Reached out to their recruiter on LinkedIn. Was pleasantly surprised at first as they were moving fast - phone conversation with the recruiter 2 days after the initial contact and with a senior manager the next day. Both conversations went ok (as far as I'm concerned) as the immediate feedback during the calls was positive.
Sounded like the next step was a "homework" type assignment writing a small project using GOSU which is a JVM language Guidewire developed. Being a fan of Scala and Clojure I was actually looking forward to this, installed GOSU locally and did some prototyping with their SparkGS framework ;)
Haven't heard back from Guidewire, attempted to get feedback from their recruiting team few days after my last conversation with them to no avail, hence the reason for the "negative" overall experience rating.