Aaron Pfeifer
Senior Principal Software Engineer at Tapjoy
Winston-Salem, North Carolina, United States
Summary
👤
Senior🎓
Top SchoolAaron Pfeifer is a Senior Principal Software Engineer with 19 years of experience building scalable web architectures and leading engineering initiatives from Winston-Salem, NC. He combines hands-on backend craftsmanship in Ruby and Rails with strategic architecture direction—recently driving GraphQL reporting APIs, a migration to MemSQL, and a unified data lake at Tapjoy. A dedicated mentor and organizer, he leads working groups and product/tech review processes to raise organizational quality while still contributing core code. His open-source contributions to prominent Ruby projects like graphql-ruby and fakeredis show deep familiarity with testing, state machines, and API design. Comfortable operating across systems from Chef and AWS to Scala services, he seeks environments that foster continuous learning and strong engineering culture. Colleagues rely on him for pragmatic, maintainable solutions that scale and for developing the next generation of engineers.
19 years of coding experience
Bachelor of Science in Engineering, Bachelor of Science in Engineering at Rochester Institute of Technology
Stackoverflow
26reputation
2kreached
1answer
0questions
Github Skills (21)
lib10
redis10
api-design10
testing10
schema-design10
object-oriented-programming10
wpgraphql10
ruby10
state-machine10
wordpress-graphql10
graphql10
graphql-ruby10
refactoring10
data-structure9
data-structures9
Programming languages (9)
Github contributions (5)
pluginaweek/state_machine
Oct 2006 - May 2013
Adds support for creating state machines for attributes on any Ruby class
Role in this project:
Back-end Developer
Back-end DeveloperContributions:719 commits in 6 years 7 months
Contributions summary:Aaron primarily focused on modifying and improving the core functionality of the `state_machine` library. Their work involved refactoring code to support gem-compatibility, removing outdated code, fixing issues with class inheritance and event handling. These changes included modifying the core library files to improve their structure and fix several bugs related to transition arguments and class inheritances.
rubystate-machine
guilleiguaran/fakeredis
Jul 2011 - Jan 2012
In-memory driver for redis-rb, useful for development and test environments
Role in this project:Back-end Developer
Back-end DeveloperContributions:8 commits in 5 months
Contributions summary:Aaron primarily focused on implementing an in-memory driver for the `fakeredis` project, acting as a mock Redis server for testing purposes. They added a `Memory` connection class, implemented various Redis commands like `get`, `set`, `del`, and others, mirroring the functionality of a real Redis instance. Their work included handling data storage within the in-memory driver, managing expiration times, and ensuring the correct behavior of Redis operations within the mocked environment. This development was then tested by ensuring that various tests were passing after the implementation of the `Memory` connection class.
driverredis
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