Web performance: prevent wasteful hidden image requests (display: none)
We often hide images using CSS with "display: none", but this doesn't actually prevent the browser from downloading these images. Using the HTML Picture element, we can serve different versions of an image depending on media queries. We can even use a data-img to prevent images from being downloaded at all and optimize our website speed.
Crawling through Umbraco with Robots
The robots.txt file’s main purpose is to tell robots (Google Bot, Bing Bot, etc.) what to index for their search engine, and also what not to. Usually you want most of your website crawled by Google, such as blog posts, product pages, etc., but most websites will have some pages/sections that shouldn’t be indexed or listed in search engines.
Ignoring Umbraco ping.aspx from Azure Application Insights
Application Performance Monitors provide you with a lot of data, but some of that data may not be relevant. Specifically, in Umbraco there is a page at \umbraco\ping.aspx that is being called frequently to keep the site alive. This is very useful to prevent the site from "dying" (?), but the data for this request isn't that relevant and could skew your statistics. Using Azure Application Insights ITelemetryProcessor, we can prevent ping request from being sent to Azure Application Insights.