My team at Microsoft builds the query federation engine that's behind the Power Query addin for Excel. We're a team of eight that's looking to add 2-3 devs. Some links to job descriptions:

https://careers.microsoft.com/jobdetails.aspx?jid=162282

https://careers.microsoft.com/jobdetails.aspx?jid=162286

https://careers.microsoft.com/jobdetails.aspx?jid=162294