You are tasked with designing the backend for a new application that requires two distinct data stores:

1. User Profile Store: This store needs to hold user profile data, which has flexible and evolving attributes. New fields may be added frequently, and not all users will have the same set of attributes.
2. Transactional Banking Ledger: This store needs to manage financial transactions, requiring high consistency, atomicity, and strong data integrity guarantees for critical monetary operations.

For each of these features, recommend a suitable database type (e.g., Relational SQL, Document NoSQL, Key-Value NoSQL, Graph NoSQL, Column-Family NoSQL) and thoroughly justify your choice. Your justification should explain the core strengths of the recommended database model that make it ideal for the specific use case, highlighting why other types might be less suitable. Focus on concepts like schema flexibility, ACID properties, scalability, and data relationships.