I won't say I'm 'doing well' per se since I'm still quite junior but don't start w a tier 1 for IP, I got exposure from a very small and new firm, learnt everything including basic filing work, paid well. Start small and work your way up, you learn so much more.
Ik of people who started off at boutique IP firms, got some good experience and then later(3-4 years later, sometimes earlier, depends on you tbh) either joined a tier 1 practice or got a good in house position, so yes I'd say it's possible.
I'm also starting off at a boutique firm soon.
P.S. I think I've seen you around in some of the IP specific threads on LI.
For IP, it is actually better to start from a small firm. Most Tier 1's do not have a thriving IPR practice, and any learning there would be minimal. The trend is in fact to work 2-3 years in a boutique place and then move ahead.
I'm also starting off at a boutique firm soon.
P.S. I think I've seen you around in some of the IP specific threads on LI.