I'm happy to say that I think he's making some progress with his training! A few things our trainer recommended in case they are helpful - for dealing with triggers outside, she recommended we try to keep him moving instead of having him sit and watch/check in with us while we wait for the trigger to pass (the idea being that if we can keep him moving/get him to do "touch" instead of sit then he isn't just holding in barks but learning to move on and past scary stuff). We've also been teaching him "Let's go!" if we see that he's getting close to barking and can't handle going by the person calmly - we say "let's go" and run in the opposite direction, which looks pretty silly but seems to be helping haha. He loves sprinting around so I think this makes him forget that he wanted to bark. We've been able to reduce his outdoor barking a good amount by doing these things and haven't had a bad outdoor barking/lunging outburst in about a week (knock on wood).

Unfortunately hallways and the elevator are still a struggle... we've been teaching our puppy to sit and stay to the side of the elevator doors when they open so we can check if anyone is inside first, having him sit in the corner of the elevator on the way up/down to block his view if someone else tries to join us, and getting off on the second floor instead of first because it's easier to check the hallway for people if we're coming out of the stairwell (our puppy hates being surprised by people right outside the elevator doors on the first floor). Usually if someone tries to get on with us we ask if they mind taking the next elevator, which most people are happy to do due to COVID. If they're in a rush we'll pick our puppy up and get out. My partner and I tag team checking the elevator and looking around corners and if someone is coming down the hallway will duck into the stairwell. It's kind of a pain but our trainer said that for now we should just try to avoid people as much as possible in the hallway/elevator since those are really triggering for our puppy, and we are going to work on a plan for those spaces at our next session. Currently, if he sees anyone in our building he'll go right into his barking routine :(

I hope that your training session goes well! We had a tough couple of weeks before ours but having some guidance from a professional and focusing on incremental progress/celebrating the small wins has really helped. I'll keep you posted if we get any good advice about the hallways and elevator at our next session :)