Locust is a load-testing tool that turns plain Python scripts into swarms of simulated users, so you can find out exactly how much traffic your service survives before it falls over. You model real behavior with ordinary Python: classes describe user types, tasks carry weights, and waits plus conditional logic mimic how people actually browse, log in, and check out. The web interface starts the swarm, charts requests per second, response times, and failures as they happen, and lets you raise or lower the load mid-run the moment a bottleneck appears. One machine is rarely the limit: a master process coordinates worker processes across as many machines as you can give it, and every worker runs thousands of greenlet users without thread overhead. HTTP is the home turf, but custom clients let the same scripts load-test WebSockets, gRPC, databases, message queues, or any protocol you can call from Python. Custom load shapes bend the user curve into steps, waves, or double peaks that mirror launches and flash sales instead of a flat ramp. Results export as CSV data and standalone HTML reports for the team, stats can stream into TimescaleDB and Grafana during long runs, and headless mode drops the whole test into CI pipelines. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.