receiving, by a computing device, set of webpage requests for access to a webpage, the set of webpage requests being associated with a set of users;

generating, by the computing device, a group-specific model corresponding to a user group of the set of users, the user group including users that share one or more characteristics, wherein the group-specific model is generated by training the group-specific model using historical data associated with the user group, wherein the group-specific model correlates particular webpage customizations to predicted user actions associated with the webpage, and wherein the group-specific model is configured to generate a prediction of a likelihood that a user in the user group will complete an action when the webpage includes a particular webpage customization;

generating, by the computing device, a first version of the webpage for users of the user group, the first version of the webpage including one or more customizations to the webpage selected based on predictions of the group-specific model;

facilitating, by the computing device, a transmission of the first version of the webpage to at least one user of the user group;

receiving, by the computing device, indications of instances of user interaction with the first version of the webpage;

retraining, by the computing device, the group-specific model by updating one or more weights of the model based on a comparison between predictions generated by the group-specific model and the indications of instances of user interaction with the first version of the webpage;

receiving, by the computing device, a request for access to the webpage, wherein the request is associated with a particular user of the user group;

generating, in response to the request and by the computing device, a second version of the webpage, the second version of the webpage including one or more alternate customizations to the webpage selected based on predictions of the retrained group-specific model, wherein the one or more alternate customizations increase the likelihood that a user will execute the action on the webpage; and

facilitating a transmission, by the computing device, of the second version of the webpage to the particular user.