Will there be difficulties or problems when processing a large number of users with a basic system architecture?

Yes, with a basic system architecture, issues can arise when handling a large number of users. The main difficulties are:

• Scalability: the basic architecture may not support horizontal scaling, which limits the number of users served simultaneously.
• Performance: bottlenecks in request processing, locks, or inefficient resource utilization can lead to delays.
• Resilience: lack of failover mechanisms and load balancing can cause failures during peak loads.

To address these problems, distributed systems, caching, load balancers, and architecture optimization are typically used.