You should keep the following aspects in order to find the best suitable Travel Portal Development Company for all your requirements.

  1. The portfolio is the best page where you can find the best job done previously from respective vendors.
  2. API Server Uptime
  3. Content is the key. Not for the search engines for sure, as these will all be duplicate contents but Yes for the customers. More content they find, fewer chances they visit other sites for other information.
  4. Customers feedback page – Just to learn how the company performs after sales.
  5. How customizable their solution is.
  6. Customer Support availability
  7. How social and Transparent they are
  8. Personal attention they give

Though it’s not limited to the above points, you should dig more and find if the customer is suitable for your Project.