Many large engineering organizations have internal document collections that detail past research and lessons learned. Google may be the most visible engineering organization, but many quiet financial and defense-oriented organizations have a wealth of information available, once you are inside. This info is commonly very specialized, so it would be unlikely to help you build the most scalable website or awesome mobile app, but might be useful in creating a toaster-oven that can survive a 100ft drop, being run over by a tank and lasting for 200 years.

Any engineering firm can develop a world-class knowledge base. But, that involves an engineering process, like starting projects with statements of work and conducting internal engineering reviews at certain milestones (all documented in whitepapers), not just by creating a Trello card or JIRA issue.