This has always been a difficult challenge when job hunting for me, and I'd be curious to hear how you dealt with this in your application process.

Nearly every job offer I've encountered expects a response within a few days. In practice, I'm usually interviewing at multiple places and at different stages of the interview process at each.

When engaging with so many companies, how in the world do you synchronize all the offers + interviews?

For nearly every offer I've received, I feel that the company might take objection or even not allow me more than 3-4 days to decide on an offer.

Also, how do you manage other companies sensing that you're 'playing the field' with them (which can easily become apparent, when you're employing these tactics)? That's generally not positive for goodwill with someone you might eventually be working directly + closely with.