I looked over the site, but would rather get these questions answered by an actual developer since anything you say is going to likely be way more accurate than anything placed on the company's site.

• What's the salary range?
• If you start a KC based team, is work from home a possibility, or would it require working from an office?
• What's the preferred or most often used stack? I know you said multiple, are there any languages that tend to be favored for specific tasks?
• How large are the teams generally? What processes or tools are used to ensure effective communication among team members?
• How are new requests / bugs handled? Is there a centralized issue tracker (JIRA, Redmine, etc) or does it vary? If all issues don't go through a tracker, how often does it deviate?
• What VCS is used? Git, SVN, Mercurial?
• How are deployments / updates handled? Is there a dedicated team that handles deployments, or is this left to developers?
• What does the org structure look like? Who do developers report to? Who does that person report to?
• If and when there is a disagreement among developers, how is that handled?
• How much creative freedom are developers given? Who has the final say?
• Can you give an idea of the company's success? What were the revenue numbers from last year. What are the projected numbers for this year?
• How much importance is placed on best practices? Good architecture? What about TDD?
• How often do you work on multiple projects at once? Are they truly different projects, or are they just multiple deployments of the same product with customizations per client?
• Is there a dedicated QA team, or is this left to developers themselves?
• Is there a defined testing process? Does it include Unit tests, Integration tests, etc?
• What does the company consider a "full stack" developer? Do developers get asked to double as sys admins, tech support, etc?

I could probably think of at least 20 more questions, but don't want to overwhelm you right off the bat. :)