Importance of Scalability in Application Development

Author: James
March 25, 2019
Importance of Scalability in Application Development

Defining the term scalability within the realm of application development

Application development, be it for the mobile or the web or any platform for that matter, is not a straightforward process. It involves taking into consideration several factors before drawing the big picture. One of those serious considerations lies within the term scalability. You can check out our blog on scaling MVP applications here. From a fundamental standpoint, scalability refers to the inherent capability of an application to handle and sustain a growing number of customers, clients, users as well as the addition of newer features. It refers to a perceptive approach to app development, wherein you factor in the app developer’s ability to maintain the app and sustain it for an extended duration of time. If the app you have built doesn’t tick the scalability box, adding new features at a later point in time or expanding the app’s capabilities may cause quite a bit of a challenge. This renders the app remaining dysfunctional beyond a specified period.

Scalable application development

What does scalable application development entail?

Meticulous planning is an integral part of scalable application development. Performance centricity is therefore crucial for an application to sustain the test of time. The elements of design and functionality are the essence of scalability. Both performance and sustainability govern them in design and development principles.


Performance is usually characterized by aspects of speed and effectiveness of an application under a given workload within a given time frame. They take it into consideration elements such as speed, throughput, responsiveness, and availability. Speed is usually measured by the amount of time it takes to transmit data, while throughput is more quantitative in that it takes into account the number of transactions carried out per second. Responsiveness, as the name indicates, measures the amount of time taken to respond to a particular request by the end- user. In effect, scalable development is not a unique process in itself. Instead, it refers to the adoption of a set of principles and techniques that help you design an application that maintains a high standard.


The software is meant to last long and be sustainable over a significant period. We invest in resources for writing code and developing an app. Therefore, maintenance is the key to development. Update parts when needed so as to ensure that it operates properly. We can use various platforms and tools to help us monitor our application. Of course, we want to do as much as possible of this automatically.

Expenditure and costs:

Application development incurs several costs that include development, maintenance, and operational expenses. When we design a system, we need to bring about a balance by making use of existing components and developing everything ourselves. Existing components may sometimes not fit our requirements, but outreaching for additional development costs should always be factored in during application development.

Let us explore different types of scaling before we get to further fundamentals.

Vertical scaling:

It is possible to achieve scaling in two ways – “scaling up” or “scaling out” Vertical scaling or scaling up, as the name indicates, is employing of better quality and high-end resources to carry out a process within an application. For example, running an application on a machine with a faster CPU would be vertical scaling. This, in turn, would boost performance and therefore scale the application vertically.

Vertical scaling comes with its advantages and disadvantages. It is simple to execute considering that the same application can be run across machines of varying capacity without extensive changes to the app. In terms of the cons, vertical scaling is not suitable to be applied infinitely since there’s a limit to hardware advancement within a stipulated time frame. The fact that it also gets more expensive as it scales into pricier equipment is a significant cost-incurring expenditure.

Horizontal scaling:

Typically, horizontal scaling or scaling out involves ramping up more resources to run an application by adding more nodes within it. Running an application on multiple machines as opposed to one device is how horizontal scaling is set apart from vertical scaling. Horizontal scaling comes at a much lower cost considering that the additional resources are similar to each other in type and deployment. Also, it is much easier to carry it out without significant downtime. However, without the proper application architecture and framework, though, scaling out can lead to a drop in performance as the nodes struggle to communicate with each other.

Data migration:

When factoring in the aspect of scalability, moving existing data to newer and larger scalable systems becomes a crucial consideration. In the age and time where 24*7 functionality is expected for the app to be up and running, moving the database to another server can be a problem for the working application. For database migration, it would be ideal to follow these steps:

Plan ahead: 

Placing an announcement about downtime much ahead will allow sufficient time for data backup and other preparatory steps not to lose the productivity of an app. When audience activity is minimal, this step is suggested.

Use replication:

Replicating data to synchronize data from one server to another is one of the most useful steps during data migration. After configuration, one is advised to change the database IP address in the application to the new server. Following this, the old server can be turned off. This completes a successful migration.

Benefits of using a scalable application:

Using a scalable application is indeed beneficial. It provides increased agility, ample flexibility, and more sustainability. All businesses, regardless of size and capacity, should consider developing a scaling strategy. If they fail to do so, they are being short-sighted and can see themselves falling short in the long run. It is quite apparent why established enterprises should offer flexibility in their infrastructure to add new products or services. However, SMEs need to be agile as well as we live in the age of digital.