After being approached by a recruiter I was scheduled an initial interview going over my background. I mentioned how though I have experience with C# though it's not very recent. After the interview which went well I received a technical exercise. The exercise was generally scoped well and could be completed quickly and had room to show your skills as a developer. I passed the assessment and went on to a technical interview with the initial interviewer and another employee from their London branch. All I was told is we were going to go over the exercise I submitted and having a technical discussion. During the interview I was asked some questions about my exercise solution, for reasons why I chose some specific implementations over others, as well as other deeper C# questions - which I personally didnt feel fully comfortable with (since as I mentioned my most recent experience hasnt been necessarily C# related). There was an additional system design part, which I wasnt told about ahead of time but still did well in even though they were looking for very specific answers (which seems counter intuitive for a system design interview). I asked the interviewers some questions about their experience with the company, what they enjoyed and they found interesting in their work - and the answers I got were only related to how hard they were working and how difficult some aspects are in their day to day which raised some red flags. After the interview ended I didnt hear from them for 2 weeks, after which the recruiter got back to me with the feedback that they werent going to proceed with my application due to my lack of in depth C# knowledge (which they were aware of from the get go).