How plausible do the 5 star positive reviews look to you?
Pros
In theory the product should be useful: public transport is great right? Its a little bit more complicated, Cityswift works mostly for private bus companies where its all about profit. Flexible work arrangements, including remote, but they expect you to work very hard (and the inner circle frequently brag about working terribly long hours and at weekends: expect this to be expected of you). Nice colleagues outside the inner circle. Tech for good? Debatable: what's the carbon footprint of all this expensive cloud computing? How many fewer car journeys happened because of the buses? How much happier are customers with the service? Who knows, its possible, but not obvious.
Cons
Management: inexperienced in the worst way from the top down. The two founders have very little experience and have surrounded themselves with a clique who want to manage the employees with an iron fist. Lots of unfair reviews, micro-management (about things they don't understand), bad language and a lad's culture. Junior (but talented) engineers are being taken advantage of. Financial shenanigans. Startups are all about marketing, mostly to prospective employees. The work is not more interesting than at every other company but the stress will permeate you and you won't realise it: it will seem like the important thing in the world but it isn't in the slightest. Your sole purpose is making money for the investors and the founders at any cost to your own health. There is currently a bubble in startups for a few reasons. Among them, interests rate are so low than investors are piling money in to startups as a risky investment that might pay off. What happens when interests rates increase as they probably will and investors have to pile money into unprofitable ideas to keep them afloat? If you're applying for a job, ask about the numbers and do your own sums about whether they add up. Whatever every about the global financial situation, if they are offering you equity and claim it'll be worth X in a few years, ask yourself how likely that is and how likely it is that they will be be bought go public: most startups come to nought. Did I mention management?