- Overall its a clean website, not too much info about whatever one doesn't care about.
- The header BG isn't wrong, but the green > blue gradient doesn't feel 'right' to me (not a strong feeling and note that I'm no designer)
- Some elements (twitter icon / two signup buttons) are a bit off the overall flat style of the site.
- In my eyes (again, no designer), the 'want to teach' button also falls a bit outside the style with the darker color
- I'd make it clearer that the categories / course types are actually courses that will be available later on, right now its just a list of programming jargon that doesn't say anything.
- Also, there's a on-hover element, but no link behind it
- The spacing under the last signup form is a bit big
- Maybe make the secondary heading 1.5/2 times bigger..?
Hope that gives some useful feedback, I know the difficulty of creating a landingspage..
Jeroen Sormani