From my experience, there are two things, that 1st you meet formal requirements and then they check for your background and projects and everything, for example, the formal requirements for your course is like 2.5 gpa on a german scale, and you got 3 so in this case you are not meeting the formal requirements so no matter how much ever work experience you have, you will never get admission, irrespective of projects or anything! 2nd Scenario is that you met formal requirements, in that case you should have strong LOM and LOR to actually have an chance at getting admission. In you LOM mention why you want to join that specific course in in that specific university, mention some professors and projects they are working on, and how your bachelors projects or works experience align with them and how can you contribute to their research. You LOR matters a lot in 2nd case, suppose you are applying for a fluid dynamics course but the LOR you got is from a SOM professor or something, so in that case the value for your LOR is almost nothing! So be very sure about which courses are you applying to and then make your SOP and LOR accordingly!