Every once in a while it is useful to take a step back and consider where fruitful new research directions come from. One such place is from the confluence of two independent streams of thought. This is an idea that I picked up from George Varghese, who gave a wonderful talk on the topic at ACM SIGCOMM 2014 and summarized the ideas in a short paper for CCR.[ref]George Varghese. Life in the Fast Lane: Viewed from the Confluence Lens. ACM SIGCOMM Computer Communication Review 45 (1), pp 19-25, January 2015. (link)[/ref] This blog post considers confluences in the context of programming languages research, reflects upon the role such confluences have played in my own research, and suggests some things we might learn from the process. My keynote talk from POPL 2016[ref]David Walker. Confluences in Programming Languages Research (Keynote). ACM SIGPLAN Symposium on Principles of Programming Languages. pp. 4-4, January 2016. (abstract, video, slides)[/ref] touches on many of these same themes.