How do you evaluate the scale of the largest system: number of users, integrations, data volumes, number of functional requirements?

The assessment of the scale of a large system typically includes several key parameters:

• Number of users: active, registered, peak load — this affects performance and scalability requirements.
• Number of integrations: external services, APIs, databases — the more integrations, the more complex support and testing become.
• Data volumes: size and growth of data, storage and processing requirements, which influence storage and processing architecture.
• Number of functional requirements: diversity and complexity of functions, which impact development and support complexity.

Metrics such as the number of transactions per second, stored data volumes in TB, and the number of active users during peak hours can be used for assessment. It is also important to consider requirements for fault tolerance, security, and response time.

This comprehensive approach helps understand the load and complexity of the system, which is important for choosing architecture and technologies.