Can I work as a software engineer and be a PhD student? I'm a master student, my master's background is about IT, signal processing, and Telecommunications. It's a "research master", which means that we're trained more to do research than be an IT engineers/specialists.

I've made my choice because I want to do research, but It is also important for me to work after my masters graduation, some of my professors always say that it's very difficult, even impossible to do those two things together. So I'd like some more advice. Here are my questions:


Is it practically possible to do research and work?
Is it a good idea to work for a year or two after my masters, and start a PhD after that?
What kind of internships can I do, and how long should they be, so I can apply to IT companies?


PS: I've some background ans skills in Java technologies, software design, web development, and basic knowledge in networks.
I did combine PhD and work for 4 years, so, theoretically - yes, it's possible. But I didn't like the process because I wasn't fully invested in either activity. It also significantly delayed my defense. It depends on how productive you are. At times you will be facing certain deadlines and will be feeling torn between two major activities. 

I think you should go ahead with PhD if you are serious about it. It will take some 3-6 years of your time, so why to postpone it? I think it's totally possible to get internships at summer time and you may have to develop software as a part of your research, so you'll be practicing your skills. 

You can also consider free-lance work so that you have more control over your time.