A friendly chat with an Architect and then with the Core team about the technologies used and stuff (very nice people, a positive experience) with some key questions to see if I mastered some tools.
Got in touch with the HR manager and received an offer; she wanted an unconditional OK in three days before even sending the contract draft or the company policies (important things to know about - on-call, working equipment, etc.). Told her I couldn't jump in point-blank without knowing the details of the agreement and they withdrew the offer.
Unfortunately, this company lives up to the reputation it has on Glassdoor - lots and lots of red flags. It's a shame since it looks like it has many bright people on its technical staff.