Stuart Halloway
Northern Virginia Software Symposium
Reston · April 25 - 27, 2014

President of Cognitect
Stuart Halloway is a founder and President of Cognitect, Inc. (www.cognitect.com). He is a Clojure committer, and a developer of the Datomic database.
Stuart has spoken at a variety of industry events, including StrangeLoop, Clojure/conj, EuroClojure, ClojureWest, SpeakerConf, QCon, GOTO, OSCON, RailsConf, RubyConf, JavaOne, and NFJS.
Stuart has written a number of books and technical articles. Of these, he is most proud of Programming Clojure.
Learn more about Stu's presentations on his wiki.
Presentations
Narcissistic Design: 10 Steps to Complex Code and Job Security
The software industry changes rapidly, but you can protect yourself
from these changes by creating code that is complicated enough that
only you can maintain it.
Generative Testing
Traditional automated testing approches combine input generation, execution, output capture, and validation inside the bodies of single functions. Generative testing approaches gain expressive power by isolating these steps.
Simulation Testing with Simulant
Simulation allows a rigorous, scalable, and reproducible approach to testing. The separation of concerns, and the use of a versioned, time-aware database, give simulation great power. This talk will introduce simulation testing, walking through a complete example using Simulant, an open-source simulation library.
Clojure in 10 Big Ideas
The key to understanding Clojure is ideas, not language constructs.
In this talk, we will approach Clojure via 10 Big Ideas.
core.async
The goal of core.async is to decouple producers and consumers of
information in software, without dictating specific thread or blocking
semantics, and without introducing callback hell. Also, to do all of this
as a library, portable anywhere you can run a dialect of Clojure.
Queues are a powerful tool for decoupling software
programs. Unfortunately, platforms that have powerful queueing
libraries (e.g. Java) may require blocking threads on the ends of the
queue. And the world's biggest platform (JavaScript in the browser)
doesn't even have queues or threads.
core.async builds upon the work done with Communicating Sequential
Processes,
and provides:
- facilities for independent threads of activity, communicating via
queue-like channels - both real threads and shared use of thread
pools (in any combination), as well as ClojureScript on JS engines
Datomic For The 96 Percent
Traditional SQL databases have great power, via ACID transactions and
via a declarative, logic-based query language (SQL). But SQL
databases encounter two problems on the web:
SQL databases have a rigid information model, and typically a rigid
deployment model. This rigidity creates impedance mismatches both with
development languages and with emerging cloud strategies.SQL databases struggle with the extremely high write volumes that
characterize the top four percent of the web, e.g. the Amazons,
Facebooks, etc.
Much of the effort of the NoSQL movement has gone to solve the second
problem, the problem of the four percent, under the mantra “web scale”.
Datomic solves the first problem – with a flexible information model
and a deployment model suited to the dynamic web, and to the cloud.
Datomic is for the ninety-six percent.