Actor-based programming is a well-established programming model for the development of concurrent and parallel systems. However, due to the asynchronous nature of its communication mechanism, it is often difficult to express coordination between multiple groups of actors. As a result, complex synchronization patterns are often difficult to express from within the actor model. The goal of this paper is to introduce a novel coordination model for actor-based programs. The model proposes advanced join-patterns over messages that improve the state of the art with four additional features: aggregation, sequencing, timing constraints, and transformations of sequences of messages. This paper also presents a prototype implementation of our model through a domain-specific language in Elixir.