Brian Chen

Engineering at Zip

Physics, CS at Columbia University

My name is Brian and I am a software engineer in San Francisco, California.

I love working on difficult technical problems at the forefront of applied AI. I currently work on building AI-native procurement technology as part of the technical staff at {{Zip|https://www.ziphq.com|orange}}.

I have expertise in theoretical machine learning, applied AI, traditional full-stack engineering, and more. I’ve worked at large national research laboratories, series A startups, and everything in between. If you think we could build something special together, let’s get in contact!

/about

I graduated from Columbia University in 2025 with degrees in Computer Science and Physics.

At Columbia, I was associated with many research, education, and outreach groups:

I did {{research|#research|orange}} in theoretical machine learning, applied physics, astrophysics, biomedical engineering, and more.
I {{taught|https://drive.google.com/drive/folders/1Z-dv6Y74nqxKu38CRnwNROFGWolp7H_D|orange}} graduate level {{machine learning|https://www.cs.columbia.edu/~verma/classes/ml/index.html|orange}}, introductory mechanics, E&M, multivariable calculus, and more, spread across Columbia's CS, Physics, and Maths departments. It's in these classrooms where I discovered my love for teaching, and truly many of my happiest hours were spent in front of blackboards in classrooms across campus.
I was president and played competitively for {{Columbia's badminton club|https://www.instagram.com/columbiaubadminton|orange}}, the largest sports club at Columbia with 300+ paid members annually.
I dabbled in {{science outreach|https://www.thecolumbiasciencereview.com/|orange}}, {{wrote|https://drive.google.com/file/d/1fwN97vWjpIehBmOTZG1rIlCjGIVh9rHY/view?usp=sharing|orange}} a lot of {{problems|https://drive.google.com/file/d/1t2Tn5pYnrTDNEV-o19VHNMzzVRzRNcbe/view?usp=sharing|orange}} for Columbia Science Olympiad, was an editor for Columbia's {{philosophy magazine|https://www.thegadflymagazine.org/|orange}}, and {{climbed as many roofs|https://blogs.library.columbia.edu/rbml/2020/04/27/low-library-dome/|orange}} as I could find.

/research

My research experience ranges from the theoretical and mathematical foundations of machine learning to applied physics. Here are some projects that I’m proud of.

B. Chen, Y. Shen, A. Yang, and K. Zhang. Distance Matrix Embeddability Constraints and a Gaussian Noise Corruption Reversal Algorithm. COMS4774 Final Project, 2024.
{{DMCA Paper|https://drive.google.com/file/d/10C07XDrngAuc_5zp1Rge1JMiwCTslbDD/view?usp=sharing|papersymbol}} {{DMCA Poster|https://drive.google.com/file/d/1ke0LIa9dm5bSmuwmPk3qlTMcJFC70pVv/view?usp=sharing|postersymbol}}

B. Chen and N. Verma. Weak Metric Learning. Preprint, 2024.
{{Weak Metric Learning writeup|https://drive.google.com/file/d/1RE1nyvM21XGGDc81LtI7OUjPwktqPgJu/view?usp=sharing|papersymbol}} {{Weak Metric Learning code|https://github.com/nakverma/weak-metric-learning|codesymbol}}

S. Gorgannejad, A. A. Martin, and B. Chen et. al. In situ x-ray imaging to understand subsurface behavior during continuous wave laser drilling. In Applied Physics Letters, 2024.
{{APL paper|https://pubs.aip.org/aip/apl/article-abstract/125/6/064104/3306698/In-situ-x-ray-imaging-to-understand-subsurface?redirectedFrom=fulltext|papersymbol}}

Though these are not strictly research projects, I also learned a ton from my time teaching Columbia's Machine Learning class. Here are a few problems I co-wrote.

B. Chen and A. Yang. Generalized Linear Models. COMS4771 Machine Learning, 2025.
{{GLM Problems|https://drive.google.com/file/d/1CaikvBZPqTbjOIQ7pqefH_E1_LsElSMr/view?usp=drive_link|papersymbol}}

B. Chen and A. Yang. Random forests. COMS4771 Machine Learning, 2024.
{{RF Problems|https://drive.google.com/file/d/1l0DGCNfhwsegyLGcotbwSJFcIHIi2Awo/view?usp=sharing|papersymbol}}

Please contact me directly if you would like to see the solutions for any of these problems.

/development

I am currently a software engineer at {{Zip|https://ziphq.com|orange}}.

I previously worked as a full stack developer at {{IXL Learning|https://www.ixl.com|orange}}, the nation’s largest education technology provider for K-12 schools. I worked on creating new insights for school and district administrators as part of IXL’s admin analytics team.

Before that, I worked at {{Oleria|https://www.oleria.com|orange}}, where I was part of a 3 person team that brought Oleria Copilot, a novel security-oriented GPT, from proof-of-concept to production ready.

/misc

I have an uncountable number of hobbies, one-off projects, side quests, and obscure interests, which unfortunately this margin is too narrow to fully to contain.

Here is a short list of these interests, organized in no particular order:

Badminton, which is by far my favorite thing to do on this planet. You can watch me play {{here|https://youtu.be/QD78ZXcCL88|orange}} (does anyone want to teach me how to smash? 😓)
The Metropolitan Museum of Art, which is maybe the thing I miss most about New York. In college I went as often as I could find the time for (taking full advantage of {{Columbia's Arts Initiative|https://artsinitiative.columbia.edu/|orange}}), to the point where I think I could navigate the museum blindfolded (don't test me on that though).
Physics, which one day when I'm old and tired I think I'd like to go back and relearn properly. Here are some {{compiled problems from my time as a physics major|https://drive.google.com/file/d/1C1TMvdMsXgDLbP4hLh3j_aPmp7LkUdM6/view?usp=sharing|orange}} at Columbia.
{{Physical buttons|https://www.theverge.com/2024/10/16/24272009/amazon-discontinues-kindle-oasis-physical-buttons|orange}} on Amazon kindles.
Math and logic puzzles. I collect them {{here|https://brianxchen.notion.site/fun-problems|orange}}. If you know any good ones PLEASE let me know!
Technology that {{enables creativity|https://figma.com/|orange}}, {{organizes thinking|https://www.notion.com/|orange}}, {{beautifies expression|https://overleaf.com|orange}}, {{democratizes knowledge|https://www.wikipedia.org/|orange}}, and in general treats technology as a tool for enhancing (not replacing) what makes humans special.
This {{dusty cabinet|cabinet.html|orange}} that perhaps you'd like to take a peek in?