Justin Spahr-summers
Director at Fern Forest Games
London, England, United Kingdom
Summary
🤩
RockstarJustin Spahr-Summers is a seasoned software engineer and director with 15 years of experience building production-grade systems and leading teams across AI, mobile, and developer tooling. Based in London, he has combined hands-on engineering at companies like GitHub, Facebook, and Anthropic with leadership roles that span IC deep work and team-building—most recently directing an AI-driven games company. A prolific open-source contributor, his work touches tooling and infrastructure projects from libgit2 and Carthage to React Native and the Anthropic TypeScript SDK, often improving robustness and developer experience. He moves comfortably between back-end, DevOps, and mobile iOS code, with notable contributions to CI integrations, SDKs, and testing frameworks. Colleagues rely on him for technical mentorship and pragmatic architecture, and he has a track record of turning research-grade ideas (reactive/live queries, agent simulations) into production-capable systems.
15 years of coding experience
15 years of employment as a software developer
Stackoverflow
16,933reputation
978kreached
185answers
0questions
uibutton
top-5%
iphone
top-1%
cocoa-touch
top-5%
cocoa
top-1%
macos
top-5%
ipad
top-5%
Github Skills (93)
atom-editor10
dependency-management10
json-parser10
mobile-development10
python10
multithreading10
ui-components10
api-client10
testing10
authentication10
c1110
cocoa10
ruby10
c1710
vim10
Programming languages (20)
Github contributions (5)
octokit/octokit.objc
Jan 2013 - Mar 2015
GitHub API client for Objective-C
Role in this project:
Back-end Developer
Back-end DeveloperContributions:1 release, 546 commits, 12 PRs in 2 years 2 months
Contributions summary:Justin's primary contribution appears to be the development of the OctoKit Objective-C library, as shown by the initial code commit introducing the core client and data models, and numerous commits focused on building the API client and related data structures. This included adding models, implementing API requests for fetching data such as user information, repositories, and gists, and handling authentication. Subsequent commits focused on refining the library with better pagination and adding additional functionality.
api-clientobjective-capiios
modelcontextprotocol/servers
Nov 2024 - Mar 2025
Model Context Protocol Servers
Role in this project:Back-end Developer
Back-end DeveloperContributions:1 release, 237 reviews, 139 PRs in 3 months
Contributions summary:Justin implemented a Slack server within the Model Context Protocol (MCP) framework. They defined various tools for interacting with Slack, including functions to list channels, post messages, and manage threads. The code involved integrating with the Slack API using a client library, enabling communication and data retrieval from Slack channels. The changes indicate the development of a server to facilitate interaction with Slack using the MCP.
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