Have you worked with high-load systems? What load indicators?

Yes, I have worked with high-load systems. The main performance indicators I monitored were:

• Requests per second (RPS/QPS) — how well the system can handle incoming traffic.
• Response time (latency) — delay in processing requests.
• Error rate — number of failed requests.
• Resource utilization — CPU, memory, disk, network.
• Throughput — volume of data processed by the system.

For monitoring, I used tools like Prometheus, Grafana, and also profiled bottlenecks and optimized critical sections of code and infrastructure.