I've seen other people take a bunch of open source components - not knowing in depth how they worked - and put them together to create surprisingly credible sol

I've seen other people take a bunch of open source components - not knowing in depth how they worked - and put them together to create surprisingly credible solutions very cheaply, the kinds of solutions that win 7-figure SaaS deals. You don't get there with your knowledge of binary trees or compiler principles. But having some basic algorithms knowledge might make the difference between delivering such a solution that runs reliably and quickly enough and not.