Judging by the video's contents, he's worked on more than just missiles.
I'm not trying to absolve Uber or something, for the record: the people who work for Uber aren't innocent, either. It just seems clear that they're a lesser evil. Malpractice versus malfeasance.
Consider that the US military, particularly the Navy, with its missiles, has facilitated safe global trade since the end of WWII. That in turn has lifted more people out of poverty than any previous single measure in human history. The US Navy has done more good than Uber could ever hope to achieve.
On the other side, consider for instance what Iran and Saudi Arabia would start doing to each other if the recently energy-independent US disengaged completely from the middle east. You can look at Syria in the wake of Trump's withdrawal for a tiny sample of the kind of violence that would occur in such a power vacuum.
Now none of that erases the various abuses and misadventures of the US military, but you're reducing a highly complex equation stretching over 70 years to a single simple variable: "Do the machines kill people or not?"
If every engineer in the US simply refused to build missiles as it appears you desire, the second, third and fourth order effects of that choice might kill even more people than if the missiles had just been built and potentially used. I'd argue it isn't clear at all whether Uber or the US defense industry is the lesser evil, and in fact there's a lot more history to take pride in in the defense industry.
