You have to admit that it’s nicely vague. So what exactly does it involve?
If one had to define “working in policy”, it would be as a fusion of research, consulting and advice, often morphing into something dangerously adjacent to PR. Policy advisers provide the foundations and structure for decisions that are high- level and far reaching.
No 1 employer of policy advisers is Her Majesty’s government in its central, devolved and local incarnations (and – until spring 2019 at least – at European level too. Post Brexit? Your guess is as good as mine). Your overarching role in this context would be to provide objective advice, based on fact. Key functions here would be to analyse data, brief and debrief ministers (they’re not the experts here – you are), and answer questions posed by other politicians, the press, the public.
As a British Prime Minister once (allegedly) said, “A week is a long time in politics”. Things change fast, very fast. So if a political crisis brews up (and don’t they always with alarming regularity?) you’d need to be as nimble and nifty as any gymnast in grasping the implications, handling the fallout and adapting your strategy.