An Adobe Marketo Engage Architect notices that the smart campaigns run slowly.

The steps that the Architect should perform to scale the campaign execution are to move the Send Alert step to first for campaigns sending alerts, and to use batch campaign scheduler instead of Advanced Wait Properties for batch campaigns. These steps will help the Architect to improve the speed and efficiency of the smart campaigns, as well as reduce the backlog in the campaign queue. Moving the Send Alert step to first will ensure that alerts are sent immediately without waiting for other flow steps or triggers, which can cause delays or errors. Using batch campaign scheduler instead of Advanced Wait Properties will allow the Architect to schedule batch campaigns at a specific date and time, instead of using a wait step that can clog up the queue or run at suboptimal times.

References: https://docs.marketo.com/display/public/DOCS/Smart+Campaigns+Overview https://docs.marketo.com/display/public/DOCS/Schedule+a+Batch+Campaign https://docs.marketo.com/display/public/DOCS/Wait+Flow+Action