[olliemath]

We use pypy pretty extensively at our firm for analytics/olap work.

We've actually tried using some of the more traditional libs (Pandas et al) with CPython, but there's always a pure-python bottleneck (e.g. SQLAlchemy).

Performance is important to our clients and trying to keep everything performance critical in C extensions / NumPy would be kind of risky for us when adding new functionality, so pypy's guarantee of more speed pretty much across the board is awesome.

There are downsides of course - higher memory usage, longer boot times, some more obscure libraries being unsupported - but on the whole, it's a good choice for us