I was at first screened by recruiter from Brno facility in Czech language. That took around 30-mins. They I attended the next round of interview with manager of kernel team based in California. It took around 1.5 hours. After 2 weeks of silence I've got a call from recruiter if I know some candidate suitable for the management position of the newly established kernel team in Brno. Afterwards, I haven't heard back from them. Simply ghosted me and recruiter tried to get some referrals from me for free. Ghosting is unprofessional and asking for free referral is even inappropriate behaviour to me.