AWS Case Study: Interviewing the World with Active Interview

Active Interview is fully deployed through Amazon Web Services (AWS). The Active Interview Web application is written using the Ruby on Rails framework, with the primary Nginx/Passenger/Rails Web servers running on Linux-flavored Amazon Elastic Compute Cloud (Amazon EC2) instances.

“Deploying a Rails app to [Amazon] EC2 couldn’t be easier,” says Active Interview co-founder Sandeep Ghael. Active Interview originally looked at other cloud vendors but chose Amazon for its credibility—particularly the AWS libraries for Ruby, Python, and Java developers. “The Rails community support for AWS is fantastic, and the solutions are really well vetted and understood by the developer community,” says Ghael.

Most of the front end of the Active Interview application is handled with a handful of small server instances, while video interviews are stored in Amazon Simple Storage Service (Amazon S3). The Active Interview team expects to scale horizontally with Amazon Elastic Load Balancing.

“One of the truly underrated features of AWS is the ability to directly serve content from [Amazon] S3,” says Ghael. The team never worries about heavy video viewing saturating Web server bandwidth, as their Web servers stay solid and responsive no matter how much video media is streaming. “Amazon S3 should be called ‘secret sauce storage,’” says Ghael.

Active Interview uses video manipulation tools FFmpeg and ImageMagick to post-process and create video thumbnails. Active Interview started with a self-managed Red5 installation on Amazon EC2 but moved to the Wowza media service when they realized that AWS offers a metered (pay-as-you-go) option for that software.

Active Interview uses one dedicated Amazon EC2 instance as a continuous integration service. “On every code check-in, the entire test suite is kicked off, and we know immediately when there is a build issue,” says Ghael. “[Amazon] EC2 makes it cheap and easy to test our app in a totally equivalent sandbox.”

The Active Interview prototyping phase took two months, and the team was able to test storage architectures without having to buy network-attached storage, binding themselves to a 12-month server contract or up-front expenses. Ghael was also impressed with AWS’s preconfigured Amazon Machine Images (AMIs). “Not having to build those AMIs from scratch and knowing they were built by the vendor [Wowza] was a major bonus. I’d say we saved around three man-months on our initial beta app deployment using AWS,” says Ghael.

Ghael cites his competitors in the online interviewing space and the “order of magnitude differences in our operational costs,” not to mention “huge capital outlays” that those competitors made on infrastructure.

Ghael recommends that other Internet businesses map out the cost of a typical managed hosting solution. After analysis of their costs, the Active Interview team began backups on data and server instances through Amazon Elastic Block Storage (Amazon EBS) and Amazon S3, making the switch from managed hosting fairly trivial and the cost savings significant.

Active Interview is committed to AWS for the foreseeable future.

“We’re in the golden age of Internet businesses. Open source frameworks, higher-level languages, API services, and metered cloud services are all the tools you need to take you from ‘good idea’ to sellable product. The tools to create a software-as-a-service business are here, and it’s the smart businesses that are using it as a competitive advantage,” says Ghael.

To learn more, visit http://www.activeinterview.com .