Sometimes the architecture is not designed by a single person. Sometimes it is a group. Sometimes it evolves from every-developer-does-it. Sometimes the role sw

Sometimes the architecture is not designed by a single person. Sometimes it is a group. Sometimes it evolves from every-developer-does-it. Sometimes the role switches quickly from person to person. I don't know scientific studies to compare the approaches. Usually everbody just agrees that ideally one person should do it all. It is usually easy to identify architectural decisions. You can then find out who made that decision and thus figure out who is the architect. For example, in a web project: Who decided to build microservices vs a monolith? Who chose the database technology (PostgreSQL vs MySQL vs MongoDB vs ...)? Who chose the cloud platform? Who introduces external SaaS products? Who split up the big thing into pieces for different teams?