It depends where you draw the line in the tech stack. On the hardware side they've always worked at least at the same hardware level as any workstation or PC vendor, and often arguably lower than that working with component manufacturers to custom spec particular components.
They're an aggressive early adopter of new tech, putting in the work to adapt it to their product categories, sometimes directly funding tech development with partners to make that happen. They jumped on the tech for laser cutting aluminium laptop and mobile device bodies from aluminium blocks, gorilla glass for mobile devices, helped develop the specs and tech for retina and 5K displays, were actively involved in the development of open technologies like Wifi, USB, Firewire, etc. They've never been content to just buy parts off the shelf, pushing to promote the development of and get early access to new stuff other competitors didn't have.
On the software side they hired the best, including about half the former staff of Xerox PARC, the developer of the MACH microkernel, the developer of LLVM. You could argue that Apple didn't invent these technologies, but people at Apple did.