Sydney Runkle

Product @ LangChain

Somerville, Massachusetts, United States

About

Enhancing dev experience through open source tools built with Python and more. Currently working on DeepAgents, LangChain, and LangGraph, essential tools for Python devs using AI. Github profile: https://github.com/sydney-runkle

Experience

  • Software Engineer at LangChain
    Mar 2025 - Present · 1 yr 4 mos

  • Pydantic (Remote)
    • Software Engineer
      Jun 2024 - Mar 2025 · 10 mos

      I oversaw the growth and development of widely-used open source Python tools including Pydantic (300M+ downloads / month) and PydanticAI. My work centered on organizing release cycles informed by community demand, driving performance-focused development, and producing exceptional documentation that drove large-scale adoption.

    • Software Engineering Intern
      Sep 2023 - Jun 2024 · 10 mos

      As the lead maintainer of Pydantic, a popular open-source Python library with over 100M downloads per month, I focused on performance optimization, streamlining the v1 to v2 transition for developers, enhancing our high-traffic documentation, and coordinating minor releases with help from hundreds of individual contributors.

  • Full Stack Developer Intern at Quiver Quantitative
    May 2023 - Sep 2023 · 5 mos

    I worked as a backend engineer, using Django and Python to improve our REST API via response speedup, enhanced data validation, and automated documentation generation. I also led projects acquiring and processing new datasets to support innovative visualizations and investing insights on the Quiver website. I led efforts to develop a custom-backtester template, emphasizing ease of development for future products. Finally, I worked to ensure smooth application deployment from development to production via AWS Lightsail.

  • Software Development Intern at Fenris Digital
    Mar 2021 - May 2023 · 2 yrs 3 mos

    I developed a Python-based client library for Fenris’ suite of API products, and used python to design ML model drift detectors for our ML powered API endpoints. Via AWS, I designed and constructed a variety of BI dashboards for internal analytics and customer usage monitoring. I constructed a serverless backend system to facilitate our billing and customer data needs. For all of these projects, I collaborated with an efficient and focused team to thoroughly test and deploy code in CI/CD environments.

  • Software Development and Data Science Intern at Quantworks, Inc.
    Jun 2019 - Aug 2020 · 1 yr 3 mos

    I developed ad hoc and sustainable data analysis solutions with Python, PHP, javaScript, HTML, css, Git, and Wordpress. I learned about the software deployment process, data security and privacy, version control, database management, and software testing methods. Our team built a 2d geo-mapping software with the leaflet javaScript library for PORCH, a local hunger relief nonprofit, to map out volunteer coverage and facilitate volunteer communication. I developed and modified web crawlers with the Scrapy framework for e-commerce sites. I also developed a COVID-19 case dashboard that detailed case counts on a county by county level in parallel with a flask API that delivered demographic data and COVID data.