Aside from simple programs I wrote by hand-transcribing code from the "Basic Training" section of 3-2-1 Contact magazine when I was a kid in the '80s, I would say the first project I ever undertook on my own that had a meaningful impact on others was when I joined a code migration team when I was 25. It was 2003.

We had a simple migration log that we would need to fill out when we performed any work. It was a spreadsheet, and because Excel is a festering chunk of infected cat shit, the network-shared file would more often than not be locked by the last person to have the file open. One night after getting prompted to open the document read-only again, I decided I'd had it.

I went to a used computer store and paid $75 out of pocket for an old beater, brought it back to the office, hooked it to the network, installed Lunar Linux on it, and built a simple web-based logging application that used a bash-generated flat file backend. Two days later, I had it working well enough to show it to the team, and they unanimously agreed to switch to it, rather than continue to shove Excel's jagged metal dick up our asses.

My boss asked me where I was hosting it, as such an application in company space would have certainly required his approval to procure. I showed him the completely unauthorized Linux machine(remember, this was 2003, when fortune 500 corporations, such as my employer, believed Ballmer's FUD-spew about Linux being a "virus" was real and not nonsense at all), and he didn't even hesitate to back me up and promise to tell the network security gestapo to fuck off if they ever came knocking. They never did.

I was later informed that the team continued to use the application for about five years after I left.

DREAM 1
(my comments look like this)

A kikiland metro system. It's extradimensional and shapeshifting. When you enter it, it adapts to your needs. The people inside (they're probably just vinyl shells), the social circumstances, all generated for you.
When you enter it, it knows where you want to go. It spawns exactly one train just for you. It will be the first, it will be the last. You have to catch it to go where you need. If you miss it, there will be no more trains, and you have to wait till the metro station closes for the night and reopens.
It's always you entering, catching the train that arrives just in time, going to where you need to go and exiting.
Because of its extradimensional nature, you cannot agree to meet someone there — every person has their own personal metro generated just for them every time, with exactly one train going exactly to the station you need.

It's used by BLA as a form of control. When they don't want you to go somewhere, the train won't spawn. Or, it might diverge and get you to some other place. It isn't known whether the map can be altered on the fly or not. So far, the consensus is that the map is persistent and is a public knowledge, and it's just the metro itself that is extradimensional. But, no one ever saw the real metro in its real form, and not the top layer that protrudes into the three-dimensional world you can interact with. It might be the case that they can make people disappear by creating ad-hoc stations that don't intersect with the real world, trapping them in places that are nowhere in particular.

(it took seeing BLA once in one dream to make all the following dreams include them. Sigh.)

Kikiland also has a school, and it always had it. I befriended a chemistry teacher there. His classroom is small — exactly as deep as other classrooms, but really narrow. There are no desks there, just his desk and some bookshelves. Chemistry isn't a priority there — his class exists only because it should. No one attends it. This is why he was so pleased to meet me. Despite his classroom being located on a busy floor, its door is overlooked by students, and NO ONE ever enters it. He just sits there, waiting for students to arrive, but they never do.
He has a secret, though, because of course he does. In the game Control, if you complete the main storyline before you complete some side quests, one of the main characters will be sitting in the C-suit hall, doing her things, waiting for you to come and talk to her. But at the same time, she will be waiting for you deep down the oldest house's mines, again, just sitting there, waiting for you to take the quest. This teacher is the same.

If you have a good relationship with him, and you attend his class, the classroom will change to a tunnel entrance, with him being the security guard. He's your friend, he'll let you in. It looks like Fallout's vault entrance. THIS is how you enter the REAL kikiland metro. (Dream 1 ends here.)

Episode 2
Tiny waterborne rat puppies whose mouth is their entire face unfolding like a piece of paper with teeth covering it as a grid. (I wrote about them already, but here they are again.) They are _tiny_, a bit like tadpoles. Also, like tadpoles, they die if you touch them out of water. As I was flying over some mountain resort (I routinely fly in my dreams, but it feels more like a very low gravity falling I can control, like using a parachute in GTA San Andreas), I dumped them to a location that resembled the garden level of Prince of Persia: Warrior Within for my cat to eat. It didn't want to.