I have recently developed an interest in a hot topic of computer science and I would like to pursue a master's degree in that topic. Looking at the available grad school programs and their admissions process they all (very understandably) require recommendation letters.
The issue is that I graduated 6 years ago and not expecting to ever need a recommendation letter for further academic development I have not kept any connections with previous professors. I could try to contact some of them who I had a good relationship with back then, but I believe the most I would get now is either a rejection or a run of the mill "This student was punctual and had good grades" type of letter.
In the past 6 years I have served in the army for a year and worked in the industry for the next 5. I believe I have a good chance of getting a good recommendation letter from past and current managers.
My question is this. Do I absolutely need recommendation letters from professors in order to get a place at a grad school program or is anybody who I have worked under a good reference? How do admissions committees look upon recommendation letters by non academics?
I am not looking for a career in academia. I want to apply the knowledge I will get in the industry. (And I intend to put this in my motivation letter)
If it makes any difference I am interested in European universities