One of the meanings of amateur is someone who does something for love. And, the word professional can be simply used to refer to someone who accomplished or skilful, regardless if they are paid or not. While the two words can be used an antonyms, I’m kind of in love with the idea of using them together.
I’m a Principal Engineering Manager at Microsoft working on Wunderlist in Berlin. A long time ago while working at Sun Microsystems, I created Tomcat and Ant and was instrumental in donating them to the Apache Software Foundation.