How can I improve my chances of being hired at Infoblox?

Regardless of what project you're working on, showing you understand how DNS works - even if you never need to code for it - shows you're "on board" with the company's core product. Demonstrate your Python knowledge. It's used a lot, and they like that. Get good with AWS/Cloud tech - they're trying very hard to move into the cloud space and any experience - real or apparent - will help you stand out. Any security experience - even if just doing "more secure" coding - will also help. They are trying so hard (and mostly failing) at becoming a security player. Having that on your resume won't hurt a bit.