In 2014, the AmLight network has evolved from a single layer 2 domain to a Software-Defined Network. The decision behind this change was made to i) improve networks operations efficiency, and to ii) add programmability to support network-aware applications. Results for both goals were seen in the first month of operation of the new network: i) Provisioning activities were reduced from days to minutes; and ii) Programmability was added as a service and used for a multi-domain SDN demonstration along the Internet2 Technology Exchange. Based on the results achieved, this paper was written to share AmLight’s experience of migrating a production single layer 2 domain to a Software-Defined Network with multi- domain and programmability support. Details of AmLight complexity, results and future work will be shared.