Pros
You will be forced to touch every single part of the stack—front-end, back-end, middleware, database, and networking—because the company relies on individuals to carry the weight of their technical debt.
Kontras
If you are offered a position here, run. Management completely lacks an understanding of modern software development. Engineers are held to unrealistic, poorly communicated timelines, and the technical direction is purely subjective rather than data-driven. The biggest issue is that "management" consists of senior developers who have been handed managerial titles with zero leadership training. If you work hard to modernize their stack (implementing mutual TLS, automated testing with Pytest, building RESTful APIs, and revamping legacy UIs), do not expect it to be appreciated. They will gladly take advantage of your work ethic to build out their core requirements, only to throw you away and find any excuse to get rid of you when you are no longer needed just to save a few dollars. It is an incredibly unappreciative environment with horrible company ethics.