Hmm, not sure i could advise based on your post. I work with my exh though, but totally different circs.
He was husband number 1 (now married to number 3).
We were childhood sweethearts, married at 18, divorced at 21. I left him.
Fast forward to age 33 and we ended up working for the same company - not totally a shock as we trained in a similar profession and both moved back to our home town when we both married spouse number 2 and had dc etc. It was a massive shock for us both as we hadn't seen each other since we split, rather acrimoniously age 21. Here we were, 12 years later, both re-married with dc. After a few awkward weeks we just kinda got on with it. It took another 2 years before we were actually honest with our colleagues about our past and were more friendly.
Fast forward another 8 years and we are still working for the same company, although both in different departments now. We are quite good friends now and work really well together. We both went through divorces from our second spouses within a few years of each other too.
If he is a genuine nice professional guy (as my ex is) then it shouldn't be a problem, if not then I imagine it could be hell!
whether exes working together could work out would really all depend on: how long you were together for; how long ago it was; how acrimonious the split was; etc.
man suddenly leaving his three kids & their mother alone rings a number of alarm bells, doesn't sound hopeful. I suppose it depends on how good the career opportunity is... if once-in-a-lifetime then I suppose it might be worth considering. if not then...
My ex is a nice mam who I was with for 6 years. I like him as a person and we split up for a lot of reasons but the underlying thing was that he wasn't that into me. I was recently approached about a really good job where he works and turned it down. It would just be too weird. However if I was currently unemployed I might have gone for it.