Pretty standard process starting with HR screener, followed by hiring manager and then co-founder, and other team members. One of the last rounds is meeting with a representative from the investor. The employees are kind and passionate about what they are doing.
They ask you to complete a short assignment prior to meeting the hiring manager.
The process is out of sync as they should have the investor do the screening as he has a large impact on the decision (FYI, he's unprofessional). The assignment should come after you have some exposure to the team / product.