Getting data via API or uploading data?

Question

API

We are planning a new online store website. There is a CRM that stores goods, deals, etc. We can do both uploading from CRM to the site and receiving all the necessary data via the API in real time, while not storing them on the site. The essence of the question: what is better if you get data via the API in real time or write data upload to the site? What are the pros and cons of these approaches? 

P.S. I thought about this question, but I did not manage to collect enough information to make a choice, maybe someone had experience and can share advice.

Answer 1

Find out what is "better" from the one who uses this data, whether he needs real-time or enough unloading on demand.

Answer 2

is your crm ready for the load that the website will generate?
if you upload data, then you will have to monitor their relevance
. uploaded data is a cache of original data, in principle, you can combine the approach, work with api but provide a mechanism for storing (including preloaded) copies of data in the web server database, adding api crm tools for notifying about changes and updating this data.
ps I like the options for building on the basis of master-slave replication of the crm database using sql databases, all changes will be quickly (with a very minimal lag) uploaded to the slave-replica of the database, and now the web server can easily work with it as with its own, on reading