> At EuroPython last year, I gave a talk on why tools like Django and Ruby on Rails are great for building simple projects, but terrible to scale. The problem is that they help engineers build a system fast, but put huge obstacles to changing the way to store data.<p>Applications have to get truly massive to run out of scale with that architecture.<p>Using the largest instance on EC2 with the largest RDS configuration will comfortably scale to millions of DAUs for almost every CRUD app.<p>As a solo dev, founder, or early engineer at a company, worrying about outgrowing these is like worrying about how you'll cater for a 1000 employees at off site events.<p>Even in large companies, very few apps will reach a scale beyond what Django/rails can accommodate.