A friend of mine, let's call him Jim, is a postdoc in Germany. Jim's contract is ending soon, and he talks to me often about this issue, so I decided to ask here. (Perhaps, this community can provide a piece of advice though I'm not directly involved.)
Jim publishes about one paper per year in a high-rank computer science conference or journal and does some teaching (seminars + teaching assistant for a lecture or teaching assistant in charge of a lecture). Otherwise, he is completely clean (no academic fraud, no convictions).
As far as I understand, Jim failed to integrate himself into the current research lab at a university paying him. (Probably, Jim took way more time than he expected to publish on his old topics unrelated to the activity of the lab and, AFAIK, is still not fully done with it.) Jim did everything necessary for the project which he was working on in this group and for required teaching; but the project ran out, and now the head of the group seems to try to get rid of Jim as soon as possible. The head is not very welcoming: the head does not finance conference travel despite earlier promises and does not answer e-mails.
So, given the fact that Jim is starting to apply for other positions, what are his chances on the job market in 1st world developed countries (North America, Western Europe, Israel, Australia, Japan, ...) where a good command of English and German is actually sufficient to live? It's not his first postdoc position, and it is not known whether Jim's current mentor (= the head of the lab) would actually send any reference letters for Jim at all when asked. How would Jim approach applying for tenure-track academic positions (or even industrial positions) if it is not known whether any reference letters would be actually sent out? (At certain stages, which is 1.5 till 5 years back, all Jim's previous mentors have confirmed to him that they will send the reference letters, but Jim is not sure whether they would actually send the letters, and Jim seems to have no chance even to find out whether the reference letters have really been sent or not.) What incentives (that Jim could trigger now) could cause a previous mentor to actually send a reference letter rather than simply replying "done" or moving the request to the trash bin? The situation is exacerbated by the fact that Jim promised to never ask for any reference letter from his PhD advisor. (It was a private promise for some private reasons, but still a valid one. Perhaps, Jim overestimated himself in the past or the like.) Even if all the prior mentors (except the PhD advisor and the current one), which are two or three, do actually send reference letters, but the current one is excluded, would it be worth to apply?
Each proper job application for a tenure-track position takes Jim a couple of full working days, so he is not wishing to invest his time into something which is doomed to fail.