Have been working with different clients that comes to me to scrape sites using official APIs or extracting datas directly from HTML pages.
I can create programs that scrapes and crawls the web to find the specific datas using different libraries (BeautifulSoup, LXML, etc) or even just using plain Regular Expression scripts.
I've built them using different programming languages: Python, PHP, Visual Basic, JAVA, Ruby, and even just plain Javascript using jQuery or sometimes via a Chrome Extensions application.
The process I use are simple, I take into account when making the scripts to make it less prone to errors (if site's HTML changes), maintainable and it should run fast (asynchronously) by using a good library and good approach to tackling multi-pages.