Performance in the opposite direction is also useful;
the Ryū algorithm[0] is a fast float-to-string conversion that I've used recently to great effect[1]. Namely, to convert path information from glyphs into vector graphics for a minimal math-oriented Java-based TeX implementation[2]. The result is code that converts 1,000 simple formulas as strings into individual SVG documents in under 600 milliseconds on newish hardware.
[0]: https://github.com/ulfjack/ryu/blob/master/README.md
[1]: https://news.ycombinator.com/item?id=17633182
[2]: https://github.com/DaveJarvis/JMathTeX/blob/master/README.md