The real cost of ignoring performance budgets

This is one of those topics that looks small until it costs you something. Nobody bills you for neglecting performance budgets. The cost shows up somewhere else.

Performance work is mostly subtraction, which makes it unpopular and effective. Write the reasoning down alongside the decision, because the reasoning is what changes first.

Where the cost lands

• Time spent on work that should not have been necessary
• Enquiries that quietly never arrive
• A number in writing stops slow creep
• Rework, once the problem is finally visible

Budget for total page weight and script size. This is the sort of thing that compounds, quietly, in both directions. The teams that stay on top of it are the ones who put it on a calendar rather than a wish list.

Turning this into a decision

Enforce it automatically or it gets ignored. The teams that handle this well are rarely the ones with the biggest budgets. Check it against what you would want a competitor's site to get wrong.

In practice

Speed is a feature people notice only in its absence, and then they leave rather than complain. Three things worth confirming about performance budgets before you move on:

• Someone can say what the current setup is without going to look
• A number in writing stops slow creep — and you know whether that is true here
• There is a way to tell whether the last change to this helped

None of this needs a rewrite. Most of it is a morning's work once someone decides to do it.