[lumost]

when you're working you can always toss it off as "exploring my options". I had a period of 4 years where I traded jobs every 1.5 years. This strategy works well if you're starting at a company with a low bar and are working towards a top firm. Companies don't usually question it as long as you are moving up with each switch.

Once you cross the 5-7 years of experience mark companies will start to ask the question more pointedly as 1.5 years roughly corresponds with a performance review cycle. We all know engineers who have failed upwards or outwards for years but are competent enough to pass an interview and personable enough not to be fired. Senior level positions also tend to involve multi-year commitments that the company needs to know you're onboard for.