Is it permissible to continue working for a foreign company characterized by tabarruj (improper display of adornment by women) and ikhtilat (free mixing of sexes), that forces the employee into khalwa (private seclusion) with his female manager, prohibits Islamic dress, and deals with a Riba-based (usurious) bank, especially given that the company belongs to a country that has insulted the Prophet, peace and blessings be upon him? And is it obligatory to leave this job when a financially viable alternative becomes available?

Your presence in a country where evil acts are prevalent does not make you accountable as long as you detest them. You must denounce them to the best of your ability.

Your work in the company must comply with Sharia (definition) regulations. Seclusion (khalwa (definition)) is not permissible, and you must lower your gaze. If engaging in forbidden acts is inherent to the work, then it is not permissible for you to continue in it except in cases of extreme necessity, and in such cases, necessity is estimated by its extent.

You are not required to wear a thobe at work or outside of it. Rather, wear what is suitable for your work, as long as it does not expose your awrah (private parts).

You are not held accountable for your salary being deposited into an usurious bank if you have no means to avoid it.