I am starting the design of a somewhat large enterprise platform in Python, and was wondering if you guys can give me some advice as to how to organize the various components and which packages would help achieve the goals of scalability, maintainability, and reliability.

The system is basically a service that collects data from various outside sources, with each outside source having its own separate application. These applications would poll a central database and get any requests that have been submitted to perform on the external source.

There will be a main website and REST/SOAP API that should also have access to the central data service.

My initial thought was to use Django for the web site, web service and data access layer (using its built-in ORM), and then the outside source applications can use the web service(s) to get the information they need to process the request and save the results. Using this method would allow me to have multiple instances of the service applications running on the same or different machines to balance out the load. Are there more elegant means of accomplishing this? i've heard of messaging systems such as MQ, would something like that be beneficial in this scenario?

My other thought was to use a completely separate data service not based on Django, and use some kind of remoting or remote objects (in they exist in Python) to interact with the data model. The downside here would be with the website which would become much slower if it had to push all of its data requests through a second layer.

I would love to hear what other developers have come up with to achieve these goals in the most flexible way possible.