I am looking to apply for a professional masters program in computer science (M.E. in Computer Science). This program is designed to for the working software engineer and thus not advised for those interested in doing computer science research in academia. As part of this, I am going to need to submit 3 letters of recommendation. It has been a few years since I graduated with my bachelors and I did not have a significant relationship with any of the professors in my undergraduate program. Thus, I would not be comfortable asking them for a letter of recommendation.
I am now working and I am highly regarded at work. I am confident that I could get very strong letters from various managers that I have worked with at my company. Will 3 strong letters of recommendation from these individuals be enough? How will they be weighed against a less strong letter from an undergrad professor?