This article was originally published by Dan Woods on Forbes on February 11, 2015

In the tech community, Netflix is a company that everyone learns from. But what is less widely celebrated are the broader business lessons of what Netflix has accomplished. I was bonked over the head by this point when I sat through a presentation about Experience-based APIs by Daniel Jacobson, VP of Edge Engineering for Netflix.

Jacobson and his team that builds and maintains the Netflix API platform have developed a way of working that solves a problem that is common in any company that is building its own technology: How do you best leverage the skills of everyone on a team so you can move as fast as possible? Jacobson and his team have figured this out for a general use case: Building many different applications based on a complex set of centralized resources. The structure of this solution, which relies on the idea of separation of concerns between different groups of developers, can help optimize the structure of many different types of teams.

For those who work on building software, Jacobson has embedded in the Nicobar open source project the technical capabilities needed to support for the separation of concerns and rapid innovation. I will describe briefly the Nicobar project, which was released yesterday, at the end of this article.

What are Experience-based APIs?

To understand the beauty of Experience-based APIs, we first must understand the challenge facing Netflix with respect to supporting many devices. Netflix client developers write software applications that allow Netflix to deliver its content over thousands of different devices types. Netflix has many teams of client developers, each of which specialize in creating applications for different types of devices. The goal of Jacobson’s team and the client development teams is to deliver a great user experience and make sure that Netflix works perfectly on any device you might use, from an iPad, to an Android phone, to a DVD player or smart TV.

In the Resource-based API platform the work gets done this way:

• The central API team creates APIs that make it easy to get to all of the data and resources of a company. These APIs are all about creating a general way for programs to get access to customer data, data about films, recommendations, and so on. The resources that a client program may need include data and services for:
  • User info
  • Movie metadata
  • Movie Ratings
  • Similar movies
  • My list
• The central team implements the APIs to deliver scalability and excellent performance.
• The client team takes these APIs and creates applications for a variety of devices. The problem is that the code for handing errors and adapting the data to the needs of the device all resides in the client application code.

The Resource-based API paradigm works just fine and is used all over the world. But Jacobson and his team wanted to find a way to move faster, create better software, and enable more optimized experiences for Netflix subscribers. They realized that different devices potentially needed a different set of data to support the user experience. The best way to make the client software simpler would be to have a new API that allowed as much as possible of the data translation, error handing, and other utility functions to happen on the server, not on the client.

But if you asked the central API team to create versions of APIs for all the different families of devices, the team would be overwhelmed. In addition, it would be hard for each of the client teams to actually ask for the right design for the APIs they would need. It would require trial and error and that would be hard to accomplish with many client teams competing for the attention of the central team.

Jacobson and his team realized they needed to create a new layer of API they called an Experience-based API. The idea is that the client team should design the perfect API to serve the needs of the device on which the client application will run.

For example, when writing the application code to create a page on the client using the resource-based approach, the developer may have to call a dozen APIs, handle errors from all of them, and then format the data for use on the page. All of this communication takes place over HTTP, which is less efficient than the networking methods used on the server.

But if the client developers could create their own API to support the needs of that page, and move all of the code for data access from the client to the server, lots of good things would happen such as:

• Client code would get simpler.
• More code could be shared across families of devices.
• New device families could be supported faster in a way that best fit the needs of the device.
• Performance could improve because network communication is optimized, reducing round trips from the device to the server.

So Jacobson and his team set out to create a new layer to enable client developers to create their own APIs. Here’s how it works:

• Client developers analyze the application that they want to build for a particular client and then decide on the APIs that they will need to support them.
• They define the endpoints of the APIs and protocols to handle the requests and responses that are optimized for their client
• The APIs are implemented by the client developers using the Groovy scripting language which is used to call Java APIs that will gather the data needed to handle the request. Groovy is easier for client developers to work with than Java but still is scalable enough.

This architecture, in the case of Netflix powered by Nicobar, allows the client teams to move faster and reduce the technical debt by making the client programs simpler. The code enabled by Nicobar is more shareable and easier to maintain.

“There are some significant engineering benefits to this structure, but the real win is increasing the velocity of innovation,” said Jacobson. “Because Experience-based APIs properly separate concerns across the two teams, the work gets done faster. The client teams control their own velocity and the server teams can focus on building the platform that supports them.”

Lessons for the Rest of Us

Jacobson, Greg Brail, Chief Architect of Apigee, and I were co-authors of “APIs: A Strategy Guide”. During the time we wrote the book in 2010, the world was focused on the impact that public APIs were having. Google, Facebook, Twitter, and Amazon all harnessed massive amounts of attention and energy as people put their public APIs to work.

At that time Jacobson argued that internal use of APIs would have the far larger impact. He saw that few companies, even Netflix, would be able to get a large amount of value from public innovation. Instead, the real victory would come as internal APIs increased efficiency, productivity, and the velocity of innovation. Experience-based APIs are one major proof point for Jacobson’s way of thinking.

I believe this two-tier structure that allows those closest to the problem to translate the Resource-based APIs to a more suitable form and create APIs that are adapted to their needs can be used in all sorts of companies who how have bottlenecks in their IT departments.

To make this work you need a front office IT staff, one that works with the business. These are the equivalent of the client teams at Netflix. The back office IT provides Resource-based APIs to the front office teams who then use simple tools, scripting languages, model driven development, content management systems, and so on to adapt the resources to the needs of the business. In large Wall Street Firms it is common to have highly skilled front office IT teams. I think that many companies could benefit from this model if they choose the right tools and create the right separation of concerns.

Nicobar 

For companies who create -multiple applications and are committed to the Java ecosystem, Nicobar is definitely worth a look. This library provides the core functionality to implement the Experience-based API program. Right now the Groovy language is the way that the adapter code to assemble the data needed for the Experience-based is written, but in the future other JVM languages may be supported.

The key capabilities of Nicobar are:

• Rapid application delivery via dynamic updates of components
• Ability to add support for multiple JVM languages

To learn more go to Nicobar: Dynamic Scripting Library for Java.

And, for the truly nerdy, here’s what the project wiki says about why the project was called Nicobar:

“Nicobar refers to a remote, archipelagic island chain in the Eastern Indian Ocean. It is aUNESCO World Biosphere Reserve, and like many other remote volcanic islands, it has rich biodiversity, and various endemic species are found here. Taken together with the surrounding Andaman group of islands, six different human tribes occupy these islands, each with its own spoken language. We felt that these isolated islands, evolving independently are a good metaphor for the polyglot, modular runtime framework we were setting out to build.”

Dan Woods is on a mission to help people find the technology they need to succeed. Users of technology should visit CITO Research, a publication where early adopters find technology that matters. Vendors should visit Evolved Media for advice about how to find the right buyers. See list of Dan’s clients on this page.