diff --git a/README.md b/README.md
index 4230491..1acda88 100644
--- a/README.md
+++ b/README.md
@@ -5,6 +5,14 @@ This project aims to create the necessary building blocks in order to allow coll
 
 ## Architecture
 
+The architecture should use existing building blocks where possible.
+For details, please see the diagram below. It shows existing apps (green), parts with only partial solutions so far (orange) and aspects which would need to be designed and developed mostly from scratch (red).
+
+At the moment, the [HealthConnect API](https://developer.android.com/health-and-fitness/health-connect) is seen as a central part for integration and synchronisation.
+Supporting the HealthConnect API allows to integrate devices for which FLOSS app do not exist yet. It also makes the migration easier, since you can migrate step-by-step to a more privacy friendly stack.
+
+However, alternative solutions to the HealthConnect API are more than welcome.
+
 ```mermaid
 flowchart LR
   scale(("bathroom<br>scale"))