Thanks to everyone who have responded so far. Below are my replies.
@jubinjohn Thanks for your reply. I considered jobseeker visa option but I cannot leave my current job and stay in Germany. One of my concerns is whether my past contributions will be considered or not. In the worst case, let's assume they are not considered and that would mean I need to contribute again for 60 months to be eligible for Neiderlassungserlaubnis. But what happens to the current amount? Am I allowed to withdraw my share considering it is more than 2 years already? I would definitely like that they are taken into consideration as it shortens the time-frame significantly. Do you have any idea what I can do now or which documents I can submit that the past contributions are considered?
@someonesdaughter Thanks for your point-wise breakdown. My answers in the order of your questions.
a. Yes, I made a mistake, the first Germany should actually read Singapore.
b. I am considering to move back to Germany for good. I would like to settle down in a place where getting permanent residency is not up to chance like Singapore or USA. Instead of emigrating to a completely new country and start all over again with new rules and language, my first preference would like to move to Germany, as most of my uni friends are still there. At the moment, I am not able to make up my mind because its not clear to me whether I will start from scratch or not.
c. Yes, imo also the first one makes more sense but convincing my employer will be a task in itself. My employer may not be very cooperative on this move if they don't see value in moving me back to HQ. I believe, If I have something more concrete that works for the company coupled with a fact like "the DRV has advised that if I move to DE this year, I can still get my residency" etc.
d.On paper, my secondment contract ended in 2016. My residence permit expired in Oct 2013. Since then I have been traveling to Germany at least 2 times a year for work-related activities - trainings, meetings, conferences etc, on Schengen Visa. I hold a 3 year multiple entry Schengen visa at the moment that allows me to stay in Germany for 90 days. Yes, in 2012, I had applied to Aliens department for a letter stating I wlll be moving abroad for work and they allowed me. I still have that letter but I am not sure if it valid anymore because it allowed me to stay abroad for 1 year only. Will it make sense, if I speak to my employer and ask them to re-hire me in Germany as if they are "calling me back" instead of "new hire"? I am not sure whether they will do so as it may go against some laws in Germany since my German contract was already cancelled in 2017.
e. I am coming to Germany for a month to visit our teams in HQ and participate in product related trainings. I can enter Germany on my current Schengen Visa. I would like to have more clarity under which circumstances can the earlier periods be recognized and what I can do from my side to maximize the chances to make it happen?
f. A bit of a stretch but do you know any immigration lawyers on TT that I can reach out to incase the need arises?
@thegreatdivide - Thanks for your reply. I am looking at different job sites in Germany at the moment and trying to arrange interviews/visits during my stay.
@BradinBayern - Thanks for your reply. I am from India and currently working in the field of telecommunications. I haveworked in a variety of roles - pre-sales and project management and even product development and seeking jobs in related roles. If the company is willing to sponsor my permit, I will try probably have to come back to Singapore or India to get it.
I look forward to hear your further thoughts on the answers above.