50x Faster and 100x Happier: How Wix Reinvented Integration Testing

Why Tests Matter in Software Engineering
Integration tests are essential for verifying real-world interactions between system components. However, running and maintaining them — especially with Docker-based setups — often leads to slow feedback, flakiness, and complex configuration headaches.

Wix engineers tackled this challenge and developed a new approach that cuts testing time by more than 50x, all while streamlining the workflow for developers.

Highlights from the Wix Solution

• In-Memory Integration Testing:
  Wix replaced external dependencies (like databases and RPC services) with in-memory implementations for testing. This avoids slow Docker containers, reduces infrastructure overhead, and increases reliability.
• Hexagonal Architecture:
  Business logic is decoupled from infrastructure concerns using well-defined ports and adapters. This makes it simple to switch between real and in-memory collaborators in tests, preserving the consistency between test and production code.
• App Context Builder:
  Dependency wiring is managed automatically, ensuring test environments stay in sync with production without extra developer effort.

Benchmarks and Impact

• Nearly 100% of new Wix integration tests now use this method.
• Feedback cycles are much shorter, making it easier to detect and fix issues early.
• Flakiness and configuration errors common in Docker-based tests are largely eliminated.

Read the Full Engineering Deep-Dive

Curious about the architectural patterns, implementation details, and performance benchmarks behind this approach?

Check out the full engineering post here:
50x Faster and 100x Happier: How Wix Reinvented Integration Testing