Lack of strategy and top management experience. Organizational structure and processes often change. Teams become reformed before they reach peak performance. Limited understanding of talents retention value, except in the risk of immediate damage. Reactive attitude to changes on the job market. The environment is tough and hectic for founders direct subordinates.
Startup mentality. Founders try to accelerate hiring and product plans, even they realistically can not handle headcount and ongoing operations.
Tech debt. Management is often not willing to pay off tech debt. Tech improvements are implemented irregularly and top engineering resources are wasted to pay tech debt interest, resolving system instabilities, fixing of reoccurring issues. Engineers end up rewriting different parts of the system from time to time, rather than keeping existing parts in a good shape.
No paid leaves during the first year.