Apparently, the database design doesn't look to be complicated and any fresher from a decent college can do the job.

The challenge comes from the following situations:

• Your database is designed for today and not ready for new application features that you may need to tomorrow. Why is that important? Because if the database is not properly modelled, you may have to end up re-writing the entire application in future. Maintainbility of design is one of the most fundamental aspects of any application architecture.
• Your database is designed for data that you've today and not ready for the volume and velocity of data that you may need tomorrow. 95% of Software projects fail because it is not designed for scale. So when you design and develop an application with a database design that easily supports 1000-2000 customers, you do the testing and you're happy. But tomorrow, your customer-base grows and you now have 10000 concurrent customers and your entire database slows down like hell just because your database is not performing.
• You've designed the database designed in such a way so that it is vendor-locked! You may have to end up churning out a huge amount of money to redevelop your application in parts or in full just because you want to move away from one playform, say, Microsoft SQL Server, to, say, Postgresql.
• The business logic of your application is intricately woven inside your database! Nothing can be worse than that as your application seriously risks all important quality needs: maintainability, scalability, performance and security.

I've over 30+ years of experience in architecting and developing serious, highly-scalable, mission-critical applications - both on the code/backend side as well as database design. I can design a super-performing, maintainable, future-proof database for your application.