'I am not really looking, just checking what's out there'
These days, I have been building my own team at the mighty Impala Search and I am starting to see why my clients have a problem with such an interview answer.
Long story short, imagine going on a first date. He/she could be the one! After days of excitement and anticipation, it is date time! A romantic restaurant, candles, Barry White...
Then, your date arrives, and opens with: 'Well I am in a happy relationship but I also decided to see 25 other people just to see what is out there.'
Most software engineers interviewing are not actively looking for the next career step. Nothing wrong with that.
However, ask yourself the below questions:
1. Am I dissatisfied with my current position?
2. Is there, specifically, anything that could be better in my current position (money aside)?
3. Can I see myself investing 6/7 hours of my free time in an interview process?
If you are looking at three NOs, then please do not waste your time interviewing. Life is way too short!
If there is a YES somewhere there, then seeing other companies makes perfect sense. You are not 'actively looking', true, however, there is actually a reason why you are interviewing.
Just be honest with the interviewer and tell them that :)