Facebook, Instagram and WhatsApp are now back up and running after being shuttered by a global outage on Monday.

The widespread disruption was blamed on a “faulty configuration change”, with Facebook saying in a statement: “Our engineering teams have learned that configuration changes on the backbone routers that coordinate network traffic between our data centres caused issues that interrupted this communication.

“This disruption to network traffic had a cascading effect on the way our data centres communicate, bringing our services to a halt.”

Here is a lookback at what has happened in previous tech outages and how the issues were resolved:

– July 22 2021

A number of websites including HSBC, ITV and Waitrose were affected by a brief outage.

Barclays, TSB, the Bank of Scotland, Tesco Bank and Sainsbury’s Bank were either entirely or partially inaccessible for a short period.

Airbnb, the PlayStation Network and Steam also experienced the temporary glitch, with some showing users a DNS error.

Reports at the time suggested the problem was linked to a performance product offered by Akamai, an American firm which began investigating the issue.

– June 8 2021

The Government’s website was among a range of websites affected by a major outage earlier this year.

The impact was also felt by notable media outlets including The Guardian and Independent, as well as the likes of Reddit, Amazon and Spotify.

It was linked to US firm Fastly, which helps speed up loading times by storing versions of a company’s website in local servers, meaning less data has to be transferred from long distances.

While some websites were knocked completely offline, others suffered image loading problems – including Twitter’s emojis – and news publishers were forced to use other platforms to report on the situation.

Fastly said the issues experienced were down to an “undiscovered software bug” in its system which was triggered by a single unnamed customer who updated their settings.

The firm said it managed to get 95% of the network operating back to normal within 49 minutes.

– December 14 2020

Google saw all its major apps, including YouTube and Gmail, go offline – leaving millions unable to access key services.

The company said the outage had occurred within its authentication system, which is used to log people into their accounts, due to an “internal storage quota issue”.

In an apology to its users, Google said the issue was resolved in under an hour.

– April 14 2019

It is not the first time Facebook-owned platforms have been affected by an outage, as a similar incident occurred over two years ago.

The hashtags #FacebookDown, #instagramdown and #whatsappdown were all trending worldwide on Twitter.

Many people ended up joking that they were relieved at least one popular social media platform was still working – in a similar way to what occurred on Monday evening.

A spokesman for Facebook at the time said: “Earlier today, some people may have experienced trouble connecting to the family of apps.

“The issue has since been resolved; we’re sorry for any inconvenience.”

– November 20 2018

Facebook and Instagram were also affected a few months prior, when users of both platforms reported being unable to open pages or sections on the apps.

Both acknowledged the matter but neither commented on the cause of the issue.