Mrežni Sistemi
Mrežni Sistemi is a software development company based in Belgrade, Serbia. Our field of work is needs analysis, design and development of web based applications. We specialize in delivering robust, industry-strength content management systems which power large and well-visited Web sites. As the name of the company suggests (English: Networking systems), we focus professionally on data distribution techniques and solutions.
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The craftsmen
Our dev team has 11 full time developers, and four associates. We firmly believe in the principle of outsourcing, and outsource ourselves all the non-development tasks (including, and of course not limited to, graphic development, system administration, book-keeping...)
Members of our development team have years of practical, hands-on experience in the fields of informational systems design, programming and databases. Our professional involvement with World Wide Web and sites with back-end functionality dates back to 1996, when Internet in Serbia was in its earliest infancy, and virtually all web sites were static, brochure-like publications that under-utilize the potential of the media. Since then, we are constantly improving our understanding of the Web and possibilities that it provides. We consider this pioneering spirit to be one of our greatest assets.
See our office photo stream at Flickr.
The tools of our trade
Mrеžni Sistemi adopted the strategy of focusing on one web platform, gaining exhaustive knowledge and understanding of it, rather than diversifying and trying to cover as much of the technology as possible.
Our platform of choice is PHP / MySQL. PHP has proven to be a reliable, wide-spread and ever evolving product. It powers numerous sites, and more importantly – it is the technology basis of some of the largest Internet movers: Yahoo, Facebook, and Wikipedia, to name a few.
For larger scale projects, we follow the Model-View-Controller design paradigm, either by building upon the Zend framework, or through custom implementation (for truly specific requirements). If the project is somewhat less than ground-breaking, it can gain a flying start with our Document Concentrator CMS, which is a custom Presentation-Abstraction-Control implementation.
On the client side, we intensively use Dynamic HTML and AJAX mechanisms, jQuery and YUI frameworks. Our team leader actively participates in the community that plans the development of jQuery, so we have a considerable understanding of the platform and its direction (as opposed to casual “google – download – recycle” approach).
To lesser extent, we also participate in the communities surrounding MySQL, as well as some forum, blog and user interface Open Source projects.
How we lose sleep
Content management systems developed by Mrežni Sistemi have a long track record of stability and good performance.
Our biggest installation to this day, the B92.net web site, demonstrates the robustness and good performance of our solution. It delivers an average of one million web pages per day, operating on a single (albeit powerful) server computer.
Another installation, the Big Brother web site, handled the visit (caused by the unexpected event in the show) peeking at 1.2 millions of pages without a glitch. We address the issue of stability most seriously, and our designs attempt to “expect the unexpected” and deliver even in the extreme exploitation conditions.
Scalability is the crucial design aspect for media-intensive web services. For music-on-demand portal B92.fm we use balanced application servers, and independent media servers to deliver audio. Current setup totals 11 server computers, and the growth is possible in multiple directions – app serving, media serving, database and session handling.
Excellent security record proves that our efforts in that direction were successful. We utilize the standard security mechanisms of the platform and/or additional access restrictions.
Selected references
B92.fm – http://www.b92.fm
The concept of B92.fm is a blend of social networking site and radio-on-demand. Backed by the strong audio production of radio B92 and their huge music library, this site offers visitors to hand-picks the music numbers they want to hear, or to publish music, enjoy playlists from other users, explore similar music, discover artists.
Architecture of the site is truly scalable, with load balancing and fail-over mechanisms that address both the growth of visit, and possible geographical dispersion of hosting. Since B92.fm is serving media, the bandwidth and load calculations are one level above the “normal” website, and scalability factor has a whole new meaning.
The site is also connected to a number of other media providers, such as YouTube and Flickr. Users manipulate the content stored by these providers through Media Library of B92.fm, never leaving our site and not aware of the underlying communication.
User interface is a mix of Flash and DHTML, and makes heavy use of jQuery and AJAX.
EKorpa – http://www.ekorpa.com
E-commerce arrived late in Serbia – in year 2008 the first payment processor began offering its services. Mrezni Sistemi took part in design, and were later awarded the development of the general-purpose shopping mall on the Web, operated by a local company and offering the goods from local suppliers. Obviously, the first model was amazon.com, but the design team introduced a number of fresh and locally-specific ideas.
The application sports the custom MVC architecture, and database replication is the primary means of scaling up. The system automatically interfaces with a number of other systems - supplier warehouses, delivery services, customer care system etc.
User interface is DHTML based, and makes heavy use of jQuery and AJAX.
B92.net – http://www.b92.net
The biggest Serbian news portal, comparable to BBC in local term, is eight years worth effort of B92 staff and Mrežni Sistemi. Mrezni Sistemi did not just take part in this project - we are the sole author of architecture, design and development.
The circumstances required some smart technical solutions, and through relentless optimizations we managed well over 1 million page views per day on just one server computer – which also hosted the editorial and admin panels. Recently, the resources were increased, but so have the features of the portal and the visit.
Other references
The full reference list is available upon request.
Contact
Mrežni Sistemi
Tel 011 328 6241 Fax 011 328 6159
Strahinića Bana 39, Beograd, Srbija 
