Data mining and web crawling to find websites and best selling products

I am searching for somebody who has experience with data crawling in the web. You should also know the shop system by Shopify. The project includes the following tasks: 1) Collect all URLs from active stores in the Internet which are using the Shopify shop system. There are more than 250.000 store to collect. 2) Insert this data in a database (MongoDB prefered) and rank it by traffic. Therefor you need to find out how high the traffic (visits) per month is. 3) Let the crawler open the page with the best selling products and save the 5 best selling products for each store in the database as well. For each product we need to save the following information: - product name - product price - product image The crawler and all other written code should be copied to our repository after the project is done so that we can run the crawler later again. The database should be hosted on our infrastructure once the job is done. PLEASE ONLY APPLY FOR THIS JOB IF YOU ALREADY HAVE EXPERIENCE WITH SUCH JOBS AND IF YOU KNOW THE SHOPIFY SHOP SYSTEM.