There is a lot to learn and very little help or time to do so. Even when you feel like you're succeeding and moving at the speed of light management was displeased and will not pick performance issues instead of praising the growth and development. Performance improvement is a strategic way to remove you from the company. There is little I'm the way of patience in a startup like environment. While the company may seem large be warned you will wear many hats like a startup. In economic hard times the company would rather quietly eliminate employees than announce layoffs to save face to possible investors or buyers. This can mean last in and first out for your job.