Have already done automation of whatsapp. need to login once through web view scan and need to connect with mobile. Can provide you python script to scrape data from chat.
These are my skills related to web scraping and crawling
Have done scraping in CasperJS Phantomjs, python.
Have done testing and automation with selenium also.
Know to deal with database like mongo, mysql, Elasticsearch.
Also know to handle proxy and captcha while scrapping.
Can scrape data from various websites . have done scraping of millions of products from Amazon eBay Walmart. have done scraping of social media