Since last October 24, 2020, Facebook forces applications to show Instagram photos with an authentication token. This change in Facebook is part of a strategy to increase the security of its platform.

This change generated an increase in the time of the application process that allows displaying an Instagram image. This time has an impact on application load times.

In case of displaying only one or a few images on the screen, this process time is not very significant, and a good user experience is preserved when loading the application. But if the application screen must show many images at the same time, the sum of all the processing times of the Instagram images results in a very slow page load, and consequently might generate a bad user experience.

The solution to this technological challenge is to use cache systems. The cache system allows you to temporarily save the Instagram image, without the need to request it from Instagram again. However, if an image is not cached, it must first be requested from Instagram.

In the list of participants of a promotion, up to 1,000 participants are displayed at a time. For this reason, only the photos of Instagram participants that are already in the cache system are displayed. If they are not yet in the cache, the administrator can generate it at that time, through the link indicated in the following image:

Once a photo has been cached, it will be displayed directly for the next 24 hours.

How does it work in the public photo gallery of the contest?
In the public photo galleries of the participants, between 20 and 30 images are displayed on the screen. This number of images is low, and it allows to maintain a good user experience. It is for this reason that the cached photos will be displayed directly in the gallery, and in the case of photos that are not cached, they will be automatically generated at that time. As there are few images, the user experience is good.

When an image has been cached, it remains for 24 hours visible. In this way, the following visits to the gallery of participants will always have a fast page load, since all the images will have been cached.
The images that are cached in the public gallery will also appear cached in the organizer's internal list of participants.