We occasionally have face to face workshops for committers or contributors, often at Zipkin sites. These are different than meetups in so far as they are very detailed and hands-on. In other words, they aren't best for anonymous drop-ins and even if they were space is often limited. These workshops don't follow a routine schedule, rather surface when key folks are near eachother with a common cause. Usually, we also chat on gitter while meeting face to face, sometimes keep a video feed open.