The inside might not quite be what you are expecting. Hard working is not rewarding here, in most cases I know it rather quite punishing.
Try not to do anything that upset people that out rank you, instead try to provide them with the solution ready and demo as easy as it could be, the credit is their, but you'll be able to avoid pain in the future and hopefully switch team when you are too sick with the status quote of current team.
It's a mediocre nine to five job, don't bring your laptop home and do not work extra hours. After a few years I felt it was extremely unethical of me to encourage junior developers to contribute even if they love to, nothing good will come of it. Instead learning from the bad pattern here and invest best practice in your own project to prepare for your future job.
Performance review and pay rises are often incomprehensible. Due to the level of education, worthwhile contributions are ignored in favor of political goals in order to maintain benefits for certain people.