Do you use one productivity system for business and personal life, or a stack of different apps?

A lot of entrepreneurs seem to use a stack of tools to stay organized:

Calendar for appointments and events
Slack or Teams for communication
Notion for notes
Todoist or TickTick for tasks
Trello, Asana, or ClickUp for projects
ChatGPT or Claude for AI help

I’m curious how this works in real life.

Do you prefer having separate tools for separate parts of your life(personal and business), or have you found one main system that handles most of it?

Also curious about the cost side.

Roughly how much are you spending per month on productivity, planning, project management, notes, AI, and tools that help you run your business and personal life?

My own path went in the opposite direction.

I started with a pen-and-paper date-based system in 2014 to keep up with my freelancing work.

In 2016, I started building a digital version as a side project.
I launched an early version publicly in 2022.
Then in 2024 I went all in after I saw people getting interested in it.

Now it is the only productivity system I personally rely on for personal life, client work, agency work, content, and developing the app itself.

For me, having one place works better because business and personal life do not really happen in separate realities. They all compete for the same days, the same time, and the same energy.

But I know many people prefer a stack because each tool is better at one specific job.

So I’m curious:

What is your current productivity stack?
Do you use one main system or many apps?
And what is your rough monthly cost for all of it?