The Challenge

Game launches are high-stakes events. Millions of players hit APIs within hours, and any failure means lost revenue, negative reviews, and damage to the brand. Our client’s existing load testing solution was built on a platform Microsoft had deprecated, leaving them without reliable tools to validate their infrastructure could handle launch-day traffic.

The critical constraint: they had 20 years of C# load tests representing millions of dollars in development investment. Any replacement had to preserve this work while modernizing everything around it.

Our Approach

Hybrid Architecture

We selected Locust as the orchestration controller for its flexibility and scalability, but with a critical twist: we created custom C# workers that are fully Locust-compatible. This preserved every existing test while giving them modern orchestration, scaling, and observability.

Phased Delivery

The project evolved through clear milestones:

1. MVP: Basic Locust controller + C# worker proving the architecture
2. Alpha: Docker Swarm containerization, automated deployment
3. Beta: Advanced load patterns, React-based management UI
4. V1: Metrics visualization pipeline with OpenTelemetry + Grafana
5. V1.1: Platform refinements based on real-world usage

Scale Through Containerization

Docker Swarm orchestration enabled scaling to 10 million concurrent simulated users. The architecture distributes load generation across worker nodes while maintaining centralized control and metrics collection.

The Results

The platform is now the client’s primary load testing infrastructure, supporting game launches that need to handle millions of players on short notice.

• 10M+ concurrent user capacity achieved through container orchestration
• Zero test rewrites required - all existing C# tests work unchanged
• Real-time metrics via OpenTelemetry and Grafana dashboards
• Self-service UI enabling teams to run tests without engineering support