GardenCityRubyConference presentation. Abstract: In 2012 Flipkart's supply chain system was re-built as a service oriented architecture with Ruby at its core. This talk will cover our experiences designing, building and scaling a mission-critical Ruby-based system where data integrity and performance is vital. - Dealing with cross-service transaction integrity - JRuby - the good, bad & ugly - Coordinating gem upgrades across multiple services - Performance tuning to get predictable response times - taming queries, external calls, GC, locks - Monitoring & profiling production systems - Ruby app servers: Trinidad vs Passenger vs Unicorn - Challenges in ramping up teams on Ruby