Timeline for leaving postdoc I plan on leaving my current postdoc at the end of the first year to go to industry. My question is two fold: 

Is 3 months a good length of notice to give? 

When should I begin applying for positions in industry?

With regards to the first, there are already plenty of answers saying the more the notice the better, however I do not want to give too much in case I am replaced before the end of the year.
I would ideally like to begin a post in industry (computer science) at the beginning of 2020. It may be too early to begin applying now but I'm not sure about the interview timeline etc.

Thanks in advance.
You should always be applying.  Postdocs are short term positions.  It is understood.
Give notice after you get AND have accepted a firm written job offer.


You really don't owe any more than that.