At first I applied via job board, then recruiter screening, one week leater System design interview and Coding interview. I get declined at this step with quiet big feedback. All take around 3 weeks. And meeting in summarize was 4 hours.

Straightforward. They're looking for your approach towards a problem and how efficient your solution is, they don't care about any coding syntax hiccups. There were multiple questions (not all LC) - Unix Commands - Identify Synchronization Issue in the given code - Find K Most Frequent words across all files in a given dir path - Flip Kth Bit