Methods, systems, and devices for data processing within a distributed data system are described. In a multi-tenant distributed data system, a provider may supply executable code for processing data using declarative processing instructions received from a tenant. For example, a tenant may provide tenant-specific processing instructions for a requested set of data. The processing instructions may indicate input information (e.g., a data structure, tenant-specific fields, etc.), transformation information (e.g., from a set of pre-defined transformations), and output information. The provider-supplied code may use the tenant-specific processing instructions to process and generate the requested set of data, where the code may be executed by multiple nodes within the system. As such, the code executed by multiple nodes may utilize the input information, transformation information, and output information from the tenant-specific processing instructions to generate the requested data and provide the data to the tenant.