Spotify may be synonymous with music streaming, but it’s also got a wildly popular developer-tool side-hustle called “Backstage.” Backstage is an open source project that helps companies build their own internal developer portals: a catalog of their developer tools along with quick visualizations of the work the tools have done, and other metrics. But like many open-source projects, Backstage is a build-it-yourself option. Israeli startup Port has been gaining big-name customers like GitHub, Bri...