As mentioned, we will be building a travel marketplace. It will connect the customers and the sellers. Both parties have varying requirements from the platform, and the marketplace needs to ensure that both are reasonably satisfied. This diagram describes the product at a high level:

Let's look at the following points for more clarification between customers and sellers:

• Customers should be able to search for hotels and flights. Key functional requirements include the following: 
  • The ability to show results from various sellers' sources.
  • Price consistency: Show prices that are close to what the customer would finally pay.
  • The ability to see discounts and promotions.

• Customers should be able to see personalized prices on the search results screen. These are essentially markdowns on the standard prices, and the discount is derived from a loyalty points-based rewards program. For example, if a hotel reservation is priced at $500, and if the customer's wallet has $100, then the price shown should be $400.
• Customers should be able to book hotels and flights. This involves handling payments and confirmation from the seller.
• Customers should be able to manage their booking, including cancellations.
• We should be able to onboard sellers quickly to the platform. It can be assumed that they give well-defined APIs for searching and booking.
• Customers should get an email invoice once they buy something.
• Customers should get an email if something goes wrong during booking.
• The search on the website needs to be fast. Customers should be able to see initial results within one second.
• Customers should be able to see prices that are close to what they would finally pay. This means we can't just cache data forever.
• Sellers do not offer high Service-Level Agreements (SLAs) to us, since we are just a fledgling startup. They do however offer good commissions.
• Sellers have a look-to-book ratio. They charge us if we do too many searches for too few bookings.