Technical leadership lacks the technical background and experience necessary to adequately direct research, new technology development or to solve problems that inevitably pop up when changes are made to the existing product. This is especially problematic because technical leadership insists on a very top-down, autocratic management style despite hiring (for the most part) very talented and capable PhD level engineers and scientist. The result is a pseudo-intellectual, bully culture where experimental evidence is only relevant if it makes (middle-)management look good. While I was at Dexcom it wasn't uncommon to see people with PhD's blatantly manipulate or misrepresent data to please (or avoid the wrath of?) their vindictive supervisor. I also saw people present thorough, honest data that refuted the leadership's latest hair-brained hypothesis and where then transferred to a different project or quietly uninvited from the weekly project meeting.
None of this should really comes as a surprise though, when you consider that none of the founding scientists or engineers are still at the company and that the current CTO (who holds only a bachelors degree in electrical engineering) just happens to be married to the former CEO's daughter. And it's all unqualified legacy employees from there on down.
It's almost impressive how bad working at Dexcom is. Unless you're some kind of glutton for punishment I'd seriously consider looking somewhere else. Or don't believe me and you can experience it for yourself.