Bloomberg LP

I've worked as a software engineer at Bloomberg for quite a few years now. While I've worked on a few difficult projects, I think they get a lot of things right:

• Engineering is treated as a profit centre; maintaining and enhancing the product are valued as core business activities
• Ongoing investment into developer experience and tooling
• Many smart and hardworking employees who take their jobs seriously
• As a mature and successful company, there is legacy code - but technical debt is taken seriously and there are initiatives that work to keep this under control
• The company ethos is positive: inclusive, collaborative, ambitious, and serious about providing a valuable product to customers

In London, Bloomberg asks for a 9-hour workday (10 including lunch). I haven't seen examples of this being monitored or enforced, but it's something a prospective employee should consider.