Client-serverless is the 4th generation application model
We are just beginning to enter a new world of ubiquitously accessible client-serverless applications. Just like the client-server and three tier architectures did, the client-serverless application model will create tremendous opportunity (and disruption) for every kind of customer and vendor in the industry.
Application models do not change very often, but when they do, they create many opportunities.
I had a front row seat at Microsoft to watch the first two application model transitions. Early mainframe and minicomputer systems were monolithic, with data storage, application code, and terminal services all in one box. When the microprocessor and ethernet networks emerged during the 1980s, they enabled lower-cost computers to work together and communicate over local area networks. PC’s and Unix workstations began to connect to servers, leveraging a new, multi-machine, client-server programming model for business applications. Client-server applications emerged with a graphical user interface coupled to a backend SQL Database (frequently Oracle or SQL Server).
Client-server applications were built very differently than monolithic applications, with the presentation code running on the client computer and business logic on the server, typically encapsulated within SQL stored procedures:
I watched the client-server journey begin over 30 years ago, while working on my first Microsoft product, the Ashton Tate/Microsoft OS/2 SQL Server.
Client-server applications flourished for only a brief period but they created a new generation of easy-to-use, graphical applications that delivered computing to hundreds of thousands of small businesses for the first time. The combination of Visual Basic client applications calling SQL Server stored procedures built the Microsoft server business and created an entire industry of software vendors and value-added resellers. While client-server has been a legacy approach for over 20 years, many businesses continue to run updated versions of these same client-server applications.
Client-server became legacy because of the Internet and the Web. Client-server applications were built for local area networks using chatty, proprietary protocols that worked in a local-area network but were inappropriate for the long distances required by the Internet.
The Internet & Three-Tier Applications
In the spring of 1995, Bill Gates redirected Microsoft’s focus to the Internet with his famous Internet Tidal Wave memo. At the time, I was running Windows NT Program Management so I attended many “Billg Internet Planning” meetings. This was the beginning of a tumultuous period for Microsoft and I watched and participated in everything – the good, the bad, and the ugly. Together with Microsoft, I learned many lessons from the Internet experience and the antitrust episode that followed. One of the important lessons is how technical revolution creates new win-win opportunities for everyone.
The revolution of the global Internet brought a new generation of open standard protocols and formats. These new technologies required different infrastructure. Initially, simple web servers delivered static websites. But commerce and other applications quickly drove the emergence of a new, three-tier application model:
Unlike client-server, the three-tier application model has aged quite gracefully and is now used to provide API services in addition to web pages. The evolution of a standard API interface based on REST has enabled complex business logic to be encapsulated within globally available services that are callable by any application with the appropriate security credentials. The three-tier application model is commonly used to provide REST API services:
The browser in the sea of serverless APIs
When services are delivered as an API, are automatically scaled within a cloud, and are priced based on usage, they are known as serverless services. With severless, customers don’t need to manage the server infrastructure. Serverless services are available to any appropriately authenticated device, anywhere, and they are billed based on a relevant usage metric.
Today, we find ourselves in a connected world with a variety of powerful mobile and portable computing devices. All of these devices now support compatible browsers that are capable of providing an end user experience that approaches or in some ways, exceeds the quality of a native application on that device. An example of this is Google docs, which uses the browser to provide a seamless, collaborative experience across devices.
At the same time, new SaaS applications are being reimagined as a complete set of Internet-compatible APIs that deliver an ever-expanding variety of different services using usage-based pricing. Payment, content management, logistics, order management, 3D printing, you name it, they are all becoming APIs that are callable from anywhere: other servers, mobile applications and the browser. The cloud accelerates this adoption by enabling serverless computing and new tech companies like Stripe, Twilio, and Algolia have emerged as leaders in this new class of usage-based services.
After a long evolution, the browser has become a ubiquitous, programmable client that lives in a globally connected world of serverless APIs. This combination of a ubiquitous client together with a sea of serverless APIs has enabled the new, client-serverless application model:
In client-serverless, the end-user application runs on the client and calls a wide variety of services. The client handles the presentation while the business logic is encapsulated within callable services. Native IOS and Android applications are examples of client-serverless but the browser is where the action is and Jamstack is growing rapidly. As client-serverless matures, it will grow to support consumer and business applications of any size or complexity.
Client-serverless also applies to servers and microservices that are orchestrating business processes. In this case, the server application or workflow engine acts as the client making calls to remote services using serverless APIs.
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Jamstack & the client-serverless database
The Jamstack approach enables very powerful client applications to be developed. Like all applications, Jamstack client-serverless apps create data that needs safe, secure, transactionally consistent database storage. But unlike three-tier, Jamstack applications require a secure database that is available anywhere on the Internet. Existing SQL and NoSQL databases are all built to sit behind an app server so they are not directly accessible to Jamstack client applications. No existing database meets the requirements needed by the new generation of client-serverless applications.
Jamstack requires a database that was built for the client-serverless world. In a sea of serverless APIs, what Jamstack needs is a serverless data API.
Serverless APIs are redefining what is possible in today’s world. These possibilities are accessible to businesses modernizing their current systems as well as those building completely new client-serverless applications. For example, Fauna customers like Nextdoor and Hannon Hill are using serverless backends to scale their existing infrastructure for global reach. Boutique studios such as Matter Supply, Bejamas as well as startups such as Faros are building entirely new experiences with the serverless, Jamstack, and Fauna ecosystem.
Every revolution in application architecture has spawned a new database that enabled developers to build applications that were not possible before. I am excited to help the Fauna team deliver the database that was built for the client-serverless world. Fauna is the data API for client-serverless applications.
We are just beginning to enter a new world of ubiquitously accessible client-serverless applications. Just like the client-server and three tier architectures did, the client-serverless application model will create tremendous opportunity (and disruption) for every kind of customer and vendor in the industry. A new generation of developers are leading the way with Jamstack.