Yulij Andreevich Lesov, Developer in Kowloon Bay, Hong Kong
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Yulij Andreevich Lesov

Verified Expert  in Engineering

Software Developer

Location
Kowloon Bay, Hong Kong
Toptal Member Since
November 23, 2016

Yulij is a fast-learning polyglot developer with a keen business sense. He has distinguished himself with each of his clients by resonating with the business needs behind each project: being able to make judgments not only for the best technical solution, but also the one that makes the most business sense.

Portfolio

SafeT
Networking, HTTP, Transmission Control Protocol (TCP), Ember.js, Ruby
SafeT
C#, Knockout (Knockout.js), Networking, HTTP...
FreshUp
Docker, Ansible, Sh, C++, Redis, Cassandra, RabbitMQ, Socket.IO, Express.js...

Experience

Availability

Part-time

Preferred Environment

Vi, Git, Linux

The most amazing...

...thing I've built--from firmware, custom protocol transfer, and server to web/mobile front-end--is a system for vending machine monitoring and data analytics.

Work Experience

Developer

2017 - 2019
SafeT
  • Maintained a legacy product in Ember.js.
  • Developed an administration panel fronting product.
  • Consulted on network security.
  • Created a testing framework bridging between developers and QA team.
  • Fielded end-user calls as technical support.
Technologies: Networking, HTTP, Transmission Control Protocol (TCP), Ember.js, Ruby

Developer

2016 - 2016
SafeT
  • Engineered raw network protocols.
  • Created an enterprise network security proxy product.
  • Developed horizontal scaling with performance tuning.
  • Wrote a domain-specific language for the user development kit.
Technologies: C#, Knockout (Knockout.js), Networking, HTTP, Transmission Control Protocol (TCP), Ruby

Technical Lead

2014 - 2016
FreshUp
  • Integrated contactless payment in vending machines.
  • Created data analytics with statistical modeling.
  • Built an embedded C++ system.
  • Developed a Rails/Ember web front end.
  • Programmed a Node.js general-purpose processing server.
  • Implemented a corporate ERP.
  • Facilitated Ansible/Docker mass deployment.
Technologies: Docker, Ansible, Sh, C++, Redis, Cassandra, RabbitMQ, Socket.IO, Express.js, Node.js, Ember.js, Ruby on Rails (RoR)

Developer

2014 - 2016
Hong Kong Jockey Club
  • Built an embedded system for payment gateway integration in vending machines.
  • Implemented core logic in Node.
  • Utilized C++ for accessing machine protocol.
  • Facilitated Ansible/Docker mass deployment.
Technologies: Docker, Ansible, Socket.IO, REST, PostgreSQL, Ruby on Rails (RoR), Bootstrap, AngularJS, Express.js, Node.js

Developer

2014 - 2016
Hong Kong Polytechnic University
  • Built a university smartcard access control system.
  • Created core logic in Node.
  • Developed the driver layer in C#.
  • Deployed in Windows with networking security.
Technologies: Bash, C#, Socket.IO, SQLite, CoffeeScript, Express.js, Node.js

Senior Developer

2014 - 2014
LRN
  • Built a subscription-based e-course platform with a corporate website.
  • Created the core platform in Node/Angular.
  • Implemented Solr indexed materials search.
  • Integrated a legacy system.
Technologies: Amazon Web Services (AWS), Memcached, Redis, Solr, REST, MySQL, Python, AngularJS, Express.js, Node.js

Senior Developer

2013 - 2014
FacilityTeam
  • Created a building management enterprise platform.
  • Implemented a Node/Angular app.
  • Balanced feature requests, code stability, and project velocity, transitioning from ex-PM.
Technologies: Amazon Web Services (AWS), Redis, PostgreSQL, Python, AngularJS, Express.js, Node.js

Testing Limits and Capabilities of the Node.js/Express.js Stack

This codebase is a personal proof-of-concept project to test the limits and capabilities of the Node.js/Express.js stack in producing a full-feature but modular production back end. I have showcased both full-feature and abstraction layers in this codebase.

EXAMPLES
A messenger layer: Designed to enable modular components written in any language to be used. These allow taking advantage of developing a module using the best tools, i.e., languages, frameworks, or libraries, suited for the task at hand while still being able to use them together in the stack.

Pseudo-cron: A cron-worker stack in Node.js, designed as a proof of concept. The design pattern has been borrowed from Java/PHP-like factory-worker patterns with dependency injections but written in the Node.js interface.

The rest includes:

• Full ES6 compilation via Babel to ensure stability
• Libraries that I wrote for interacting with Cassandra, handling migration, and using in projects
• HTTP routing as a service
• Cassandra as NoSQL datastore
• Some Google Maps API integration
• Bootstrap + SASS stylesheets
• Node-config
• Logging

Languages

Sass, ECMAScript (ES6), CoffeeScript, CSS3, Emblem, Pug, Haml, Sh, Bash, CSS, HTML, Java, PHP, HTML5, JavaScript, Ruby, Python, C, C++, Perl, Less, C#, Batch

Frameworks

Bootstrap, AngularJS, Ember.js, Slim, Express.js, Ruby on Rails (RoR), Compass, ZURB Foundation, Knockout (Knockout.js), Zend Framework, Twig, Sails.js, Laravel

Libraries/APIs

SockJS, Socket.IO, Handlebars, Node.js, jQuery, Bookshelf.js, React, Mustache, Sidekiq, RxJava, Butterknife

Tools

RabbitMQ, Zsh, Git, NPM, Cluster, Bundler, NGINX, Ansible, Solr, Capistrano, Grunt, Google Kubernetes Engine (GKE), Subversion (SVN), Gradle, Composer

Paradigms

Behavior-driven Development (BDD), REST, Test-driven Development (TDD)

Platforms

Docker, Kubernetes, Linux, Amazon Web Services (AWS), Meteor, Magento, osCommerce

Storage

PostgreSQL, Cassandra, SQLite, MySQL, Elasticsearch, MongoDB, Redis, Memcached

Other

WebSockets, HTTP, Gatsby, Transmission Control Protocol (TCP), HAProxy, Network Protocols, Vi, Networking

2009 - 2012

Bachelor of Business Administration Degree in Business Administration

The Chinese University of Hong Kong - Hong Kong

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