Before we start any optimization, we should have metrics, then we can start to optimize, this way we have clear goal to achieve and to compare with the past.
![Video preview](https://i.ytimg.com/vi/kMQxQz0WwDk/hqdefault.jpg)
![It’s from the video, before you start it’s important to know what stack we’re talking about](/_next/image?url=https%3A%2F%2Fwww.notion.so%2Fimage%2Fhttps%253A%252F%252Fs3-us-west-2.amazonaws.com%252Fsecure.notion-static.com%252Fd39d5e99-dc73-449e-ba2a-870ae11dbe56%252FScreenshot_1.png%3Ftable%3Dblock%26id%3D7c85d7fc-a6e3-4c3c-9ba1-c05687797b8c%26cache%3Dv2&w=3840&q=75)
Chrome Developers 2017 (outdated)
![Video preview](https://i.ytimg.com/vi/zFoBYfMLUCM/hqdefault.jpg)
You can read on the title of this section, the ‘outdated’ word, because of this I removed every notes I did and will keep here only the summary of the information from the video you can use in the future:
![notion image](/_next/image?url=https%3A%2F%2Fwww.notion.so%2Fimage%2Fhttps%253A%252F%252Fpaper-attachments.dropbox.com%252Fs_92EF0F11F95E9C4A6DF79CE9AA886D2044F207550561730B6CBD42BB9A2DE0E3_1583025023965_Screenshot%252Bfrom%252B2020-02-29%252B22-10-07.png%3Ftable%3Dblock%26id%3Da98b1bc2-fb9d-49b2-98bc-3e68571e796c%26cache%3Dv2&w=3840&q=75)