#Start-upSpotlight is a new series on Information Age, shining a light on Australian start-ups disrupting the status quo.

Rather than despair after missing out on his dream job at Amazon, Ryan Kroonenburg recognised an online training opportunity which has grown from an Aussie start-up to the world's largest cloud computing school with more than a quarter of a million students across six continents.

A former immigration lawyer with self-taught IT skills, Kroonenburg worked his way up to solutions architect at Rackspace and then moved around the industry before setting his heart on a job at Amazon Web Services (AWS). With classroom-based training prohibitively expensive, he scoured the web for AWS resources and studied hard – only to fall short at the final round of Amazon's three-month application process.

The silver lining was that he had identified a dearth of online education and training resources for cloud computing professionals. A Cloud Guru was born, with Kroonenburg offering his first course via online learning marketplace Udemy.

As the business grew, Ryan brought his brother Sam onboard and migrated A Cloud Guru across to a custom platform of his own design. Today recognised by cloud computing giants Amazon, Microsoft and Google, the site offers courses to help professionals prepare for a range of cloud computing certifications, along with deep dive courses on cloud technologies.

While traditional AWS training options can cost thousands of dollars and are mostly delivered in a classroom, A Cloud Guru has disrupted the sector by providing on-demand training modules starting at US$15.

The platform's serverless architecture is built on AWS Lambda, ensuring A Cloud Guru's only pays for the compute time consumed by users of the site. This model allowed the business to avoid growing pains and easily scale as it experienced rapid organic growth – quickly attracting a loyal following through social media and word of mouth within the developer and IT operations community.

Tapping into this online community has been one of the keys to A Cloud Guru's success, Kroonenburg says. To kickstart the first course on Udemy, he gave away 200 free subscriptions on Reddit. Later the brothers founded ServerlessConf, which has run in New York, Austin, London and Tokyo focusing on sharing experiences building applications using serverless architectures.

"This community has been the cornerstone of A Cloud Guru," Ryan Kroonenburg says. "It's not just about having a strong customer base; for a start-up, a strong community is about having that continual feedback from passionate people to ensure you're staying on the right track and meeting the changing needs of your customers."

After self-funding A Cloud Guru for two years, the Kroonenburg brothers recently secured US$7 million investment from Boston-based Elephant Venture Capital. The flexibility to hold off on external funding until now gave the start-up the freedom to find its own way, Sam Kroonenburg says.

A Cloud Guru already has staff based in Melbourne, London, Washington DC and Austin, with the new funding earmarked for a sales and marketing team to help to fuel US growth. The site also intends to expand beyond AWS certification-prep courses to cover Google Cloud Platform and Microsoft Azure.

"Starting out with a serverless technology platform ensured we were profitable from the beginning, but more importantly it meant we didn't have to seek investors too early and risk choosing the wrong path for the business," Sam Kroonenburg says.

"We turned down several funding offers and in the end we went with Elephant not for their money but for their expertise in helping start-ups take things to the next level, like expanding into new markets."