What's it like for foreigners? Does one have to seek out the ex-pat crowd or does everyone mix?

Probably not what u wanted to hear, but: When i was there: 30°C at day, 28°C at night, 100% humidy. Not really a place i want to live.

I was in Singapore in April and I liked the weather. The people I worked for did tell me that in the summer the weather was not so good.

The startup scene tends to be more foreigner friendly. For corporates/enterprises it's a mixed bag because some of the rank and file locals view foreigners as people who have taken jobs/opportunities away from locals.

I was with people who worked for my customer, and except for site seeing I didn't do much except work. I very much enjoyed my visit.

it's a place to break up your marriage if you are in one :) no empirical data, just experience of friends and people around them, and quite consistent

My friends who worked there (in their 20's and late 30's) both said it was great at first but boring as hell long term.