I’ve developed a few Qlik apps. Probably the single greatest help I have had along the way has been the ability to turn to the knowledge base of others. Working at Qlik, I am lucky that I can turn to developers near me as I look for answers on how to do something - I turn to my local community. Clearly not everyone has this luxury. I strongly encourage you to utilize one of the online Qlik Communities. Qlik Community, this Qlik Blog and Qlik Branch all offer different kinds of knowledge from industry trends, best practices and actual code to help solve your problems. Learn from others but also get involved and use your knowledge to help others learn. Use your knowledge to help the people behind you avoid making the mistakes just as others further ahead will invariably help you.
Communities of learning are some of the best resources the internet has produced. Get involved, get active, help others and produce better Qlik apps along the way.