After setting their feet on the ground somewhere on the continent of Africa and testing its Android app, a group of Facebook engineers and product managers determined there was much work to be done for the company's social network to work for everyone across all platforms.

The excursion was reportedly part of a companywide effort to make Facebook's mobile platform its top priority. On June 19, engineer Alex Sourov released a blog post on the findings revealed by the group's trip.

"We purchased several different Android handsets to test the latest version of the Facebook app -- and the testing process proved to be difficult," stated Sourov. "The combination of an intermittent, low-bandwidth network connection and a lack of memory space on the devices resulted in slow load times and constant crashes. We even burned through our monthly data plans in 40 minutes."

After returning to their home bases, the group determined Facebook's mobile division needed to work on four areas for emerging markets: mobile performance, data efficiency, network reliability and application size. The changes reduced start time and data use by 50 percent.

Realizing the Facebook app overwhelmed mobile devices that had single-core processors, the group determined it needed to streamline the way the app's features loaded. The features would attempt to all load at once, creating a bottleneck at the mobile device's processor.

On the front of data efficiency, the team decided to implement WebP. The compression format reduced the size of images by up to 35 percent, when compared with the widely used and revered JPG format.

The team optimized the resolution of images, making them more suitable for display on mobile devices and conserved the amount of data they consumed on delivery -- before, the max resolution was used. They also reworked the caching of images, so that photos could be recalled more often without have to re-download them.

The Facebook team rolled out the OKHttp on the Android app, an open-source protocol that Sourov said cut down slow or stalled images by close to 90 percent in 2013.

The trip to Africa resulted in the Android app losing a significant amount of weight, reduced in size by 45 percent by Sourov's calculations.

"The most popular mobile devices in Africa have little disk space available, which is a significant barrier to installing app upgrades," stated Sourov. "This means that people in developing countries often use older versions of the app that don't have up-to-date features or take advantage of the improvements described in this blog post."

Sourov said the mobile team in London worked with application programming kits (APKs) available for each version of the Android OS to ensure that users of the Facebook app have only what's required to run the app on their device. That eliminates the download of unnecessary APKs when installing the Facebook app.

While the excursion team has already rolled out some new features for the Facebook app, Sourov said there were more to come. He said Facebook planned to continue to work to improve the Facebook experience in emerging markets.