What is SSR with slim?
There's also SSR with react and other js frameworks, but I don't think that's what they meant.
n.b., I've been building Rails apps since 2007. I was a diehard Haml user up until about 2021 when I made an all-in bet on Tailwind and had to switch back to ERB because Haml with Tailwind felt too obtuse.
The only downside is I am now spoiled.
You can of course just drop to `markdown:`.
Still, I use it where I can on personal stuff, but tend to opt for Erb when collaboration with others is needed.