Creation and execution of customized code for a data processing platform

A method of executing computer-readable code for interaction with one or more data resources on a data processing platform, the method performed using one or more processors, comprising: receiving a request message including an identifier identifying executable code stored in a data repository; determining, using the identifier, an execution environment of a plurality of stored execution environments mapped to the identified executable code, wherein determining the execution environment mapped to the identified executable code comprises: accessing mapping data identifying a mapping between the identifier and the execution environment of the plurality of stored execution environments, the mapping data including configuration data associated with the identifier, wherein the configuration data identifies one or more convention-based data libraries particular to the execution environment; configuring the determined execution environment to access the one or more convention-based data libraries during execution; executing the identified executable code using the determined execution environment; and passing requests made with the identified executable code to the one or more data resources via a proxy.