Do not take external money. The longer you can bootstrap the better. I know you've heard this a bajillion times, and I know the allure of a few mil in the bank

Do not take external money. The longer you can bootstrap the better. I know you've heard this a bajillion times, and I know the allure of a few mil in the bank. It's not worth it. Hold off as long as you possibly can. We've used Google's AppEngine to scale. It's not the easiest env to work with, but at 30+ staff and millions in revenue we have yet to hire a sysadmin (ie. overhead!). When load increases we just get charged for more resources. Sounds like you have to parallelize: start MVP rebuild, and do mitigation on current platform. Four years in we are on the fifth major rev of our core processing system; point being that things change and you need to prepare for ongoing evolution.