How to Build Scalable Modern Web Apps in an All-Remote World
Tags: JavaScript, Software Development, Nodejs, Programming, Scalability

Best Practices for Building Scalable Web Applications

Now that you know what to do, let’s move on to what you do to ensure scalability and consistent performance regardless of the number of users or load.

1. Microservices architecture

Decentralized architecture is a must when building scalable web apps. Modern web development relies heavily on microservices. This type of architecture separates applications into decentralized systems, loosely coupled components, and lightweight protocols. Unlike monolith architecture, this approach allows you to develop, test, maintain, and upgrade individual web services as separate modules without affecting the entire app or the workflow.

The result? Faster time to market, enhanced security, and shorter throughput, load time, and downtime. But more importantly, a decentralized architecture allows you to scale up applications in real-time with minimal disturbance to the end-user.

2. Caching

Caching is scalability’s best friend. If your remote development team is working on any kind of public-facing web service, they should seriously consider implementing some form of caching to avoid having to re-render the page every single time. Caching reduces data-loading costs, allows for faster data retrieval, and eliminates the need to go back to the original database.

That said, caching does come at a price and should be used only where it makes sense to do so. The required time to leave (TTL) of data is what determines the usefulness of a cache. If your data rarely changes, caching it for a long time is generally a good idea. A typical example would be a catalog page that loads the same products with every request and where the workflow stays the same. However, if you need your page to display up-to-date data in real time, don’t cache it.

3. Load testing

You can never know whether your app is scalable or not unless you conduct your load testing pre-deployment. The goal is to create a realistic simulation of the data and user traffic the app is likely to encounter to see how it measures up. It will reveal if there is further work needed for load balancing and also show which areas need improvement.

If you don’t nip potential scalability issues in the bud with a sound load balancing strategy, you will have to deal with them as and when they arise post-deployment. That could lead to costly customizations, reduced performance, downtime, and loss of revenue.

Load testing is particularly helpful when you have a new software engineer joining a project. While the process may affect deployment speed, the slow start is certainly worth it. Thorough system tests, all the way from unit testing to performance testing, ensure that new software developers won’t damage other modules of the app as they start to refactor the code.

If you are utilizing distributed computing, test automation is harder but the risks are lower. It never hurt to be sure before putting web content out on the world wide web.

4. Multiple databases (SQL + NoSQL)

Another shortcut to increasing your apps’ scalability is to use multiple databases, e.g., SQL and NoSQL. While these two are often positioned as opposites for marketing purposes, using them in combination actually helps ensure data integrity, consistency, and reliability.

This approach also increases fault tolerance, lowers the overall costs, and allows you to spread user access across multiple databases — helping with load balancing again. What’s more, you can place the databases in multiple regions worldwide to shorten access times even further. All that has a direct effect on scalability.

The industry has certainly caught up on that. A recent study by ScaleGrid found that 44.3% of businesses used two or even more databases to scale their apps. Out of these, the SQL + NoSQL combo was by far the most popular one and was used by 75.6% of the survey participants.

Whether you combine MySQL, Microsoft SQL Server, or PostgreSQL with MongoDB, MariaDB, or another non-relational database, we have seen many use cases where the combination helped further stabilize the application layer. If you add cloud services and virtual networks and servers into the mix, you are set!

5. Stateless applications

For maximum scalability, consider making your web apps stateless. Under a stateless protocol, the receiving server doesn’t retain user session data. Instead, the data is sent in a way that enables the receiver to read individual packages of information independently of previous packages in the same session. That makes stateless apps ideally suited for high traffic, as this data model lightens the server load and boosts performance.

However, there are some situations in which a stateful protocol works better. These include real-time and stream-based apps with richer data formats where speed and ultra-high performance are essential.