Ginger Grant gives us an overview of where we can use Apache Spark in Microsoft Fabric:
If you have used Spark in Azure Synapse, prepare to be pleasantly surprised with the compute experience in Microsoft Fabric as Spark compute starts a lot faster because the underlying technology has changed. The Data Engineering and Data Science Fabric experiences include a managed Spark compute, which like previous Spark compute charges you when it is in use. The difference is the nodes are reserved for you, rather than allocated when you start the compute which results in compute starting in 30 seconds or less versus the 4 minutes of waiting it takes for Azure Synapse compute to start. If you have different capacity needs that a default managed Spark compute will not provide, you can always create a custom pool. Custom pools are created in a specific workspace, so you will need Administrator permissions on the workspace to create them. You can choose to make the new pool your default pool as well, so it will be what starts in the workspace.
Read on for more of Ginger’s thoughts on the matter, including how you can use Copilot in Microsoft Fabric (if you pay for it) to help generate Spark code.