Had a manager last year who was brilliant but ran on chaos. No agenda for 1:1s, constantly forgot context from the previous week, would agree to things in the meeting and then deny it two weeks later. Not malicious, just scattered.
You have two choices: let it grind you down, or treat it as a sales problem. I picked sales.
Own the 1:1 structure yourself. I sent a short agenda before every meeting. Not a request for one, just mine. 'Planned topics: status on X, blocker on Y, decision needed on Z.' He would sometimes add things, more often we just ran it. Took me 10 minutes. Saved hours of drift.
Confirm decisions in writing. After any conversation where something was agreed: I'd send a one-liner on Slack. 'Quick recap: we're going with option A on the auth flow, I'll brief the team.' Takes 30 seconds. Now there's a record and he's confirmed it. This one alone saved me from two 'I never said that' moments.
Build your own paper trail. Weekly status notes, even if no one reads them. Summarize what you shipped, what's blocked, what decisions you're waiting on. When review time came, I had 12 months of receipts. My manager had to write my review based on my own notes because he genuinely didn't remember half of it.
Don't try to change them. I spent the first month frustrated that he wasn't more organized. That's time I'll never get back. Some people run on chaos and function well anyway. Once I stopped needing him to be different, things got easier.
The downside of all this: it's extra work you shouldn't have to do. It's real. The upside: you get very good at managing up, which is a skill that transfers everywhere. I'm better at working with C-suite at my current company partly because I trained on a chaotic manager.
Anyone dealt with a manager who was disorganized AND not responsive? That combo is harder.