Justin Balthrop
CTO & Co-Founder at Medley Lane Studios
Los Angeles, California, United States
Summary
🤩
Rockstar🎓
Top SchoolJustin Balthrop is a seasoned technology leader and serial founder with 18 years of experience building product-led consumer and backend systems from Los Angeles. As CTO and co-founder across multiple startups—including a multi-year technical leadership role at Bird—he combines hands-on engineering (notably in JVM tooling and Clojure backends) with product strategy and scaling high-growth teams. He led backend architecture and services work at Geni that supported massive data and localization needs, and his contributions to open-source projects like Leiningen and a fast JVM launcher demonstrate deep expertise in developer tooling and runtime performance. Justin has shipped consumer hits (participating in products with tens of millions of installs) and repeatedly turned prototypes into products, blending design sensibility with pragmatic engineering. Currently founding and leading several ventures, he focuses on fast, efficient systems and developer experience improvements that often go unnoticed but materially speed engineering workflows. He holds MS and BS degrees in Computer Science from the University of New Mexico.
17 years of coding experience
16 years of employment as a software developer
M.S., Computer Science, M.S., Computer Science at The University of New Mexico
Stackoverflow
1reputation
0reached
0answers
0questions
Github Skills (16)
file-processing10
file-handling10
clojure10
javas10
management10
user-management10
user-profile10
file-access10
jvm10
fileio10
clojure-cli10
java10
build-automation9
performance-optimization9
bash8
Programming languages (13)
Github contributions (5)
ninjudd/drip
Aug 2012 - Nov 2017
Fast JVM launching without the hassle of persistent JVMs.
Role in this project:
Back-end Developer
Back-end DeveloperContributions:204 commits, 1 PR, 1 push in 5 years 3 months
Contributions summary:Justin primarily focused on developing a fast JVM launcher, implementing core features and addressing various functionalities. Their contributions included creating the basic launcher, integrating it with the Clojure REPL, and improving JVM pre-launching performance. They refactored the code to use delayed file streams for faster operation and implemented features like setting Java properties at runtime, indicating a focus on improving the tool's usability and efficiency. They also refactored the project to rename the project.
jvm-bytecodejava-bytecodejqkotlinjvm
technomancy/leiningen
Nov 2011 - Nov 2012
Moved to Codeberg; this is a convenience mirror
Role in this project:Back-end Developer
Back-end DeveloperContributions:58 commits in 1 year
Contributions summary:Justin contributed to the Leiningen core, focusing on enhancing its functionality and improving the developer experience. They implemented features like an `eval-in` multimethod, allowing code evaluation in different contexts, including a classloader. They also worked on project profile management by introducing composite profiles and reading profiles from a `profiles.clj` file, enabling greater flexibility in project configuration. Additionally, the user made improvements to the build process, notably printing specific commands to aid with testing.
convenience
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.