The article suggests playing around with a Raspberry Pi Pico, but this is a bit bare bones. Are there any kits, or entry level programmable drones on the market with a reasonable toolchain to program sequences?
https://www.bitcraze.io/products/crazyflie-2-1/
https://www.bitcraze.io/documentation/repository/
It was mentioned in this IEEE Spectrum article: https://spectrum.ieee.org/drone-quadrotor-2667196800
I have looked at the Ryze Tello [0] before, and it seems like a decent entry-level device, but I'm not sure whether it's actually a huge pain to develop for. I'd like something to be extendable _like_ a Pico, for instance if I want to install additional sensors, but all of these platforms are quite foreign to me.
Depending on what kind of drone you want to build (powered fixed wing, glider, quad, hex or octocopter) that might be more or less of an issue. Given the power draw and weight of an octocopter I don't think it would be much of an issue there but on a quadcopter, especially a very small one that might be prohibitive. But I'd focus on getting it to work before optimizing for size and weight.