Grzegorz (Greg) Junka Last updated: 22June 2016
JavaScript and Erlang Consultant. A long track record of DevOps engineering and C++ programming.Overall 15-years' experience in full life cycle development of web, server, desktop and mobile applications.
Availability: immediately; present location: London, UK; nationality: Polish; aged: 40
Mobile: +44.795.808.2465; Phone: +44.207.277.2542; E-mail:
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Personal page; LinkedIn; Stack Overflow; Github accounts: yoonka, amiramix, builderl.
Programming Languages
JavaScript(2years); Erlang/OTP(4years); C++(6years); C(6months);ObjectiveC/iOS(9months); C#/.NET(2years); PHP(6months).
Front End and UI Development
- Practical knowledge of JavaScript and CSS frameworks and libraries: Dojo Toolkit (Dijit, dgrid), jQuery, React.js, Angular 2, Dust.js, Bootstrap, SASS/SCSS, Compass.
- Accessibility testing with WAI-ARIA, JAWS, NVDA; working with CMS systems: WordPress, Zotonic; implementing RESTful/JSON APIs.
- Experience using modern web standards: HTML5, CSS3, ECMAScript 6.
DevOps Engineering
- Build automation with Chef, CruiseControl.NET, Grunt, Dojo build system, Apache Ant, GNU make, custom scripts: escript, Bash, csh, ssh, Perl, PowerShell.
- Installing and maintaining production servers and testing environments on Debian, Red Hat, Ubuntu,Solaris, Open Solaris, FreeBSDand Windows Server.
- Configuring network services: HTTP/S(Nginx, Apache), DNS(Unbound), NFS, SMTP(sendmail, procmail), IMAP (dovecot),SSH, Samba.
- Practical experience with virtualization and Cloud environments: Microsoft Azure, AWS, Hyper-V, VirtualBox, Flexiant, VMware products, FreeBSD jail, ZFS volumes.
Software Design and Development
- Implementing protocols based on TCP/IP, UDP, JSON, XML, AT commands, BSD and IP sockets, and IPC techniques: signals, shared memory and semaphores.
- Designing, developing and testing native mobile and desktop applications on iPhone / iPad / iOS, Windows, Windows Phone, Windows Mobile and Symbian/UIQ.
- Integrating with external APIs: Facebook, Google Maps, Flurry, HockeyApp.
Project Analysis and Management
- Expertise in actor-oriented as well asobject-oriented analysis, design and development; working knowledge of design patternsandUML.
- Practical experience and in-depth knowledge of designing, implementing and optimising multi-threaded, client-server, distributed, and time-critical applications.
- Knowledge of Agile methodologies: Scrum (Rally), Kanban, XP, AUP, and ICONIX.
Education
2001 | Master's degree in Computer Science
University of Science and Technology in Kraków, Poland.
2000 | Participated in Andersen Consulting eCommerce Case Study
2nd place in group ranking.
2004 | Team management course
Learned how to be a better leader rather than a boss.
2005 | Mastering MFC Development Using Microsoft Visual C++
Creating advanced user interfaces using ATL, ActiveX, COM, and Windows API.
Jul 2007 – present| Consultant / Founder / Owner | Yoonka Ltd. | London, UK
As a Contractor / Consultant I have had the privilege to work with some of the brightest minds in the industry. Closely cooperating with teams at several first-rate companies I have gained practical experience solving problems using the right tools and methodologies.
I strive to always be on top of technologies used in Software and DevOps Engineering. Working on interesting personal projects is a great way of making it possible:
- Designing and implementingserver and web applications using Erlang and JavaScript: Erlang build tool, RDF database, CMS based on React.js and WebSockets.
- Studying Description Logic used in Semantic Web, learning OWL, RDF, OLAP, and Data warehouse concepts; writing documentation in DITA using Syntext Serna.
- Learning ReactJS, Angular 2, ECMAScript 6, C++11, C++14, MariaDB.
Skills: Erlang / OTP, C++, JavaScript, Git, DevOps, bash, sh, make, Pivotal Tracker.
Apr 2014 – Jan 2016| Erlang Developer | THBS / EE | Hatfield, UK
Torry Harris Business Solutions (THBS) provides software services to enterprise clients; EE (formerly Everything Everywhere) is the largest mobile network operator in the UK.
- Closely working with THBS staff on supporting the Policy Decision Function (PDF), a type of Policy and Charging Rules Function (PCRF) system at EE.
- Answering technical questions, fixing defects, reviewing code changes, writing technical documentation, developing and contributing to the design of new system features.
- Automating test cases using a testing framework based on Erlang Common Test.
* Developed and introduced a new build system with support for OTP-compliant release handling, later used to deploy PDF nodes to development, test and production.
* Refactored over 100 disparate Git branches into a set of new repositories and branches suitable to be managed according to the industry-recommended Git workflow models.
Skills: Erlang / OTP, Git, JIRA, Confluence, Trac, Erlang Common Test, DevOps, make.
Oct 2013 – Mar 2014| JavaScript Dojo Developer | HeathWallace Ltd. | Reading, UK
HeathWallace is an agency delivering experiences for some of the largest global brands.
- DevelopingDojo UI components using JavaScript / Dojo Toolkit, HTML5, and CSS.
- Implementing user interfaces with WAI-ARIA semantics and support for localization.
- Accessibility testing Dojo Dijit widgets using JAWS Screen Reader and NVDA.
- Testing and making necessary changes to support Android, iOS and Internet Explorer 8.
* Reimplemented a sticky menu to ensure its compatibility with supported devices.
* Refactored Dojo mixins used across widgets and classes to improve accessibility and support for internationalization, and to enable automated loading of JSON stub files.
Skills: JavaScript, Dojo Toolkit, Dijit widgets, Node.js, HTML5, CSS3, JAWS, NVDA, WAI-ARIA, JSON, Mercurial, accessibility testing.
Jul 2012 – Jul 2013| Full Stack Developer | Everything Everywhere | Hatfield, UK
Everything Everywhere (EE) is the largest mobile network operator in the UK.
- Full life cycle development and DevOps build automation of an Operation Maintenance and Configuration web application for a Policy Decision Function (PDF) system.
- Front end development of fluid web pages with Dojo / Dijit widgets (including dgrid from Sitepen), Bootstrap, and asynchronous client-side templates with Dust.js.
- Back end development ofRESTful API with Erlang / Zotonic CMS.
* Developed a complete releasing environment built on Node.js with minified CSS and JavaScript assets, AMD modules and local and embedded Erlang releases.
Skills: Erlang / OTP, JavaScript,Dojo Toolkit, Dijit widgets, dgrid, HTML5, CSS3, Bootstrap, Dust.js,Sass/Compass, Git, make, Node.js, JSON, PostgreSQL, Cygwin.
Jan 2012 – Jun 2012 | Senior Software Engineer | LoveThis | London, UK
LoveThis was a start-up with a mission to allow sharing recommendations privately.
- Principal developer of the iPhone LoveThis application reimplementing the initial application skeleton into a fully-functional version released to App Store.
- Extending the application with automatic TestFlight / HockeyApp crash reporting, Flurry analytics, Core Data migrations, and Facebook integration.
* Proposed and implemented a synchronization protocol which reduced the initial time needed by the application to load all required user data from the server by 80%.
Skills: Objective-C / iOS, Core Data, JSON, API, Ruby on Rails, Xcode, Git, OS X.
Jan 2011 – Sep 2011| Software Engineer | Penthera | Pittsburg, PA, USA / London, UK
Penthera's flagship product, Virtuoso, delivers high-quality media to mobile devices.
- Developing the native Virtuoso client applications on iPhone and Windows Phone.
* Proposed, designed and implemented a complete Erlang-based message-passing library for developing thread-safe concurrent applications on Windows Phone.
* Proposed the technology and delivered a complete performance testing environment able to stream the performance counter directly to a Zabbix monitoring server.
Skills: Objective-C / iOS, C# / .NET, Silverlight, Windows Phone, MVVM, Erlang / OTP.
Oct 2009 – Dec 2010| Software Development Engineer in Test (SDET) | Microsoft - Azure Infrastructure Europe | Dublin, Ireland
Part of a team responsible for moving CDN BI loggingsubsystem to Microsoft Azure.
- Writing test plans and specifications, automating test cases, reviewing software designs.
- DevOps approach to managingtesting environments composed of virtual images of production CDN servers running on Windows, Linux, FreeBSD and in Azure.
- Gained practical knowledge of designing, implementing and testing highly-available and scalable cloud applications that receive terabytes of data from thousands ofnodes.
Skills: C# / .NET, Microsoft Azure, PowerShell, Hyper-V, CDN, Visual Studio, Team Foundation Server (TFS), Source Depot, ContinuousIntegration-CruiseControl.NET.
Jul 2007 – Jan 2009| Symbian C++ Developer | Symbian – LPD | London, UK
Symbian Licensee Product Department (LPD) was providing professional services and expert consultancy to mobile phone vendors and software companies.
- Integrating, profiling and optimizing Symbian components on different phone baselines.
- Consulting arising problems with external customers, fixing and documenting defects.
- Reviewing design and code changes proposed by internal and external developers.
- Implementing and maintaining AT commands in etel/etelmm telephony tsy plugins.
- Porting a Linux console-based text editor written in C to Symbian P.I.P.S.
* Fixed the most defects on one of Symbian phone baselines; became a recognized expert in fixing defects where very little information is available, especially based on crash logs.
Skills: C++, C, AT commands, Symbian, Perforce, IBM Rational ClearQuest / ClearDDTS .
Jan 2006 – Jun 2007| Symbian C++ Developer | EMCC Software | Manchester, UK
The company was providing training and consultancy services to the mobile industry, including the world's leading handset manufactures: Nokia, Sony Ericsson and Motorola.
- Key developer responsible for the UI and internal components of a PIM push-email and calendar synchronization solution based on BlackBerry software.
- Collaborating with external teams,key customers, 3rd party vendors and the licensees during all stages of project life cycles; fixing defects; reviewing design and code changes; training younger members of the team; maintaining technical documentation.
Skills: C++, CodeWarrior, Perforce, ClearQuest, Nokia UIQ.
Jul 2006 – Sep 2006| Off-site project as Software Engineer | DataViz | Milford, CT, USA
DataViz is an industry leader in developing mobile office and productivity solutions.
- Involved in upgradingRoadSyncand extending it with a HTML viewer functionality.
Skills: C++, Visual Studio, Windows Mobile, ActiveSync push-email.
May 2002 – Dec 2005| C++ Developer / Team Leader | ITSoft | Kraków, Poland
Provider of a system to sell, reserve, and manage international coach tickets on-line.
- Leading projects aimed at enhancing system functionality; writing documents for project tasks andsystem designs; supporting other departments; familiarising new employees with company processes; leading seminars explaining the system architecture.
- Designing and implementing multi-threaded, distributed, and time-critical applications using TCP/IP, UDP, and IPC techniques: shared memory, signals, BSD sockets.
- Modelling and optimizing IBM DB2 embedded SQL procedures written in C.
* Designed the modular architecture of WWW pages and XML-based communication, and led a project that allowed embedding the pages within websites of external vendors.
* Consulted, designed, implemented and introduced a new Intranet in the company based on PHP, Smarty template engine, JavaScriptand MySql.
Skills: C++, STL, Valgrind, TCP/IP, UDP, IPC techniques, Red Hat, native Windows GUI, MFC, C, PHP, JavaScript, HTML, CSS, IBM DB2, MySQL,bison, flex, Xerces / ICU, CVS.
Aug – Nov 2005, Dec 2001 – Apr 2002| C# Developer | Kraków, Poland
Designing and implementing financial software to be used by cooperatives to manage houses and flats and to exchange invoices between financial systems.
Skills: C# / .NET, MS SQL 2000, WebServices.