Bloomberg LP

If you have a good team and good work (which there is/are plenty of), then you'll love your time at Bloomberg.

Contributions to open source are allowed, and there are a number of internally developed technologies that have been open-sourced as well.

The company has a very social and open culture where talking with people is encouraged, and people are approachable at all levels and in all roles.

Bloomberg's size and problem space means that sometimes there are no open-source alternatives, or that it is necessary to drill down and improve an existing open-source solution. Smaller companies I worked for had to compromise, but Bloomberg is able to invest the time into creating great technologies if you can justify its need.

It's luck of the draw as to which team you will land in.

As a senior, you will directly be applying to a team, while as a junior developer, you will first be trained and then have a chance to apply to teams that are hiring.

Dealing with work that requires help from other teams runs into issues if that team does not have your work as a high priority on their side. This leads to frustrating workarounds or just project stalls altogether.

The social company culture can at times mean you get interrupted a lot by people asking for help with things you own, so be careful what you take ownership of.

More stability for the teams and fewer re-organizations would help us keep focus and get more done.