For ATPG generation
Cadence: Encounter Test, now called Modus.
Synopsys: Tetramax
For most designs, DFT is fairly straightforward. Not sure why your company even needs a dedicated DFT engineer job. Analog, digital designers should already know how to implement DFT.
For digital DFT, just remember 2 keywords:
1. Controllability
2. Observability
Once these 2 concepts are understood, DFT is a piece of cake.