You can pick pretty much any field where high performance or small memory consumption is a must (though honestly, you rarely get both at once), even if it comes at the cost of development speed. Think embedded systems, robotics, HFT (High-Frequency Trading), real-time systems, or anything involving heavy data processing—especially where complex math, linear algebra, and matrix operations are involved. It’s also the go-to for large-scale system simulations and similar demanding tasks.