CPKC interview questions

I applied through an agent and had two rounds of interviews. Unlike the normal interview processes I had had before, I was interviewed firstly by the hiring managers and his supervisor and key partners. It went pretty well and I could feel a lot of sparks. Just a few hours later I was invited to another round of interview with the "peers", which ended up a tricky experience. There was a panel of four people from a variety of technical backgrounds, which was just normal. But to my surprise, they asked a very wide range of questions, from database schema design, DB performance tuning, Dimensional Modelling, Log-based database replication, Dashboards design, to data mining models. They even asked me to explain how to create a predictive model using the data provided in the meeting. I was actually glad to be able to address all the questions thanks to my solid background and experiences in BI and DM areas. Only after finished the interview I realised it's not a usual case for a "data specialist" role. Seriously, it's intense enough for a full stack data scientist/ data engineer. Isn't it? A week after I heard from the agent that I was not offered, which was a bit disappointing but not too bad. But guess what, the reason they claimed is "inability to communicate with the team". Seriously? The candidate could have a great conversation with the bosses but was unable to communicate with the staffs? A candidate who had been working as a professional in the area for 10+ years? PS, one of the "peer" who interviewed me was just promoted as the head of the dept. Nice job. Congrats and good luck.