Justin Rahardjo
Freelance Software Developer at Self-employed
Kaslo, British Columbia, Canada
Summary
👤
Senior🎓
Top SchoolJustin Rahardjo is a versatile full-stack software developer and former CTO with 12 years of experience building AWS-backed serverless systems and React/TypeScript applications across healthcare, workforce mobility, and real estate domains. Now freelancing from Kaslo, BC, he blends product-minded engineering with hands-on implementation—architecting backends, shipping web and mobile clients, and improving build pipelines. He contributes to open-source projects including langchainjs and a lightweight Node.js CMS, demonstrating attention to build tooling, parsing robustness, and MapReduce-style chains for LLM workflows. Equally comfortable leading technical teams or diving into code, he pairs a mechatronics engineering background with a curiosity for AI/ML and a streak of entrepreneurial experimentation (currently pursuing a 12-startups-in-12-months challenge).
12 years of coding experience
9 years of employment as a software developer
Mechatronics/Commerce, Engineering and Commerce, 5.602, Mechatronics/Commerce, Engineering and Commerce, 5.602 at The University of QueenslandHigh School, OP 2, High School, OP 2 at Marist College Ashgrove
English, Indonesian, French
Stackoverflow
166reputation
19kreached
4answers
6questions
Github Skills (28)
javascript10
langchain10
zod10
gulp10
typescript10
build-automation10
typescript-types10
nodejs10
typescripts10
css9
lessc9
babeljs8
babel68
apidoc8
api8
Programming languages (12)
Github contributions (5)
Gottwik/Enduro
Apr 2017 - Jul 2017
Minimalistic, lean & mean, node.js cms
Role in this project:
Full-stack Developer
Full-stack DeveloperContributions:15 commits, 5 PRs, 13 comments in 3 months
Contributions summary:Justin primarily focused on updating the build process and configuration of the node.js CMS. They made changes to the gulpfile, server configuration, and various build tools to ensure the correct handling of assets such as CSS, Javascript, and images. Additionally, the user implemented features for less/css handling and babel transpilation to enhance the build and development workflow. Furthermore, several changes were done to modify temporary page generation, file paths and server routing.
cmsnode-jsnodejsminimalisticlean
langchain-ai/langchainjs
Apr 2023 - Nov 2023
🦜🔗 Build context-aware reasoning applications 🦜🔗
Role in this project:Back-end Developer
Back-end DeveloperContributions:2 reviews, 6 PRs, 11 comments in 7 months
Contributions summary:Justin primarily contributed to the improvement and refactoring of code related to the `langchainjs` library. This included fixing bugs related to output parsing with Zod and removing unnecessary code. The user also added functionality to a `MapReduceChain` and made updates to the codebase that improved its efficiency and maintainability. Additionally, the user made some documentation updates.
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