Yeah, as a SWE I just got sufficient money to pay my expenses AND have some to invest quite recently (about 2/1 months ago), but I basically froze the money instead of investing because everything seems overvalued and about to fall (even silver and gold).
I would argue that parts of the economy should (hopefully) remain healthy. I mean, AI bubble or not, people need medicine, food, internet access, energy, ... . Invest in that.
Also (not a financial advisor), when a crash occur there is a so called "flight for quality" where people move money they made by cashing out the assets to stable (A+ assets). So look for companies that have solid financials and can weather the storm.
Finally, diversify not only on the industry, but also geographically. EU, Swiss, Asian. I personally stay a bit away from emerging markets stuff as I don't have enough knowledge to make informed decisions (I don't even consider Emerging Market ETFs which should be run by SMEs).
Be careful, I would not stay 100% invested or 100% uninvested. The market can remain in an Everything bubble for far longer than we expect (see: since 2008). It can be a lot harder psychologically to get back -into- the market when you're totally out because of sunk cost fallacy (thinking, I gotta wait just a little longer and this thing will finally crash).