Web conference call with 4 other people (during depths of coronavirus pandemic, so your mileage may vary). They asked questions about my knowledge and how I might find what they found.
Their questions weren't difficult, it was how they phrased them that made me think that they were more interested in telling me how awesome they think they were. Seeing one interviewer later at a security conference confirmed that suspicion.
They wanted a very particular skillset for which they were not paying the market rate. They wanted to undercut my current employer for the privilege of working for them.