https://blog.amplitude.com/getting-your-product-team-to-a-growth-mindset-requires-kdis-not-kpis

Key diagnostic indicators measure the true performance of your product. Here’s how to make the switch.
Have you ever worked really hard in delivering the best feature you possibly could and, right after launch, your key performance indicators (KPIs) go down?
Imagine thinking afterward that you did everything in your power to make sure the feature worked: you followed all the best practices and got user feedback. So how could your work show a negative trend on your performance indicators—the indicators your performance is linked to?
With KPIs, this story is personal. The story your data is telling you has a direct impact on your ego. Your work = the performance of the product. This is the problem with the key performance indicators.
As a growth leader, you know the performance of a product looks more like this:
Than it looks like this:
Naming your data “key performance indicators” puts a lot of pressure on the team to meet performance levels that prove they are good at what they do. But It’s stories like these that create the world of vanity metrics.
When you are optimizing the product around vanity metrics that you can hack to make go up, you are sacrificing the true growth of your company so that your employees can feel good about their effort.
The true measure of success is if your team is learning, not if they are meeting a specific level of a vanity metric. In order to help switch your team’s mentality to growth and ensure they are learning, change your KPIs to KDIs using the guidelines below.
Common vanity metrics include: