Sergii Zagriichuk

Sergii Zagriichuk

Ukraine
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Sergii Zagriichuk

Sergii Zagriichuk

Ukraine
Member since October 15, 2012
Senior Java Developer with proven ability to create architecture and develop efficient, scalable and fault-tolerant solutions for complex tasks.
Sergii is now available for hire
Portfolio
Experience
  • Java, 11 years
  • JUnit, 11 years
  • Guava, 4 years
  • XML, 7 years
  • SQL, 5 years
  • HTML5, 4 years
  • C#, 3 years
  • Android, 2 years
Ukraine
Availability
Part-time
Preferred Environment
Windows, Mac OS X, Linux, Intellj IDEA, Git
The most amazing...
...I've developed is a solution for storing data in distributed environment with possibility to connect to any node for getting all information and data.
Employment
  • Principal Developer/Java Architect
    Playtika
    2013 - PRESENT
    • Designed new vision of game server architecture based on micromodules.
    • Implemented micromodules architecture on the game core.
    • Developed reels generator, analyzer and calculator modules.
    • After profiling and refactoring main flow algorithm of “Slotomania” product, application performance increased by 40%.
    • Introduced and instituted consistent use of gitflow in the company.
    Technologies: Java, Spring, Guice, Multithreading, Collections, Hight Load ,Distributed Systems
  • Java Architect
    DataCradle
    2011 - 2013
    • Project: DataCradle-Cloud is cutting-edge technology of the cloud to deliver unlimited data storage with built-in data protection and provisioning, radically simplifying data storage and protection for business and home.
    • Analyzed issues from customer.
    • Designed software architecture.
    • Developed common architecture using OSGI (Eclipse Gemini, Spring DM).
    • Worked on development of module for storing data.
    • Developed module for manage data.
    • Built architecture/modules for high load perform data.
    • Developed module for communication between client and server based on the Netty framework.
    • Worked on communication/serialization protocol using Google Protocol Buffer.
    • Made secure module, for authentication/authorization clients on the cloud.
    • Building of client virtual file system based on the FUSE driver.
    • Developed Android prototypes for Cloud Storage systems.
    Technologies: Multithreading, Collections, JSE, JEE, TCP/IP, NIO, Netty, Google Protocol Buffer, Eclipse Gemini, Spring 3, OSGI, Android
  • Senior Java Developed
    (Undisclosed Company)
    2011 - 2012
    • Android app for the banking business
    • Android app for the business task scheduling
    Technologies: Java, XML, Android, SQL
  • Senior Java Developer
    UBS
    2011 - 2011
    • Project:CSL, This project is multi-modular Java server based application for analyzing financial market/received transaction/enrich/make reports and so on.
    • Analyzed issues from customers.
    • Designed software architecture.
    • Developed module for received transaction.
    • Worked on the logic for enrich transaction.
    • Built several Database Queries and Stored Procedures.
    Technologies: Multithreading, Collections, Java Core, JMS, TCP/IP, XML, HTML, JavaScript, SQL
  • Technical Leader
    NICE Systems
    2009 - 2011
    • Project:NICE Bridge, This project is Client/Server application based on .NET WCF Duplex technology. It provides for customers functionality to monitor Record on Demand events on the NICE Perform System.
    • Analyzed issues from customer.
    • Created functional specifications of the application.
    • Designed software architecture.
    • Created webservices in duplex mode using WCF.
    • Developed module for support SSL in application.
    • Created client for show pop-up windows followed play sound.
    • Created Installation and User Manual guides.
    • Developed DataBase structures, Queries, Stored Procedures, Views and Triggers.
    • Managed team of 5 developers
    Technologies: Multithreading, Collections, Java and .NET Core, TCP/IP, HTML, XML, JavaScript, SQL
  • Senior Java Developer
    Epam Systems
    2008 - 2009
    • Project:BFIX, This project is Client/Server application based on Java (Core, Multithreading, TCP/IP, XML),FIX (Financial Information eXchange) and FAST (FIX Adapted for STreaming) protocols.
    • Analyzed functional specifications and requirements of the application.
    • Designed software architecture based on specifications and user requirements
    • Designed and Developed FIX validation module to check FIX messages in run- time.
    • Created XMLBinding module to serialize xml templates/dictionaries into java objects in run- time.
    • Created FASTEngine module for encodes and decodes FIX messages into FAST messages and back again.
    Technologies: Multithreading, Collections, Java Core, NIO, TCP/IP, FIX and FAST protocols
  • Java Developer
    Aricent
    2003 - 2008
    • Project:Dictaphone PowerScribe Workstation, Web Client/Server health care speech recognition system which lets physicians dictate, self-complete recognized text,and electronically sign reports from any Internet-connected PC, giving radiologists"once-and-done"controloverthe report creation process.
    • Analyzed functional specifications and requirements of the application.
    • Designed software architecture based on specifications and user requirements.
    • Designed and implemented of Login Module for access by Dictation Client of Power Scribe and integration with existing C++ActiveX objects.
    • Designed and developed of Order Entry and Coding Manager Modules.
    • Designed and implemented of Login Module for access by Administrator, OrderEntry, CodingManager Clients.
    • Designed and implemented of VisitEntry Module.
    • Developed Stored Procedures, Views for MS SQL database.
    • Developed module to load data from HL7 parse and provides to other modules.
    • Developed Webservices using frameworks Axis 1.4 and Axis 2.
    • Designed and implemented building process using Apache Ant 1.6.
    Technologies: Multithreading, Collections, Java Core, Swing, XML, Spring, Servlets, HL7, SQL
Experience
  • DataCradle (Development)
    http://datacradle.com/

    DataCradle-Cloud is cutting-edge technology of the cloud to deliver unlimited data storage with built-in data protection and provisioning, radically simplifying data storage and protection for business and home.

  • NICE Systems (Development)
    http://www.nice.com/

    NICE Bridge, This project is Client/Server application based on .NET WCF Duplex technology. It provides for customers functionality to monitor Record on Demand events on the NICE Perform System.

Skills
  • Languages
    Java, HTML5, XML, Scala, SQL, C#
  • Frameworks
    Spring, JUnit, Google Protocol Buffer, Eclipse Gemini, OSGi, Netty
  • Libraries/APIs
    Java Collections, Guava
  • Paradigms
    Agile Software Development, Waterfall development, Concurrent Programming, Object-oriented Programming (OOP), Test-driven Development (TDD)
  • Platforms
    Java EE, Windows, Linux, Mac OS X, Android
  • Storage
    MS SQL, MySQL, Neo4J, Cassandra, Oracle
  • Misc
    Apache Commons
Education
  • Bachelor and Master Degrees degree in Faculty of Information Technology and Computer Engineering
    Kiev National Technical University - Kiev
    1999 - 2004
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