Naming couple companies that you acquired for whom you changed the trajectory would be a lot stronger signal without revealing your identity.

On side note, its rare to see anyone fixing the old tech, its hard to fix, needs a different kind of talent thats hard to hire for the PE money. The folks who can understand some one else's decade old code and run their imagination through all the possible assumptions or trade off that might have been made in code/system are rare to find.

Finding new customers, finding more things to sell, finding synergies with other items in your portfolio, increasing the price for existing products are more realistic.