I actually use Microsoft TODO now, for all the various features. But important things I do back up onto the calendar too.
I disabled all useless notification and now on my lock screen I only see things I need to process.
I get message from someone that I don't want to reply right away? I just leave that notification on screen.
All reminders, mails and various other notifications (my washing machine pings me when its done) stay on my screen until I do what needs to be done.
This together with using trello as personal scrum board really helped me todo more.
Most apps have too many events to be worth notifications. Looking at you Slack. Those are better handled by a periodic polling rather than push notifications.
My phone notifications were useless until I did the same.
Deny notification access by default and "poll" your inbox/chats/etc with a calendar reminder 1, 3, or 5 times per day.
I have tried this, but it flirts with a worse outcome: alarm fatigue. If I start ignoring one task, that risks bleeding over to another task. If I reflexively snooze "call mom" today then the chance that I snooze "write report" tomorrow is nonzero. Which, like you say, is unworkable as an adult in tech.
For me, physical notes work better than electronic ones. Push notifications are a pox on productivity, and I find that if I limit their use to (would-be) emergencies, they're super effective. But if they become noise, my entire computer risks turning into a work-free zone.
Because of alarm fatigue, I avoid adding TODOs to the calendar that are not real TODOs. Something like "write report" I don't really need on my calendar. I know I need to do it. I'm talking with the client. Etc.
Something like "[Friend name] should be back from [place name] by now. Call him!" matches it better. The type of things that would otherwise slip by.
I do believe calendar worked better for me because I'm not operating over "tasks" but over "time blocks". This way I'm more efficient, and I'm progressively getting better at estimating how much time I need to allocate for a specific task. It's a broader perspective than the atomic "task" and it feels more intuitive to me to operate at this layer. HBR has a great article that discusses some of the things I said (https://hbr.org/2012/01/to-do-lists-dont-work).
The only person I currently found discussing another way of looking at willpower that completely resonated with my experience was Scott Young (https://www.scotthyoung.com/blog/2018/02/09/rethinking-disci...).
Excerpt:
"Needless to say, meditating requires a lot of self-discipline. But is it the kind of self-discipline that gets consumed as a resource?
At first, that answer seemed obvious to me: the longer a meditation session went on, the more willpower I’d need to resist the urge to quit and go do something else. My back and legs would hurt, so I’d want to change my posture. I’d want to daydream about something else, engage in a little mental theatre imagining this scenario or that one. Yet—according to the technique—whenever this happens you’re to remind yourself you’re here to work and shift your focus back onto something happening right now.
As the days wore on, however, I started to notice something about my own self-discipline that seemed to contradict the resource metaphor. Sitting still and doing meditation was hard, but it was hard to the degree to which I was somewhere else. If my attention was fully focused on what I was doing, and not on, say, thinking to myself about how long this will last and when I’ll be free, the act got a lot easier. The longer attention was paid to the meditation without these interruptions, the easier it got.
This suggests a very different model of willpower, one based on attention and mental habit patterns, instead of a consumable resource."
Make a calendar event. Make it repeat just often enough to be annoying. If necessary (e.g., taxes) make a couple more that are much more forceful with their language near an actual deadline.
That's it. When you're done, delete the repeating calendar thing.
It feels awesome deleting an infinite set of repeating events in the future. It's essentially self-induced negative reinforcement on a platform you cannot really ignore as an adult working in technology.