I have a plan about measuring our platform(SPA)'s performance and tracking a metric result everyday.
There are two metric that I can measure.
- domcontentloaded
- load
Which one is more effective for SPA platform?
// notes (I already knew there are many metric(FP, LCP, ....) but in this time, I just want to take only one metric in domcontentloaded or load.)
TL;DR: choose a modern metric. DCL and load are ineffective measurements for page load performance.
Both DOM Content Loaded and the plain load event are generally seen an outmoded, poor signals for page load performance. There are some technical differences between the two (DCL happens as the browser is finishing up parsing the DOM (basically the last step), and load happens once that parsing is complete).
Using a more modern standard will provide much better signal WRT how your page is loading. You mention Largest Contentful Paint, which is possibly a good one to choose, given that LCP tends to correlate with when people see a site as being "ready." Total Blocking Time may also be helpful for a SPA, as that measures the amount of time between FCP and TTI where the site was unable to handle user input.