Do you put on concealer or eyeliner first?

Excuse me, but I couldn't help but overhear your question about makeup application. I'm curious, what's your thought process behind asking whether to put on concealer or eyeliner first? Personally, I've always found it helpful to start with concealer to cover up any imperfections or discoloration, before moving on to add definition with eyeliner. But I'm always open to hearing different perspectives and techniques. What's your take on this?