When we talk about scalability, we mean a system’s ability to cope with an increase in workload, whether in terms of users, processes or data, without compromising on performance or efficiency.
In the context of computing and technology, It is a fundamental property for ensuring that a system can grow and adapt without any problems when implementing new features, as well as when dealing with a higher user load.
Scalability is a rather flashy term that is sometimes used haphazardly, without us realising the complexity involved in designing and programming scalable systems. Thus, software is scalable when it can grow in complexity and size without failing or crashing.
Types of scalability
There are two main types of scalability: vertical and horizontal.
Vertical scalability
This involves to improve a system’s performance by adding resources to a component that has already been created. To achieve this, technical improvements need to be implemented, such as increasing the computer’s processing capacity and storage memory.
Imagine you have a web server that is under heavy load. To ensure the system can handle these changes and new features without crashing, you could improve its performance by adding more RAM or by upgrading the computer’s processor capacity. This is commonly known as ‘scaling up’.
Horizontal scalability
Horizontal scalability involves add more instances or nodes to the system to distribute the load amongst them. Rather than strengthening a single component, additional identical or similar components are added in order to achieve a overall improvement of the system.
If you have a web application and experience a surge in traffic, rather than upgrading the specifications of a single server, you can scale horizontally by adding more servers to your infrastructure. A load balancer will distribute requests across these additional servers. This is commonly known as scaling out.
Why is scalability important for a business?
Scalability brings significant benefits to a business by providing flexibility and adaptability for your bespoke software systems as they grow and needs to incorporate new features and user flows. When a company takes its structural scalability into account, it develops the capacity to manage its growth efficiently in terms of user volume, diversification of work processes and data storage.
A company that can adapt to growing demand and new procedures can optimise its investments by cut back on unnecessary expenditure and improve the return on investment. Furthermore, a scalable organisation always has its sights set on the future, as it seeks to adapt its systems with a view to potential improvement or growth. Consequently, scalable companies can expand their operations without having to radical changes in its technological architecture.


