Hi Lars,
I’ll offer some counsel based on a decade of observing projects similar to these. The goal of having a dashboard like product to track everything has attracted dozens (perhaps even hundreds) of programmers. Sometimes these were commercial projects, sometimes they were hobbyist or community or more generally open projects. A few have survived. Zenobase, exist.io, and Gyroscope are the most well known examples in the QS Community. (Q: Who am I leaving out?) In general this has proven to be much more difficult than most people realize when they begin, due to heterogeneity on both sides of the system: users have more divergent needs than is obvious from the beginning; and, data flows from services and apps are more idiosyncratic and less stable than is obvious. You have to be prepared for a long haul. Maybe you have source of income that allows you to tinker freely for years; that’s great. Or perhaps you have a startup intensity that allows you to raise money to support the development and customer acquisition phase. That can also work. Or maybe you have a specific use case you envision, a problem to solve for people who have no other solution and will pay you for your early versions and support you as you go forward incrementally. Also can work! But I encourage you to ask the question: How does this survive for, say, three years in a way that allows me to devote significant development and support time to it.
An alternative approach is to contribute to the development of an open collection of Jupyter notebooks. See this section of Open Humans for some inspiration: https://exploratory.openhumans.org/.
Open Humans can manage the user authorization workflow. Then you can build your own
dashboards and share them in a variety of ways, as well as run them at a URL and allow authorized users to operate the dashboard with their own data.
This doesn’t work for supporting a commercial path of the conventional sort, probably, but it gives you access to some good technical and platform capacity, as well as to a small but very knowledgeable group of potential collaborators.
Here are some of the notebooks currently available, if you want to browse examples: https://exploratory.openhumans.org/notebooks/