Acid's a solved problem; PTFE (Teflon) is a comprehensive solution to hot sulfuric acid, well validated in chemical engineering problems on Earth. It's versatile enough you can even coat balloons with it [0].
The hard part is keeping electronics cool. The balloon ideas offer a really elegant solution. You could cycle a balloon between altitudes—between the 500 °C surface, and cold layers of the high atmosphere, cooling off and refilling a thermal storage reservoir for the surface. On Venus, can find cool 20 °C air at a very reasonable, balloon-navigable, 0.5 bar pressure level [1].
The hard part is keeping electronics cool. The balloon ideas offer a really elegant solution. You could cycle a balloon between altitudes—between the 500 °C surface, and cold layers of the high atmosphere, cooling off and refilling a thermal storage reservoir for the surface. On Venus, can find cool 20 °C air at a very reasonable, balloon-navigable, 0.5 bar pressure level [1].
[0] https://robotics.jpl.nasa.gov/news/up-up-and-away-to-venus/
[1] https://en.wikipedia.org/wiki/Atmosphere_of_Venus?#/media/Fi...