Spirit Airlines: a composable API network built for real-time operations
Over a multi-year partnership, Green Irony helped Spirit turn trapped, siloed data into a composable MuleSoft API network — the connective tissue behind real-time flight, crew, and guest operations.
THE CHALLENGE
Spirit's in-house teams faced what most established operators face: legacy systems, siloed data, and custom-built platforms that made shipping new capabilities slow. Most engineering time went to reactive firefighting, and the team managed only one or two major releases a year. Running an airline — 600+ daily flights across 80+ destinations — meant hundreds of systems had to share accurate data in near real time. They couldn't. The data wasn't missing; it was trapped.
What we built
Green Irony designed and delivered an API-led, event-driven architecture on MuleSoft — a network of composable, reusable APIs that became the connective tissue of the enterprise.
A reusable API network spanning flight ops, maintenance, crew, loyalty, and guest channels.
Event-driven, real-time data sharing so operational decisions — weather reroutes, crew assignments — happened instantly.
Customer-facing capabilities: self-service reservation management, upsells (bags, seat-upgrade bidding), and a superior chatbot experience across web, phone, and live support.
Purpose-built crew apps that surfaced real-time operations data to improve turn times and keep flights on schedule.
Outcomes
Over the course of the partnership, the API network became a digital twin of the business:
A network of 60+ connected applications and 130+ reusable APIs — a digital twin of the business.
5× developer productivity; new capabilities shipped in weeks instead of months.
Among the top-2 US carriers for on-time reliability, two years running.
300M+ API requests per month at peak scale.
“In an airline you have hundreds of systems talking to each other in near real time, sharing massive amounts of data and events. Rather than architect hundreds of interfaces between these systems, we opted for MuleSoft.”