A healthy mix is the only way to go! You get the benefit of spaces: that delicious feeling of control and power that comes with knowing that whoever looks at your code will see it just the same way you do, and second, you get the benefit of tabs: pressing the arrow keys less. You also get the additional satisfaction of knowing that whoever looks at your code is going to have to set their editor to use the same tab to space conversion that you do to avoid going crazy.

I'm pretty sure its much harder than rocket science. There's got to be a reason that SpaceX is valued around $50 billion (its still private) but Google has a market cap of over $1 trillion. It's not just the algorithm, but also the infrastructure, the databases, the crawlers, the indexers, the apis, the feedback metrics, etc.