Tell about the architecture of systems implemented in your previous projects.

In previous projects, system architecture was predominantly multi-layered (3-tier):

• Presentation Layer — user interface (e.g., web application on Flask or Django).
• Business Logic Layer — data processing and business rules implemented in Python.
• Data Access Layer — interaction with the database (PostgreSQL, MongoDB).

There were also microservices architectures, where individual components (services) interacted via REST API or message queue (RabbitMQ). This approach allowed for more flexible system scaling and development.