Pros
Great people and work culture. Generally young and relatively informal. Great work/life balance, especially for a start-up. Adapted well to rapid company growth. Very interesting and impactful work. Broad exposure to topics and projects. Somernova culture is pleasant with outdoor eating space, brewery next door, climbing gym few steps away, several restaurants, and a naturally-lit common space.
Cons
Development of technical skills was minimal. Cement chemistry is complicated and I didn't have the time and resources to understand it well enough to meaningfully participate in experiment design. Frequently changing environment as people moved to new projects or leave/join the company made it sad when someone you liked isn't there anymore. Clear career ladder and employee 401k matching need work.