Pros: Optiver is not a good place to work. Its culture is too toxic. I cannot say any pros, except its payment is higher than most IT companies, which you exchange for both your mental and physical health.

Cons: Culture is toxic. Worse and worse work-life balance in the Shanghai office. No career development. Most IT managers are incapable; they just keep pushing.

Pros: Good food and large bonuses

Cons: Extremely political. The majority of where you must spend your time to survive at Optiver is politics. If you do not, you will be eaten by others that do. Management has zero interest in dissuading this behavior. Watch your commits, as large pieces of work will be quietly re-based into other developers' names. This is not by accident, as you'll start hearing word back that they're bragging about having written the code. Poor management promotes the worst people to management roles after seeing their own negative traits in them. Management is also gifted to long-term employees who cannot keep up with the technical work anymore. These managers all review each other, ensuring the quality stays low, as poor management has the majority and removes anyone that doesn't have the negative traits they hold up as ideal.

Pros: The environment is friendly, and the people working there are great, both professionally and personally. The company realized it has a lot of technical debt and is investing heavily in reducing it. It's trying to become a world-class software development firm.

Cons: For most of the lifetime of the company, getting things done in a hacky way has been acceptable. This shows in the state of the codebase, which could be less than pleasant to work with.