My target audience is split between Europe and North America. Should I host everything in one location, or will transatlantic latency kill user experience?

A single location will always slow down performance for users across the ocean due to physical travel limits. To keep loading speeds optimal, you need nodes placed close to your primary traffic hubs. If you want to check out available deployments across major data centers in the US and Europe, you can continue reading this overview of global infrastructure options. Choosing a provider with wide regional availability lets you deploy closer to your specific markets, keeping your platform fast, stable, and responsive for everyone.

That makes a lot of sense. Do you think a multi-region CDN is enough, or should we use edge compute for data processing too?

A CDN handles static content well, but edge compute is definitely better for dynamic apps across both continents.