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    Testing is doubting? Maybe, but it can avoid bugs with disastrous consequences, such as those we saw in 2021, which the companies concerned could have done without. 

    A button that doesn't work, a shopping cart that empties during the order process, an inability to log in to one's account: it doesn't take much to annoy a user and make him want to go to the competition. This is not only bad for the company in terms of image, because it makes it lose credibility and the trust of its customers, but it also directly affects the turnover. And sometimes, some bugs can even be much bigger than expected and cause a real bad buzz, even making the headlines in the media. Let's take a look at the biggest bugs of the year 2021. 


    Imagine, you have a TikTok account with thousands of followers and one morning, you log in and your followers have all disappeared. Panic, right? And that's exactly what happened on May 3, 2021. TikTok encountered a bug that displayed the wrong number of subscribers. Some users even ended up with their accounts blocked for no reason, while others simply had trouble accessing the app. 

    Of course, users did not wait to express their dismay on social networks. That day, the hashtag #TikTokDown quickly found itself in Top Tweet. Fortunately, TikTok was quite responsive and the bug was quickly corrected, but the frustration of users was there and the brand image of the social network suffered greatly. With automated tests, this situation could surely have been avoided, or at least detected before it became too big.  

    tik tok bug

    Call of Duty 

    In July 2021, Raven Software added a new feature to Call of Duty: Warzone that allowed players to choose and change their custom loadout in the pre-game lobby. However, players noticed a bug after the feature was rolled out. Some could enter matches already equipped with the best weapons and accessories, giving them an unfair advantage over others. 

    The addition of this new feature also triggered a bug that allowed players to suppress the sound of their footsteps. Raven Software had no choice but to remove this new feature, promising to re-enable it as soon as the bug was fixed. But something tells us that if non-regression tests had been done, there would not have been this problem.


    Another company that could have benefited from a non-regression test is none other than Tesla. Following an update that took place on October 23, 2021, the car company received numerous reports from customers that their cars had falsely identified forward collision threats that caused the automatic emergency braking system to activate and the vehicle to suddenly stop. 

    Tesla examined the reports and discovered a communication error in the 10.3 Full-Self Driving beta software. A rather dangerous bug, because in case of a sudden stop of the vehicle, the risk of rear-end collision and injuries is higher. The automaker quickly ordered a recall of the affected vehicles (about 12,000) and released a separate update to resolve the software bug.

    tesla bug 2021


    Four hours: that's how long the National Health Service (NHS) mobile app and website in England were down, preventing users from proving their COVID vaccination status. Many British passengers were stranded at airports, with some unable to board and others experiencing delays. This computer breakdown lasted only four hours but caused a lot of frustration and, according to many experts, highlighted the problems of a single centralized system. 

    Facebook, Instagram and WhatsApp 

    After TikTok, it was the turn of Facebook, Instagram and WhatsApp to crash and stir up the anger of its users, last October 4. During the whole evening, it was impossible to send or receive a message on these social networks. And if you typed Facebook on a search engine, the page was not found. 

    According to the American media outlet The Verge, it even took an emergency intervention in one of the data centers of the Facebook group to restore the service, which means that the fix could not be done remotely. The bug would be due to a change in the configuration of the routers coordinating traffic between the group's various data centers, which caused the services to stop. 

    facebook bug 2021


    Would you like to know that other people were able to access your bank account? No ? Yet that's what several LCL customers experienced on February 23, 2021. For an hour, a few hundred customers were able to access the accounts of other users of the bank's application. They could see expenses, savings amounts, different accounts, etc. Fortunately, it was not possible to perform transactions on the accounts whose data was displayed, nor was it possible to access the account holder's information, but this remains a critical incident. 

    The cause? Not a cyber attack as some people thought, but a technical bug linked to an update of the application. The mobile application had to be temporarily suspended until it was corrected. Not only did this bug impact customers whose accounts were accessible, but also customers who were unable to perform transactions during this time. Or how to damage the credibility of the company and the trust of the users...

    Automated tests to detect bugs faster!

    As we have seen in these different examples, sometimes it only takes one bug to paralyze an entire website or mobile application, with disastrous consequences on the image, reputation and credibility of the company, but also considerable financial losses. If you don't want to find yourself in one of these situations, you should detect bugs before your users notice them and report them. And for that, you have two complementary solutions. 

    The first is to put quality at the heart of your application, in order to detect the bugs that need to be corrected at the right time, i.e. before going into production. The second is to set up automated tests. This allows you to perform more tests, more frequently, and therefore to identify bugs faster in order to correct them more quickly, even before your users realize it or have time to complain about it.


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    404 error bug

    A bug on the app of the bank LCL, users could access the accounts of other customers - Le Parisien

    Facebook global outage: what happened? - Digital Century

    10 biggest software bugs and tech fails of 2021 - Testdevlab


    Screenshot 2022-07-06 at 16.18.40


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