Once I get a job offer, I can apply for the work VISA and can work.
These two statements don't mix very well with the current EU employment law.
The employer will have to prove that they cannot find a suitable candidate within the EU before you're issued with work permit.
I honestly don't know where you should start, i think this route is highly unlikely to get you a) a job & b) a work permit.
Two possible options;
1. Enroll into a University and do a Polish based IT degere/Diploma. It's easier to get a student visa than a work permit. I think if you stay in Poland for a certain period, then you might be eligible for a residence permit. Ask some lads on here, they know better than i do.
2. Start a small scale software house company. If your financial expertise is solid as indicated, you should be able implement high end application products (both front end and back end). The major problem here is you'll need thorough knowledge of the Polish financial industry. It's a regulated industry hence you need to be upto scratch with industry procedures and i've not mentioned the language barrier yet.
Jro, i'm a very optimistic fella however, my optimism is really wearing thin here.
Your biggest problem is the work permit. if you can find another way to acquire residence (temporary/permanent) in Poland then you could stand a chance employment wise.