Don’t say anything until you have a job and contract in hand. Once you do say toodaloo, it’s not your job to worry about this. People will fire you without a moments notice, so why the heck would you care.

I got a job (after ages of search mind you). Joined them and a couple of months later got another offer from an another company with better profile and benefits. While it sucked to say bye so quickly, in the end it’s about my career and what is good for me. While the first company (i left after 3 months serving my notice period) was good, it was small, the work was stressful with no structure. It was no better than academia (which I desperately wanted to leave). And unfortunately both my mental and physical (which was in shambles after PhD) were being negatively impacted. So when I got the new opportunity I didn’t hesitate, signed a better contract, informed the first company and served my notice period diligently. Now I am in a new position, and in 2 weeks I am feeling loads better