Jonathan Xu SWE @ Google

New York, NY  ·  Software Engineer at Google

Jonathan Xu

I build backend systems that are supposed to be boring — the kind that hold up millions of disks, millions of queries per second, and the occasional very bad day. Today I work on Google Vids, an AI-native video editor.

10⁶+ queries per second served by an ad-matching framework I launched at Google Ads
Millions of disks managed by the Persistent Disk control plane I helped build
99.999% reliability for storage telemetry at petabyte scale, after an architectural overhaul
8M annual pageviews on a platform I directed with a team of 20+ engineers

Where I've shipped

Five years of building things that other people depend on — control planes, serving systems, ML pipelines, and the product surfaces on top of them.

2026 — Now New York, NY

Software Engineer — Google Vids

Google / Workspace Current

Google's AI-native video editor, part of Workspace. I work on the backend of its editing engine.

  • Audio arrives welded to its video clip. I designed the model change that lets it come apart — an audio clip whose backing data is still the video — and got it signed off.
  • The change wasn't local. The timeline, the export path and the clipboard had each been built on the old assumption, so all three had to move with it — inside an editor already in front of users.
BackendDistributed services API designAI product
Detaching audio from a video clip — and what it does to the model
2024 — 2026 Seattle, WA

Software Engineer — Storage Systems

Google Cloud / Persistent Disk

Google Cloud's block storage. Every disk on every VM is one of these.

  • Millions of disks, worldwide, under SLOs that assume the control plane never stops. I built the distributed services behind create, attach, snapshot, resize and delete.
  • Rebuilt the Storage Pool telemetry stack to five nines at petabyte scale — with a test story that did not exist before.
  • Customers would not sign until those numbers were trustworthy. That unblocked eight figures.
  • Wrote the authoritative design for block storage backup and restore — the system that matters the day something is lost.
  • And the unglamorous half: infrastructure config, productionization, and meta-monitoring — the monitoring that tells you your monitoring is lying.
JavaPythonControl planes SLOsMeta-monitoringFault tolerance
Error budget per 30 days · what each nine costs you
2023 Sunnyvale, CA

Software Engineering Intern

Google / Cloud AI

Google Cloud's generative AI could not launch without customer-managed encryption keys.

  • I built the C++/SQL pipeline that backfilled CMEK across distributed databases. Zero data loss, zero user-visible disruption.
  • Owned it from first commit to launch. It cleared Agent Assist and Dialogflow.
C++SQLEncryption / CMEK Online migration
2022 New York, NY

Software Engineering Intern

Google / Ads

A real-time bidding auction has milliseconds to decide which advert fits a slot.

  • I launched the C++ framework that matches ad-size requests to advertisers inside that path — millions of queries per second.
  • Ramped behind canary tests and global traffic-diversion experiments — in that path a bad match costs revenue on every impression it touches, so nothing goes out on a code review alone.
C++Low latencyRTB Canary / experiments
Slot size in, eligible creatives out — at auction speed
2021 — 2024 Los Angeles, CA

Director

BruinWalk / UCLA Student Media

UCLA's professor and apartment review site, run by UCLA Student Media.

  • 8M pageviews a year. Part of UCLA Student Media's revenue depends on it staying up.
  • Director meant both jobs — roadmap, scope and stakeholders on one side, architecture and code review on the other.
  • 20+ engineers through a full rebuild on Docker, Kubernetes and Nginx across DigitalOcean, AWS and Cloudflare. Active users up 10%.
KubernetesDockerNginx Tech leadership
2021 — 2024 Los Angeles, CA

Undergraduate Researcher

UCLA / Medication Reconciliation Research Group

Two hospitals describe the same prescription two different ways. The gap is where patients get hurt.

  • I wrote the parser and reconciliation algorithm that reads natural-language prescriptions and finds the contradictions — a formal ANTLR grammar over medication instructions.
  • Shipped as a SaaS verifier on a UCLA TRAG grant, integrated with the US National Library of Medicine.
NLPPythonPipelines
2021 San Jose, CA

Software Engineering Intern

Cepton / LiDAR

A LiDAR unit is useless until you know exactly where it sits relative to the others.

  • I built the extrinsic calibration — machine learning over the point cloud to solve the transform between sensors. Beat the customer's precision spec by 60%.
  • Gaussian and kernelized models; K-means and bounding-box regression to clean the stream first.
PythonNumPyscikit-learn Point clouds
Two sensors, one wall — solving for the extrinsic

Things I built because I wanted to

Side projects are where I get to pick the constraints. Lately most of them involve GPUs.

Generative ML

Photoreal diffusion pipeline

Trained a photorealistic personal LoRA on FLUX.2 Dev with ai-toolkit on an A100 80GB, then built a JSON-driven batch inference harness for ComfyUI: one config declares the LoRA, device, seed, steps, guidance, resolution and LoRA multiplier, with per-prompt overrides on top. Hundreds of prompt/parameter combinations render unattended overnight instead of one-at-a-time in a UI.

Quantum computing

Shor's algorithm, three ways

Order-finding implemented in Qiskit three times over — the textbook circuit, a phase-estimation version with the redundant unitary stripped out, and an iterative version that reuses a single ancilla qubit — then run noiseless and again against FakeMelbourne, which models the real error rates of IBM's 16-qubit machine. The textbook circuit's noisy output is unusable static; the trimmed circuit gives clean peaks; the iterative one needs so few qubits that both runs finish in ten minutes. Factored 15, 21 and 63. The honest conclusion was that the algorithm is fine and the hardware is not.

Production

BruinWalk

UCLA's professor and apartment review platform — 8M pageviews a year. I directed the rebuild across Docker, Kubernetes and Nginx on DigitalOcean, AWS and Cloudflare, and architected the search indexing and caching layer over multi-dimensional review data.

Networking

Reliable transport, from scratch

A file-transfer client and server over raw UDP in C++, with no help from TCP: selective repeat with a per-packet timer, receiver-side reordering by sequence number, and AIMD congestion control — additive increase of one packet per RTT, halve the window when a packet outlives its TTL. Tested against a link simulator that drops, delays and reorders traffic on purpose — written for a networking course, and still the clearest thing I've built about why TCP is shaped the way it is.

Parallel computing

One convolution, four machines

The same dense linear algebra across four execution models, each with a different notion of what "fast" costs. OpenMP: 0.62 → 115 GFLOP/s on a 1024³ GEMM through loop permutation and cache blocking. MPI: Cannon's algorithm scaling near-linearly to 88 GFLOP/s at 4096³. CUDA: a CNN kernel from 51 → 585 GFLOP/s, most of it from keeping the accumulator in a register. FPGA: the same kernel through Xilinx HLS onto a U200 at 243 MHz, where the currency is area rather than clock. The loop-order half of that is taken apart in the lab.

Meta

This site

Hand-written HTML, CSS and JavaScript. No framework, no runtime dependencies — the hero simulation, the figures beside each role and the comparison above are all vanilla canvas, a few hundred lines each. Served from Cloudflare's edge as flat files.

Tools & track record

Strongest in systems languages and the infrastructure around them; comfortable enough everywhere else to be useful on day one.

Stack

Proficient
C++ C Python Java SQL Bash Django MapReduce HTML / CSS
Familiar
CUDA MPI OpenMP pthreads PyTorch NumPy scikit-learn Qiskit Xilinx HLS ANTLR OpenCV JavaScript React MongoDB PostgreSQL Haskell Lisp Verilog
Infrastructure & tooling
GCP AWS Cloudflare Kubernetes Docker Nginx Terraform Bazel Protocol Buffers gRPC Spanner Bigtable Elasticsearch Git Mercurial DigitalOcean UNIX

Education & awards

B.S. Computer Science — UCLA GPA 3.99 / 4.00 · Summa Cum Laude · Dean's Honors · 2020–2024
USA Computing Olympiad — Gold Division Top competitor nationally
Ann Tsu-Ann Tai & Kam Sing Tso Centennial Scholarship Awarded in Computer Science, UCLA
4th Place Team — Texas UIL Invitational Computer Science, Houston, TX
Coursework Algorithms · Operating Systems · Databases · Machine Learning · AI · NLP

Contact

Let's build something hard.

I'm most interested in high-leverage backend work — inference and training infrastructure, distributed storage, and low-latency systems where correctness and speed both actually matter. If that's the kind of problem on your desk, send me a note and I'll reply from my own address.

Send a message