Why Single Page Application (SPA) architecture is so popular?

Single Page Application (SPA) architecture is trending these days due to a simplified and modern user experience. SPA Delivers high-speed applications with reduced “clicks” since data is loaded using multiple calls in parallel. SPA gels very well with the strategy to break any monolithic application into a lightweight application using micro-services architecture resulting in improved time to market. However, with any popular and widely successful approach, there are always people who take it too far. Single-page applications brilliantly fit certain use cases but it is not the replacement for all types of web applications. In order to make a SPA successful, projects need key stakeholders — a user experience team that test new UIs with actual users to validate improved experience by early feedbacks, architects who understand the power of SPA, an experienced development team that can bring an idea into realization and a long-term vision which supports the transformation.

If we take a step back at history to understand how it all evolved - Web Application development is an old (the 1970s) concept that started with digitalization to solve various industry problems using software applications. Earlier we used to have desktop-based applications and then trend started to migrate them as web-based applications using a client-server technology. As technology advanced and more process automation was required, most of the companies continued enhancing existing applications which resulted in “fat” monolithic applications. A big thanks to microservices architecture which initiated critical thought processing to break applications into APIs and easily manageable components. It has also reformed the need to break a Web-Based Application into a Single Page Application enabling the success stories of companies like Facebook, Google, Linkedin, Twitter, Netflix which also helped in promoting the SPA concept in the industry. SPA has revolutionized the basic thinking in the industry to design modern web applications resulting in the invention of modern JavaScript-based frameworks with wide-open support from the community.

Why Single Page Application?

One of the big advantages of SPA technology is that it allows companies to port fat on-premise / cloud applications to lightweight native applications without making big changes to the UI or established workflow. A smooth and familiar desktop-like user experience is undoubtedly the biggest strength of a SPA. Additionally, it is easy to port applications into the cloud. Below are few strong reasons to adapt SPA:-

· Path forward to modernize monolithic complex applications — SPAs are being considered as an approach to break the monolithic applications into SPA to meet business needs. Most of the business areas are trying to develop SPA for specific segments of users and related workflows.

· Simplified and Modern User experience — SPA provides rich UI content with simple and modern user experience and it is easy to port across platforms

· Minimal User Training required — Typically, organizations make huge investments in training new associates which include environment setup and infrastructure costs, etc. Per the research, SPA needs no or minimal training as screens are designed based on extensive UX research and surveys.

· Simplified deployments and rollback with high-speed delivery — SPA provide lightweight applications, which are easy to package and deploy applications to production. Compare to monolithic applications, time to market is improved with SPA.

· Reduced clicks — SPA renders all important information in a single view by making multiple calls in parallel and most of the actions can be taken with fewer clicks compared to a fat web application.

· Easy Debugging using browsers — SPA makes it easy to debug application code using network tab and inspect options.

· No need to wait for the whole app to be loaded — Application data loaded in parallel using asynchronous manner, so the user doesn’t need to wait for the application to be fully loaded as data would be shown on the first response.

· Easier state tracking — no need to use cookies, form submission, local storage, session storage, etc. — typically in any multipage application, there are always challenges in terms of sharing data across pages and if we utilize solutions like HTTP session then session management is also a big challenge. Such challenges are not experienced in SPA applications.

· Boilerplate content that is on every page (header, footer, logo, copyright banner, etc.) only loads once per typical browser session — This is one of the key differentiators for SPA based application since the application is loaded only once per browser session so boilerplate code is always available and it saves time for the rendering of applications.

· Responsiveness — Easy to implement the responsive application with SPA specifically to maintain only one screen and it can easily be utilized on mobile devices.

· DevOps and Automation — Continuous Integration /Continuous Delivery and automation is easy with SPA-based applications compared to multipage or monolithic applications, resulting in a faster pace of delivery.

Approach for SPA — Design and Development Considerations

As a standard practice, before kicking off any development effort, the team needs to research and consider tools, technologies, architecture, methodologies, and platforms. Few consideration below:

Technology Considerations — If a team has decided that building a SPA best suits the project requirements, then building it on a powerful framework is mandatory. It also depends if you are using OSS, COTS, or SAS products.

Below are a few top-rated SPA frameworks but in my view, Angular leading the race due to the following reason:

· Community support — As of today more than 50 % of the developer community is using Angular for SPA and actively contributing to expansion and improvements for Angular

· MVC architecture — If there is a need to break a monolithic application into a lighter application and if we need to perform a lot of data manipulation and API calls and then Angular is well suited for such needs

· Training — It’s easy to upskill our existing team with Angular and it is easy to find and hire Angular developers from the market compared to other client-side frameworks.

Architecture Considerations — For designing a SPA application following are key considerations :

· Design for Future by leveraging 12 factors Cloud-Native Application Architecture principles

· API First Approach to keep application modular and extensible with future interactions

· Flexible & Extensible UI implementation for an Improved Customer Experience.

· Enable rapid development enriched by DevSecOps to Increase Speed to Market

· Design UI to meet WCAG 2.0 standards so that contents are perceivable, operable, and understandable.

· Responsive design compatible with major browsers

Platform Considerations — This is quite an important one as the solution has to support the overarching goals of any organization. So, the selection of the right platform OSS, COTS, or SAS should meet the long-term vision.

Conclusion

The benefits of using Single Page Applications are multifold. While there are new trends in the web applications arena with improvements in SPAs such as Progressive Web Apps (PWAs), SPAs are definitely a step in the right direction towards web application development for the future. SPAs have a couple of disadvantages despite having numerous advantages. Some of the issues with SPAs are — it does not perform well with Search Engine Optimization, consumes a lot of browser resources and multiple parallel calls may cause performances issues. However, there are various ways to handle these challenges, with SPAs advantages outweighing the disadvantages. Additionally, the combination of SPA, microservice architecture, and DevSecOps makes it a unique solution and has the potential to solve many of the industry problems. Micro frontend architecture is also complementing SPA in terms of service-support and decoupling aspects.

Overall, it helps to provide an improved user experience, reduction in maintenance cost, and improved time to market.