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Igor Ostriz

Igor Ostriz

Member since April 26, 2012
Igor is a lead iOS developer with several years of experience programming fault-tolerant systems ranging from working with telecoms to building systems that monitor radioactive emissions. He has worked with a broad range of technologies and also took lead roles as an architect.
Igor is now available for hire
  • C, 20 years
  • C++, 13 years
  • C#, 10 years
  • Python, 5 years
  • JavaScript, 4 years
  • iOS, 3 years
  • Objective-C, 3 years
  • Ruby, 1 year
Preferred Environment
Xcode, Sublime, TextMate, MS VS, Git, Mercurial
The most amazing...
...things I've built is a Management system for the Croatian State Office for Nuclear Security (DZNS).
  • Lead iOS Developer
    2013 - PRESENT
    StalkDocs (via Toptal)
    • Application for Sales Representatives that helps them sharing information among themselves.
    • Users can have access to the public information (like global accounts and customers).
    • Users can be organized into teams, that can share information.
    • Information is shared on "per item" basis, allowing teammates to share only selected piece of data.
    • Backend was residing on Parse. Payments via AppStore and Stripe.
    Technologies: Objective-C, Parse, JavaScript
  • iOS Developer
    2012 - 2013
    Chromatic (via Toptal)
    • Chromatik exists to help musicians have a great experience practicing and performing music using digital tools.
    • They are able to access their sheet music and their practice markings (annotations) on many different devices, and their practice sessions will always be in-sync and up-to-date across those devices. That means that sheet music, annotations, and recordings will be synchronized from web-to-iPad and from iPad- to-web and even from iPad-to-iPad.
    • Further more, musician can make a recording and share it with rest of the orchestra (or just a director).
    • Backend is developed using NodeJS and MongoDB, using CoffeeScript.
    • Client is Web and iPad.
    Technologies: Objective-C, CoffeeScript
  • Lead iOS Developer
    2012 - 2013
    Pictrition (via Toptal)
    • Social networking application promoting health through nourishing positive eating habits (
    • Heavily customized GUI, targeted mainly for iOS6, with lots of beautiful graphic, charts, photos...
    • Integrated with Facebook and Twitter. Social gaming with awards.
    • Backend was developed with Sinatra Ruby hanging on MongoDB.
    • Hosting was Heroku, MongoHQ and Cloudinary for pictures.
    Technologies: Objective-C
  • iOS Developer
    2012 - 2012
    Confidential Client (via Toptal)
    • iPad project made for popular notebook application. Request was to develop wrist protection area that could be freely sized, for the purpose of protecting drawing canvas from unwanted wrist touches while painting on a screen.
    • Other part of a request was to develop zoom control that would enable drawing (mostly writing with finger or stylus) on an enlarged area located on the wrist guard that represents small portion of the line on a notebook paper. Automatic movement of a satellite (small portion on the paper) to the right while writing, advancing to the next row, scrolling of paper canvas, snapping to the predefined rows for easy positioning...
    • Several approaches were tested during development of this project: OpenGLES 1 and 2, touch event forwarding (unfortunately achievable only by private API).
    • At the end, the best results were achieved by using plain Quartz drawing subsystem for zooming. Similar applications were studied during this process (Noteshelf, Notabillity). The result is comparable/better than competitive products.
    Technologies: Objective-C, OpenGLES 2
  • iOS Developer
    2012 - 2012
    Circa (via Toptal)
    • Challenge was to develop custom page curl animation without using Apple private API that would prevent successful app submission to AppStore.
    • Task was to achieve 60fps curl animation that would allow great UX.
    • A lot of OpenGLES 2 research was done.
    • Result was a small library that would curl any UIView, and that view remained interactive during curling.
    • A couple of long standing publicly known issues regarding ios should be overridden (e.g. CADisplayLink mysteriously drops fps to 40, request was to have clean 60 on iPhone 3gs)
    Technologies: Objective-C, OpenGLES 2
  • Lead Developer
    2012 - 2012
    bitmoji/Future Instruments (via Toptal)
    • Developed proof of concept/demo for Slidewall application.
    • Slidewall application is used as an interactive projection of photos, videos and notes called Slideas.
    • Slideas are displayed and organized on the SlideWall by a team or group of people to create, edit and share ideas in real-time from anywhere utilizing Cloud technologies.
    Technologies: Java (, Objective-C, Python
  • ASP MVC Developer
    2011 - 2012
    Hamilton Fraser Insurance Company (UK)
    • Complex online management of tenancy deposits (used by landlords, tenants and agencies), support of online payments, property data management, dispute resolution, complex reporting, importing of property and tenancy external data, complex queries and administrative tasks, and payment detection through parsing of banking data exchange formats.
    • MVC 3 with SQL Server backend.
    Technologies: C#
  • Lead Developer
    2009 - 2010
    ANPR Parking system
    • Parking management system with plate recognition. System consists of entry/exit IP cameras that constantly broadcast image to the central server.
    • Server detects motion in particular part of the image and reads plate (OCR). Based on data the ramp automatically rises (or not).
    • Technology: server part (RNPR – RecroNetPlateRecognizer) is a Windows service developed in C# (Nevron GUI toolkit) for the system administration purposes and handling the configuration of the cameras, image hot spots and so on.
    • Another (independent part) is ASP.NET server for the user/plates administration, billing.
    • This server communicates with RNPR server through REST (XML and JSON). MS SQL as the backend database.
    • Project architect and lead development in the team of 5.
    Technologies: ASP.NET, REST, XML, JSON, MSSQL
  • Lead Developer
    2008 - 2009
    DZNS - NMS
    • Management system for the Croatian State Office for Nuclear Security (DZNS). Server collects data from all radiologic stations throughout the country. Comparing results to the acceptable thresholds, and alerting if attention is needed.
    • Web server as the presentation layer.
    • Lead development in the team of 3.
    Technologies: Python, Django HTML, JavaScript
  • Lead Developer
    2008 - 2008
    Offline Charging
    • Mediation for the offline charging (for the largest Telco operator in Croatia, T-Com), collecting CDR data (Customer Data Records) from the Diameter server, and preparing them for further analysis.
    • Speed and robustness was a major concern.
    • Led development in the team of 3.
    Technologies: Python
  • Lead Developer
    2005 - 2007
    OT Viewer
    • CDR BI for one of our Telco operators (Optima Telecom d.o.o.). Consists of server application (data retrieval from the DW – Oracle 9i), and client application for viewing, analyzing, summarizing and printing bills as a convenience GUI app for end users – customers.
    • This client application is distributed to the clients/customers of Optima Telecom.
    • Technology: system was developed using combined Python/Oracle9i (server part) and standalone exe application (C++, MFC/BCG).
    • Team of 5 people, involved as chief architect/lead developer.
    Technologies: Python, Oralce9i, C++, MFC/BCG
  • Web Developer
    2005 - 2005
    • Risk Assessment Analysis for INA Naftaplin (largest oil company in Croatia).
    • System was developed in cooperation with the University (FER) and Enconet d.o.o. Involved 3 Risk Assessment methodologies, What-If, FMEA and HAZOP.
    • VB6 project front-end for EncoRA, C# for the SIGURA (WinForms).
    • Access database as the back-end.
    • Led development of team of 3.
    Technologies: VB6, C#
  • Classkick (Development)

    One of the “awesomest” app for helping teachers communicate everyday school tasks with students in a fun way.
    Teacher has an iPad and he monitors all the work students are doing in real time. Students can get immediate attention (by rising a virtual hand)
    Involved as a system architect and a lead developer in a team of 6.
    Backend is Firebase.

  • Languages
    C++, C#, Objective-C, C, Ruby, JavaScript, Python, Visual Basic
  • Frameworks
    Cocoa, Boost, WPF, Cocos2d, Ruby on Rails (RoR), Django
  • Libraries/APIs
    WTL, Microsoft Foundation Class Library (MFC), wxWidgets
  • Platforms
    Windows, iOS, Mac OS
  • Tools
    InstallShield, Adobe Photoshop
  • Paradigms
    Concurrent Programming, Functional Programming, Agile Software Development
  • Storage
    SQLite, Microsoft SQL Server, MongoDB, PostgreSQL
  • Other
  • Master's degree in Computer Science
    1993 - 1993
    University of Zagreb - Zagreb, Croatia
  • Masters degree in Compute Engineering
    1987 - 1992
    Faculty of Electrical Engineering and Computing, Zagreb, Croatia
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