The application slowed down when the data has grown, the reports system failed beyond a certain volume of concurrent users, the new feature cannot be introduced without design level change or a simple bug fix needs hard coding rather than a well-developed fix.
Every developer comes across these scenarios someday in their career and that’s when the scalability aspect of the software stands out. In general, scalability is related to data volumes or user volumes – but that’s just a part of the whole scalability story. To have robust and sustainable applications – scalability is a critical aspect to give attention to right from the conceptualization stage of the application. Right design decisions pay off in long run to achieve the desired scalability easily and save loads of costs incurred to modify the application to desired performance.
When we talk about scalability, we not only have to keep performance in mind but also maintainability and extensibility. An application that is difficult to maintain/extend is bound to see its demise in a very short period. After all sizeable revenue in the software industry is generated from maintenance and enhancements. So following design principles during development proves to be crucial in making the application code easy to understand, maintain and enhance.
Today’s world is about handshaking with external entities, almost all applications are expected to extend their data, functional flow to the systems outside the scope of the application. Ensuring the application is ready to extend is also a critical aspect of ensuring scalability.
All in all – Scalability is one of the key NFRs of any application. With appropriate attention to various aspects for the same right from conceptualizing the application would help them get a highly scalable application. Chances of the application running for decades and caters to almost all performance, maintenance, extensibility needs will go higher.
What are the best practices you follow when designing scalable software?