Ask HN: How do you deal with interruptions in the workplace?

I work as a Product Manager in a 100+ employees startup. I feel that during my work day I constantly get interrupted by colleagues through email, slack or just coming by my desk to make all sorts of questions. I also get this feedback from engineers and designers that feel unproductive some days due to office distractions. Do you have any special strategies or tools to deal with interruptions in the workplace?