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Denys Sinyakov, Java Developer in San Francisco, CA, United States
Denys Sinyakov

Java Developer in San Francisco, CA, United States

Member since February 27, 2015
Denys is a seasoned software engineer, engineering manager, and entrepreneur with over 11 years of experience. He specializes in distributed and scalable web applications targeted to run in the cloud. Has a track record of using diverse programming languages and technologies with Java being a favorite one. Since the start of his career, he has been an advocate for readable, maintainable, and testable code.
Denys is now available for hire

Portfolio

  • Cisco Systems
    Java, JavaScript, Go, Python, Spring, Ruby, Jersey, Docker, AWS, Kafka...
  • Max2 (via Toptal)
    Java, Kafka, Scala, Play Framework, Akka, Redis, MySQL
  • BSDvm
    Java, PHP, Python, AngularJS, Play!, Apache Thrift, ZeroMQ, Akka, HTML, CSS...

Experience

  • Java, 10 years
  • Docker, 5 years
  • NoSQL, 5 years
  • Spring, 3 years
  • AWS ECS, 3 years
  • Algorithmic Trading, 3 years
  • Natural Language Processing (NLP), 2 years
San Francisco, CA, United States

Availability

Part-time

Preferred Environment

IntelliJ IDEA, Git, MacOS, AWS, Linux, Docker

The most amazing...

...thing I've coded was a MapReduce that could process and modify the data of more than a billion records in less than 10 minutes.

Employment

  • Senior Software Engineer

    2015 - PRESENT
    Cisco Systems
    • Built an API gateway and data processing/aggregation microservices using Springboot for a distributed monitoring solution.
    • Made key contributions to the design and implementation of a Java auth framework based on Oauth2.
    • Implemented a project management system on top of Openstack API.
    • Increased stability and security of an open sourced monitoring Ruby-based agent by refactoring and implementing the authentication layer.
    • Boosted performance of the data ingestion service by 60% by analyzing code with profiling tools and fixing identified issues (decreased auth overhead, optimized payload processing).
    • Implemented product licensing capabilities in monitoring solution by building middle-tier services and integrating with licensing service.
    Technologies: Java, JavaScript, Go, Python, Spring, Ruby, Jersey, Docker, AWS, Kafka, Elasticsearch, Redis, Postgres, Apache Avro, Apache Mesos, MongoDB, AMQP, Openstack
  • Java Developer

    2015 - 2016
    Max2 (via Toptal)
    • Hardened mobile app Java back-end API security by introducing a signed request feature (Amazon API like).
    • Boosted performance of API back-end pagination requests by 50% by implementing Redis-based pagination.
    • Increased the robustness of the API by introducing JSON schema and automated payload field validations.
    • Made code more reliable and testable by refactoring and applying testability best practices.
    Technologies: Java, Kafka, Scala, Play Framework, Akka, Redis, MySQL
  • Founder and Lead Developer

    2014 - 2015
    BSDvm
    • Designed and implemented a VPS infrastructure orchestration layer in Python.
    • Built a cloud provisioning system based on a custom work queue implemented with Java and Akka.io.
    • Designed and implemented a cloud control panel with PHP and AngularJS.
    • Built integration with Amazon AWS via Java API.
    • Created the main company website.
    Technologies: Java, PHP, Python, AngularJS, Play!, Apache Thrift, ZeroMQ, Akka, HTML, CSS, VMware, Amazon AWS
  • Engineering Manager

    2012 - 2014
    Google (via EPAM)
    • Implemented a number of BI system plug­ins for proprietary file systems, databases, and data warehouses.
    • Designed and implemented a web application that served as a meta­data dictionary for the data delivered to multiple data warehouses.
    Technologies: Java, JavaScript, AngularJS, GWT, HTML, CSS, Protocol Buffers
  • Software Engineer

    2011 - 2012
    Google (via EPAM)
    • Developed a multi-­purpose Java query tool based on MapReduce.
    • Participated in the migration of the application from a MySQL to a NoSQL database.
    Technologies: Java, Python, JavaScript
  • Software Engineer

    2010 - 2011
    Google (via EPAM)
    • Implemented a GWT front­-end framework that served as the basis for application development for a CRM administration application.
    • Implemented a quick search feature that improved the UX.
    • Re­-engineered the application's mail queue administration view.
    • Covered the application functionality with functional automated tests.
    Technologies: Java, GWT, Python, Protocol Buffers, MapReduce, MySQL, NoSQL
  • Software Test Engineer

    2006 - 2010
    GlobalLogic
    • Developed a testing framework in Java/Selenium for a web application.
    • Created a number of JavaScript extensions for the Java/Selenium testing framework.
    • Wrote a parser in Perl that helped to fix thousands of legacy automated tests written in Tcl.
    Technologies: Java, Python, Perl, JavaScript, WebDriver, Selenium

Experience

  • Java Quant/algorithmic Trading Framework (Development)

    The framework is implemented based on Interactive Brokers Java API and open sourced back-testing engine. Allows to easily implement new trading strategies and backtest them, using historical data from multiple sources: Interactive Brokers API, Yahoo Finance API, Database, CSV files.

  • Albumica (Development)

    A web application that allows for sharing of photo albums across multiple social networks. Technologies used include Facebook API, Instagram API, VK API, AngularJS, Redis, and Play!

  • GammaCloud (Development)

    Developed a PaaS for PHP, RoR, Python, and Java app deployment. Technologies used include Go!, Ruby on Rails, MongoDB, and Docker.

  • Building Modern Web Applications with AngularJS and Play Framework (Publication)
    Building robust web applications is often a lot about choosing the right tools. Doing so with a combination of tools that ensure both a modern, flexible front-end, and a solid, reliable back-end is something everybody wants. This article demonstrates exactly that trick by combining AngularJS and Play Framework to build a simple blog application.

Skills

  • Languages

    Java, Python, Go, CSS3, PHP, JavaScript, HTML5, SQL
  • Frameworks

    Spring, Play Framework, AngularJS, Jersey, Bootstrap 3, Apache Thrift, Django
  • Libraries/APIs

    Interactive Brokers' API, ZeroMQ, Instagram API, Facebook API, jQuery
  • Tools

    AWS ECS, Mesos, Amazon Virtual Private Cloud (VPC), IntelliJ IDEA, Git, VirtualBox, VMware, Vagrant
  • Platforms

    Docker, Linux, AWS Lambda, AWS EC2, FreeBSD, MacOS
  • Other

    Algorithmic Trading, Quantitative Finance, Natural Language Processing (NLP), Protocol Buffers
  • Paradigms

    Agile Software Development, MapReduce
  • Storage

    NoSQL, MongoDB, MySQL, H2, PostgreSQL, Redis

Education

  • Master of Science degree in Radio Electronics Engineering
    1999 - 2004
    Khmelnitsky National University - Ukraine
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