The real problem
Three seconds. That is all it takes for your e-commerce customer to abandon the purchase while the page is still loading. Performance is not technical vanity: it is revenue that either arrives or does not, measured in first paint and time to first interaction.
On the operations side the problem is different, and worse: without instrumentation you do not know what is breaking, nor what it costs. It is like steering an ocean liner with no instruments and hoping to arrive in one piece.
We instrument both sides. The technical one (infrastructure, application, database, queue, integration) and the business one, with sensors showing orders per minute, conversion and revenue in real time. When either moves in the wrong direction, somebody knows before the customer does.