1. A computer-implemented method for a multi-tenant computing system, comprising: receiving, using a parent process, a request at a multi-tenant platform to perform an operation on behalf of a tenant of the multi-tenant platform that impacts at least one resource of the multi-tenant platform; and responsive to analyzing the request to determine a customization associated with the operation associated with the tenant, initiating a child process for the tenant to perform the customization at the multi-tenant platform; isolating the child process from other processes associated with other tenants of the multi-tenant platform, wherein the isolating comprises defining a first environment, for the child process, that is isolated from (i) a second environment of a core logic of the multi-tenant platform and (ii) environments of customizations for the other tenants, wherein each environment is associated with same functionalities and different memory; assigning at least one limitation on usage of the at least one resource by the child process; controlling execution of the child process, in the first environment, based on the limitation on usage of the resource, wherein the controlling the execution comprises (i) restricting the child process from accessing at least some data of the second environment and from accessing at least some data of the environments of customizations for the other tenants and (ii) restricting the child process from consuming more than a threshold of the resource defined by the limitation; monitoring use of the at least one resource by the child process; and responsive to determining that the monitored use exceeds the threshold, assigning a further limitation on usage of the resource by the child process.