The architecture is described by a simple block diagram.
Each box stands for multiple algorithms that fulfill a specific task.
Each database provides a well defined interface to load and to store data. The algorithms use this interface to retrieve and update the data. Moreover external application can read the data through the same interfaces.
Step 1 is under the responsibility of WP4, step 2 will be managed by WP2, Step 3 by WP3 and Step 4 by WP5.