Uber developed DragonCrawl, an innovative AI-powered mobile testing system that uses a small language model (110M parameters) to automate app testing across multiple languages and cities. The system addressed critical challenges in mobile testing, including high maintenance costs and scalability issues across Uber's global operations. Using an MPNet-based architecture with a retriever-ranker approach, DragonCrawl achieved 99%+ stability in production, successfully operated in 85 out of 89 tested cities, and demonstrated remarkable adaptability to UI changes without requiring manual updates. The system proved particularly valuable by blocking ten high-priority bugs from reaching customers while significantly reducing developer maintenance time. Most notably, DragonCrawl exhibited human-like problem-solving behaviors, such as retrying failed operations and implementing creative solutions like app restarts to overcome temporary issues.
