There's a related Q here about some other past job claims about him, but there's also, e.g. in the Daily Mail:

Barack Obama's former director of the National Security Council has been unmasked as a man seen unleashing an Islamophobic attack on a street vendor.

It's then partially repeated that

Seldowitz [...] worked in the Obama administration.

Or https://www.ghlinks.com.gh/stuart-seldowitz/

Stuart Seldowitz was former Director of the National Security Council under President Obama and former diplomat for the U.S. State Department serving during five presidencies.

The latter seems to suggest he was career diplomat which appears more likely given his own auto-biography.

What job did he have in the Obama administration though? That's not at all clear from his own brief auto-bio, which doesn't seem to verify anything related to the National Security Council, which is distinct from the State Department.

There's a related Q here about some other past job claims about him, but there's also, e.g. in the Daily Mail:

Barack Obama's former director of the National Security Council has been unmasked as a man seen unleashing an Islamophobic attack on a street vendor.

It's then partially repeated that

Seldowitz [...] worked in the Obama administration.

Or https://www.ghlinks.com.gh/stuart-seldowitz/

Stuart Seldowitz was former Director of the National Security Council under President Obama and former diplomat for the U.S. State Department serving during five presidencies.

The latter seems to suggest he was [also] a career diplomat which appears more likely given his own auto-biography, in which e.g. says he won State Department’s Superior Honor Award three times.

What job did he have in the Obama administration though? That's not at all clear from his own brief auto-bio (linked above), which doesn't seem to verify anything related to the National Security Council, which is distinct from the State Department.