I am always seeking a challenge with impact, so I have worn a couple different hats:

Programming Languages Researcher
I have done research in programming languages, especially applied type systems, along with some experiments in concurrency and mechanized metatheory. Please see my CV (pdf) for more info. You can also find a list of publications with download links here.
Cloud & Mobile
"Data" Engineer
I have built or contributed to the back-end of many companies, with a bit of a specialization in analytics/data concerns and a good amount of leadership experience. See my resume for more info. You can also see my open source contributions on github.

Here is a brief outline of some of my past endeavors. As mentioned above, I also maintain a resume (longer) and a CV(more formal).

Throughout 2013 I worked with Dimagi to improve data management capabilities in their flagship product CommCare, a suite of cloud and mobile technology supporting diverse efforts to deliver basic food, health, and education to underserved communities worldwide.
Data Viz
To contribute to my new locale of Boston and explore some interesting data, I joined a volunteer team building this interactive visualization of Hubway bike share data, which won Best Analysis.
In 2010 I joined Inkling to build their platform for building interactive learning content. I contributed to the development of nearly every piece of their backend. I quickly specialized and through 2012 directed their analytics team including business analysts, designers, front-end and back-end engineers.
In 2009 I joined an elite team of four developing iPhone apps for Fortune 500 brands including Gap, Timberline, Target and Cooks Illustrated, regularly featured in Apple commercials and stores.
Graduate Studies
From 2004 to 2009 I was at the University of California, Santa Cruz, doing research in programming languages, including that which led to my dissertation. All of my work from this period is available for download on my Publications & Projects page and summarized in my CV.
From 2000 to 2004 I led the development team building Cityspan's principle product, Youthservices.net, an information management system now used by over 100 large not-for-profit clients such as the Chicago Public Schools.

You may also enjoy my other quasi-pedagogical writings on mathematics, computer science, and technology.

Functional Lens
Casual essays (most of which are executable) about mathematics, computation, and functional programming.
Code // Comment
Tutorials (most of which are executable) about current programing technology.
In my dissertation, Executable Refinement Types, I present a new kind of undecidable type system that has the full expressive power of higher-order contracts. I demonstrate their formal semantics and explore how to perform type checking and type reconstruction, contributing new theory and implementation techniques for each, as well as novel architectural ideas for the compilation toolchain. My graduate work was advised by Cormac Flanagan. My dissertation committee also included Luca de Alfaro and Ranjit Jhala (UC San Diego).