Our greatest challenge was transfering the data from the old site to the new. Due to the big difference in the CMS version between the old portal and the new one and due to some addons that were installed on the old site, we were unable to use the API in order to transfer the articles. So we opted for a more direct approach and we added directly to the database, after ensuring its integrity.
The second issue we faced were the time constraints. Since while transfering the data the site couldn't be updated with new content, we put in the manhours and completed the project in record time.
Finally, since it was a very successful site with lots of ads, we had to design in such a way so that the ads will fit seamlessly with the content without annoying the user. So, we created positions for the ads in places where they would break the monotony of the text and we introduced movement to grab the eye.