Scalability

Scalability is what decides whether your system still feels fast when the number of people using it grows. Five staff log in at nine in the morning and everything opens instantly, but add a hundred and the same screen takes twenty seconds. Nothing has broken, the work simply got bigger than the machine underneath it.

The causes are usually dull and specific, and the most common one is a report that reads the live data while everyone else is trying to use it. A manager opens last month's sales at eight, the database locks up while it counts, and every cashier in every branch waits. Images do it too, because a photo straight from a phone can be six megabytes. Put forty of them on one page and the page is a quarter of a gigabyte before a single word appears. The third cause is the server itself, often one small shared box that was fine for the first year.

None of this is a mystery to solve afterwards, because it is a set of choices made at the beginning. Copy the heavy reports onto a second copy of the data, so a manager's curiosity cannot slow down the counter. Resize photos once on the way in instead of every time they go out. Then put a number on how many people will use the system in year three rather than year one, and size the hosting to that.

Fixing it later costs far more than allowing for it at the start, and the reason is not the hosting bill. It is that the shape of the data has to change, so every screen that touched it has to be rewritten and tested again. Work that would have taken two days in the first month can take six weeks in the second year. That is why Linkysoft asks for the year-three number before writing any code for a web application project, because that single answer changes the design.

So ask a supplier one question before you sign, which is how many people the system can handle at once and what the next step up costs. A clear answer means someone has thought about it, and our own Hostrena hosting exists partly so that answer is a number rather than a shrug. Linkysoft would rather give you that number early.