I finished my undergrad in Electrical Engineering at the end of 2014, and since 2013 then I've been working on a startup that is soon going to fail.
I would like to apply for a Masters in 2017, and to strengthen my research profile in my resume, as well as earn letters of recommendation (which I sorely lack), I'm considering working under a professor/ at a lab for a year or so (in a research area similar to that I worked on at my startup).
However all research assistant/research associate positions seem to be advertised only towards students currently already studying in a graduate (masters/PhD) program.
Is it common/normal/acceptable for people to work in a university lab between their undergraduate and masters, like I wish to? If so, what are these positions usually called in the US/Europe, if not Research Assistantship?
To clarify, in addition to gaining experience, my main motivation would be to have a well known professor/someone at a well known lab recommend me, since I have a only one professor from my undergrad who would be willing to give me a strong letter of recommendation. I cannot expect anything from my present colleagues. Most applications seem to require 3 such letters.