Software engineering / systems / products

Jiaxiang Jin (Leo)

Building products and systems that make complicated ideas easier to use and inspect.

Looking for a Summer 2027 software engineering internship
01 / 04 Start with a question 0%

I like turning open-ended ideas into clear, working systems. The best projects make the underlying decisions easy to understand.

Currently learning through shipped products, benchmarks, and experiments.

EXIT 2Work

Projects with a reason to exist.

A few projects where I have focused on useful behavior, inspectable architecture, and honest tradeoffs. Pick one to see the real thing.

A full-stack community application where vehicle history transfers between owners while authorship and access boundaries remain intact.

  • Livedeployed on Vercel
  • RLSrole-based permission tests
  • vPICVIN decoding via NHTSA

PostgreSQL ownership periods preserve authorship and access boundaries. VIN onboarding uses the NHTSA vPIC API, with authentication, public vehicle pages, row-level security, and role-based permission tests.

  • React Native
  • Expo
  • TypeScript
  • Supabase
  • PostgreSQL
  • Vercel
Open repository Visit imsonder.com

A PPO agent, written from scratch in PyTorch, that learns to land a simulated rocket, with held-out evaluation and an honest account of what made training stable.

  • PPOfrom scratch in PyTorch
  • 19 of 20seeds land 90%+ of unseen starts
  • 500held-out landings per seed

A NumPy simulator behind the Gymnasium API, a PPO agent trained from scratch, and an evaluation protocol that checks test seeds never overlap training. Diagnosing why some seeds failed (policies running out of fuel before touchdown) led to a fuel-aware reward: 19 of 20 training seeds now land at least 90% of 500 unseen starts, against 12 of 20 with the original reward. A few seeds are still imperfect, and the repository documents them.

  • Python
  • PyTorch
  • Gymnasium
  • NumPy
imsonder.com
Sonder's home page: every car has a life of its own, with a 3D vehicle passport, a mileage odometer and a start-a-passport button
Live at imsonder.com Row-level security
127.0.0.1:8080
The C++ search engine's browser UI showing a search for 'search index' with the matching document opened
0.026 ms query p95 5,950 articles
rocket-landing-rl / simulation
Autopilot flying Playable in the lab

EXIT 3Lab

See the systems move.

Three projects, three different ways of thinking. Pick one and play with the idea behind it.

    Try this

      2016 Subaru WRXVIN 4S3VA… · illustrative
      odometer0 mi
      View as

        EXIT 4Experience and education

        Learning how good work gets done.

        My current work combines hands-on IT support with software engineering projects. Supporting real users and infrastructure keeps my code grounded in reliability, documentation, and clear problem-solving.

        Read the full resume
        Repair order
        RO-2602
        Opened
        Feb 2026

        IT Support Technician

        Five Star Networking Livermore, CA

        Customer concernHardware, network, and infrastructure issues across client environments, including high-profile assignments at Meta corporate offices.

        • Install and maintain Windows and macOS systemsOngoing
        • Troubleshoot VPN and printer issuesOngoing
        • Manage Active Directory accessOngoing
        • On-site hardware and network supportOngoing
        100+end users supported
        95%+issue resolution rate
        In service
        Build sheet
        A.S. CS
        Est. completion
        B.S. May 2030

        A.S. in Computer Science

        Las Positas College Livermore, CA

        GoalEarn a B.S. and build software for a living.

        • Computing Fundamentals I (C++)Installed
        • Calculus I–IIInstalled
        • Computing Fundamentals IIIn progress
        SJSUplanned transfer
        May 2030anticipated B.S.
        In progress

        EXIT 5About

        Curious by default. Practical on purpose.

        I am a computer science student building toward software engineering. My projects move between systems work, full-stack product development, and the practical discipline of supporting real users and infrastructure.

        Parts catalog

        Every part earned its place.

        Languages4

        Product4

        Systems4

        Infrastructure2

        Also grounded indata structuresalgorithmsdata modelingautomated testingaccess control

        EXIT 6Off the clock

        450 miles at ground level.

        Away from the keyboard I'm a car person, and this site is built around one night on the road.

        1. Mile 000 · San Diego · 2:00 AM

          The air suspension pump fails. All four airbags go flat, and the car is sitting on the ground.

        2. Mile 001

          No tow truck. I head north alone, with the music all the way up.

        3. Mile 225

          Still on the ground. Still going.

        4. Mile 450 · The shop

          I drive straight to my mechanic friend's shop. No way you drove all the way here from San Diego like that.

        EXIT 6ACommunity

        1,000+

        members in the Bay Area car club I started, grown by word of mouth.

        I also host our car meets.

        For a long time I felt out of place. The car community is where I found people I belonged with, and I want to build spaces where other people can find that too.

        RESUMEThe one-page version

        Read the window sticker.

        Every new car has a spec sheet in the window. Here's mine. The full PDF has the details.

        Open resume

        Software engineer · Summer 2027 internship

        Jiaxiang Jin (Leo)

        Assembly point
        Livermore, CA
        Status
        Available

        Standard equipment

        Languages
        C++, Python, TypeScript, JavaScript
        Product
        React Native, Expo, Supabase, PostgreSQL
        Systems
        CMake, SQLite, libcurl, PyTorch
        Infrastructure
        GitHub Actions, Vercel

        Installed options

        • Sonderfull-stack product, live
        • C++ Search Enginesystems, benchmarked
        • Rocket Landing RLPPO from scratch

        Performance

        0.026ms p95 query time, C++ search engine
        19/20RL seeds land 90%+
        95%+IT issue resolution

        Service history

        Feb 2026 – now
        IT Support Technician, Five Star Networking. 100+ end users.
        In progress
        A.S. Computer Science, Las Positas College; planned transfer to San José State. B.S. anticipated May 2030.