Software engineers are the mighty guardians of keeping Google up and running 24/7. In a report written on Wired, Google uses three words in explaining how it stays up: Site Reliability Engineering. According to the report and Google's own numbers, in 2015, Google's App Suite - which includes Gmail, Google Docs, Google Drive et al - were up 99.97 percent of the year. 

The Vice President of Engineering at Google, Ben Treynor Sloss, said, "The result of our approach is that we end up with a team of people who will quickly become bored by performing tasks by hand and have the skill set necessary to write software to replace their previously manual work." 

Site reliability engineers are up for more hires around the world due to site maintenance that exists in the world due to the chance of a site being a victim of cyber-crime or just general maintenance that keeps the website functioning with all of its bells and whistles. 

One of the site reliability engineers at Google, Andrew Widdowson detailing what its like to be an SRE - as it is abbreviated - said, "Our work is like being a part of the world's most intense pit crew. We change the tires of a race car as it's going 100mph." 

The team that works for Google has worked with a publisher to release a textbook that is now available for purchase named Site Reliability Engineering: How Google Runs Production Systems

Here's an application form to be a Software Engineer for Google.