Abstract: Methods and systems are presented for classifying an event conducted by a user based on historic event sequences conducted by the user. For a user whose interaction frequency with a service provider is below the threshold, using just an event sequence of the user to classify an event conducted by the user would not produce a result with an acceptable accuracy. Instead, the event sequence of the user and a set of event sequences of a set of users who are determined to be connected to the user is embedded within a portion of a transaction graph. The transaction graph represents transactions conducted among different users with the service provider. The portion of the transaction graph embedded with the event sequences is provided to a graph-based machine learning model. A classification is determined for the event of the user based on an output of the machine learning model.