1. Sign up to Firefox sync
2. Install the Multi-Account Containers extension. Create containers to partition your identities. Eg: Banking, Shopping different Gmail accounts, different AWS console accounts etc
3. Install the "containerise" extension so you can create URL rules that automatically open sites in the correct container. (It can match URL regexes, allowing you to identify different accounts on each platform. Eg: on gmail, 'mail.google.com/mail/u/?authuser=hunter12@gmail.com', which you can bookmark as "Hunter12 Gmail")
4. Kagi search
5. uBlock Origin extension
6. Simple Tab Groups extension