested, designed, and developed a web portal for aggregation performance tests results. Reduced time spent on report creation by 30%. Used Django, PostgreSQL, Celery, and amCharts.
    • Created a cross-platform desktop application for tracking time for Jira issues. Improved time tracking accuracy significantly.
    • Developed performance tests for a SOAP API service using C#.
    • Designed and developed advanced performance tests for a telephony system.
    • Developed a script for creating test cases in a test case management system from real HTTP traffic.
    Technologies: Celery, Django, Subversion (SVN), R, AmCharts, jQuery, Python, C#
  • Performance Engineer

    2011 - 2012
    Devexperts
    • Developed a script for automatic collection and result processing of performance tests. Decreased the number of human errors and data losses.
    • Designed and successfully ran performance tests for an industrial monitoring system on a tight schedule.
    • Set up an environment for monitoring and collecting results in Amazon EC2.
    • Introduced an advanced configuration of a monitoring system. Reduced the load to the monitoring system MySQL database and improved performance.
    • Performed a migration to a new OS testing images in Amazon EC2.
    Technologies: AWS EC2, MySQL, Subversion (SVN), Linux, Java

Experience

  • PyJTT (Development)
    https://github.com/citizen-stig/pyjtt

    A desktop application for tracking time in Atlassian JIRA.

  • KidStat (Development)

    A web application that provides categorization of child growth standards, using world health organization data. It is built on top of Flask, MongoDB and React. Source code is available on GitHub: https://github.com/citizen-stig/kidstat.

  • Performance Dashboard (Development)

    A Django-based dashboard for storing and analyzing performance test results.

  • Single Page about the Marathon in Saint Petersburg (Development)

    It uses MongoDB for storing data and amCharts for representing it.

    It uses Babel for multi-language support.

    Sources: https://github.com/citizen-stig/ergo_white_nights

  • Log Trimmer (Development)
    https://github.com/citizen-stig/logtrimmer

    A script that allows users to cut off part of the log file using 2 timestamps. It uses binary search, so it's efficient even on large log files.

  • Python Best Practices and Tips by Toptal Developers (Publication)
    This resource contains a collection of Python best practices and Python tips provided by our Toptal network members.

Skills

  • Languages

    Python 3, Python, JavaScript, Java, SQL, Bash, HTML, C#, R, ECMAScript (ES6), CSS, Rust, Perl
  • Frameworks

    Flask, Django, Bootstrap, Redux, Bootstrap 3, JUnit
  • Tools

    PyCharm, Jira, JSX, Celery, GitHub, IntelliJ IDEA, Nginx, Jenkins, Zabbix, Git, GitLab, Subversion (SVN), IntelliJ, Vim Text Editor, Babel, Webpack, Mocha, VirtualBox, Maven, Grafana
  • Paradigms

    Automated Testing, Database Design, Object-oriented Programming (OOP), Unit Testing, Continuous Integration (CI), Test-driven Development (TDD), Asynchronous Programming, Concurrent Programming, REST
  • Platforms

    Amazon Web Services (AWS), Linux, Docker, AWS EC2, Twilio, MacOS, Mailgun, Heroku, Kubernetes, Apache Kafka
  • Other

    Performance Analysis, Performance Optimization, Full-stack, Data Migration, HTTPS, HTTP, Performance, RESTful APIs, Front-end, Back-end, Ajax, APIs, AmCharts, React.js, Cryptography, i18n, Freshbooks, Networks, Network Programming, A/B Testing
  • Libraries/APIs

    PyMongo, React, SQLAlchemy, Stripe, jQuery, Stripe API, Chai, Twilio API, Mailchimp API
  • Storage

    NoSQL, Redis, MongoDB, MySQL, PostgreSQL, Elasticsearch, Cassandra
  • Industry Expertise

    Security

Education

  • Master's degree in Management and Technology for Information Security
    2006 - 2012
    Saint-Petersburg State University (Information Technologies, Mechanics, and Optics) - Saint Petersburg

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