In my part of Google, we use TPM for "Technical Program Managers" instead of PgM.
In general a TPM at Level N will have the technical skills of a Level N-1 SWE. So many TPM's have a CS background, and a good TPM is an amazing partner/resource for a TL to have, especially for a large, complex project which spans multiple teams and multiple departments.
For my Hybrid SMR project, my TPM came out of a HDD vendor, and was very well versed in the technologies of HDD internals. At the same time, he could navigate all of the bureaucracy and process to get test racks ordered, populated with servers, and installed in data centers. He could also create the capital budget plan and get it submitted and approved through finance so I could concentrate on the technology. A good TPM is critical for the success of a large projects; I couldn't have done it without him.
In general a TPM at Level N will have the technical skills of a Level N-1 SWE. So many TPM's have a CS background, and a good TPM is an amazing partner/resource for a TL to have, especially for a large, complex project which spans multiple teams and multiple departments.
For my Hybrid SMR project, my TPM came out of a HDD vendor, and was very well versed in the technologies of HDD internals. At the same time, he could navigate all of the bureaucracy and process to get test racks ordered, populated with servers, and installed in data centers. He could also create the capital budget plan and get it submitted and approved through finance so I could concentrate on the technology. A good TPM is critical for the success of a large projects; I couldn't have done it without him.