I recently went through the job search process, aiming to land a job at a remote first company. Here is a list of sites I found useful, and at the end one site that you should definitely not use.
Best site of them all
Remote Leaf is a paid email subscription that curates remote jobs - easily, the best option if you are looking for remote jobs and don't want to have to trawl the internet
Best job boards
Sites to add your profile too
Beyond the goliaths LinkedIn and Stackoverflow, it is worth having a profile on these sites:
Got my job from here, although admittedly it was the only useful lead I got.
The below 3 are not remote specific but useful if you are from the US or UK
Hired (Only useful for US or UK citizens)
Vettery (Only useful for US citizens)
Triplebyte (Again best for US citizens)
Here is dump of other useful sites:
(Disclaimer: I have not used all of these so can't vouch for how good they are)
Lastly, do not use remoteleads.io - they scammed me
You can see the full details here but in short, I and a few others paid for their premium service and never heard back. After being very friendly, the founder disappeared, didn't reply to my messages through every possible avenue, blocked me on Twitter and I ended up having to claim the money back through my bank.
Good luck on the job search