Colin Mcdonnell
Founder at Pullfrog
Seattle, Washington, United States
Summary
🤩
Rockstar🎓
Top SchoolColin Mcdonnell is a founder and software engineer with 11 years of experience building developer-facing tools and open-source libraries from Seattle. He created and maintains Zod, a popular TypeScript-first schema validation library, and has contributed to high-profile projects like Bun and Gel, focusing on both core type/validation logic and improving developer experience through docs. Colin blends hands-on backend and full-stack engineering—shiping production React server changes and TypeScript typings—with a strong knack for clear technical writing and developer relations. He has repeatedly founded early-stage ventures and served in roles that bridge engineering, community, and product, including OSS Fellow at Clerk and Head of Developer Relations at Gel. Colin’s work shows an unusual combination of systems-level rigor (MIT EECS background and early research roles) and pragmatic documentation craft, evidenced by substantial documentation reorganizations and metric instrumentation guides. He describes his coding ethos lightheartedly—“here to chew bubblegum and write code”—but delivers disciplined, user-focused tooling.
11 years of coding experience
6 years of employment as a software developer
Bachelor's Degree Electrical Engineering and Computer Science, Bachelor's Degree Electrical Engineering and Computer Science at Massachusetts Institute of TechnologyLakenheath High School
Github Skills (24)
unit-testing10
type-inference10
schema-validation10
restructuredtext10
validations10
technical-writing10
typescript10
validation10
validating10
typescript-types10
typescripts10
validate10
documentation10
javascript9
edgedb9
Programming languages (12)
Github contributions (5)
colinhacks/zod
Mar 2020 - Sep 2022
TypeScript-first schema validation with static type inference
Role in this project:
Back-end Developer
Back-end DeveloperContributions:39 releases, 28 reviews, 124 commits in 2 years 6 months
Contributions summary:Colin's commits focus on adding functionality and fixing bugs within the `zod` library. The code changes involve modifications to the TypeScript types and validation logic of the library, specifically around set validation, size-related methods, and the creation of branded types. The user implemented new features for discriminated unions, and incorporated documentation updates, enhancing the library's functionality and user experience. The contributions demonstrate expertise in schema validation and type system implementation.
type-safetyzodvalidateruntime-validationvalidation
geldata/gel
Aug 2021 - Nov 2022
A graph-relational database with declarative schema, built-in migration system, and a next-generation query language
Role in this project:Technical Writer & Documentation Specialist
Technical Writer & Documentation SpecialistContributions:3 releases, 91 reviews, 70 commits in 1 year 3 months
Contributions summary:Colin's contributions primarily focused on improving the project's documentation. The commits involved correcting references, updating documentation to reflect changes in the beta3 release, and documenting Prometheus metrics, configuration parameters, and the new access policy features. Furthermore, the user reorganized the documentation structure, created new guides, and improved existing guides, demonstrating a commitment to enhancing the project's usability and knowledge base for users.
rdbmsedgedbgraph-relationalormrelational
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.