Has anyone implemented multi-tenant Marketo instance ?
Look into (and add to your subscription) Partitions and Workspaces.
which we are planning to use API instead of native Marketo SFDC sync
This is almost certainly a doomed idea. What kind of due diligence did you do to come to this conclusion? No experienced Marketo consultancy would make this suggestion.
Migration is a huge undertaking...I highly recommend hiring Marketo Pro Services or an outside agency to manage this. It's the foundation of your instance, and it's too important to do by yourself.
Hi Ashok, as suggested by Amy you can take help from Marketo Pro services and in case you need help in your Migration plan I would be happy to connect with you and discuss your requirement and share our recommendation. Feel free to write me at Vikramt@grazitti.com
Vikram, direct advertising isn't allowed per Community rules.
Things to consider: decide early if you want to transfer lead activity history from Hubspot to Marketo - you'll need an experienced developer to work with Hubspot API to export this data (pretty labor intensive) and Marketo API to re-import it into Marketo as custom activity records. Also if you choose to transfer activity log history, check the size of your Hubspot lead database - Hubspot API limit is 40K calls per day and If you need email history too, you won't be able to batch part of your calls. We learned that the hard way. That might take a long while for a DB the size of >800K.
Next, the templates-> unique landing pages logic as it is done in Marketo is different in Hubspot. You'll need to rework templates.
Hubspot doesn't support dynamic values for form fields based on URL. So 1 to 1 form transfer would be unrecommended, rethinking the logic behind the forms is highly advised.
As for multi-tenant solution, we have several semi-independent regional offices from different parts of the world working in the same Marketo instance. All leads originally go to a default partition and get re-assigned from there to appropriate partition based on Country & other fields. We aren't doing duplicates though, we move leads around in Marketo instead. That's probably suboptimal if your different Marketo tenants service the same region, but would work pretty well if your tenants have little/no overlap in terms of business due to servicing different areas.
As for SFDC integration, not sure why you are not going with a native SFDC integration, it's almost always either a bad idea or a terrible idea. If you need to connect several SFDC instances to a single Marketo instance, I suggest to sync Marketo to a Master SFDC instance and then o use data loader to push data from Master SFDC to various slave SFDC instances you might be using.