Yizhou (Russell) Lu · Software Engineer — AI Applications & Full Stack

I build AI applications with evidence behind their decisions.

My work spans LLM-powered products, data-quality evaluation, and the full-stack systems around them. I focus on making results explainable, failures recoverable, and releases verifiable.

MS in Computer Science, USC · Class of 2027 Seeking AI / LLM engineering and full-stack roles

Flagship — JobSignal

JobSignal — explainable job matching.

Resume in, ranked visa-friendly jobs out. Claude extracts a candidate profile, pgvector retrieves listings sourced from public Department of Labor filings, and an LLM reranker writes a rationale for every match.

Live Ingestion repair merged · CI passing Production acceptance pending

Selected cases

Two more pieces of work with a written case each: a development tool I built and use, and my internship engineering.

Developer tooling

Cross-LLM Development Workflow

Task routing, independent review, and verifiable delivery

Built a reusable local CLI for routing development tasks across LLM providers, with isolated workspaces and traceable run evidence. Used it within a coordinated workflow for a JobSignal repair pilot and the LLM Interview Lab delivery, keeping execution success separate from acceptance.

Local CLI preview Cross-model routing Independent review

Internship engineering

FreshLens

Release verification for a computer-vision product

Contributed release-verification tooling to FreshLens during my TalkMeUp internship, including deterministic gate orchestration, shared result contracts, and reproducible evidence for review and handoff. Earlier in the internship I worked on YOLOv8 produce detection.

Orchestrator merged Some materials in review

More engineering work

An evaluation case, a full-stack SaaS, and the public half of my delivery process.

Product-price identity evaluation

A conservative LLM check that vetoes a price match when the product identity does not line up: wrong model, accessory, bundle, or another item that should not be mixed in. Deterministic rules handle the clear-cut conditions; the model only reviews semantics and never generates a price. Measured false rejections, missed mismatches, repeatability, latency, and cost separately, before any production integration.

Offline evaluationNot in production

team system · my scope: the veto layer and its evaluation

AI Work Observer

Evidence-backed delivery tracking. Links GitHub events to work-item state so progress is grounded in what actually happened: deterministic rules draw the conclusions, AI explains them. Full-stack SaaS built around OAuth, webhooks, native work items, and background processing. A preview is deployed, but the product is not fully functional yet; the source shows the current state.

In progressPreview deployed · not fully functional

agent-harness-pack

Role templates for implementation and independent review, delivery rules, CI templates, and lessons learned from running AI-assisted delivery. The public, reusable templates behind the workflow above; the CLI itself is a separate private preview.

Public repository

github.com/RussCTGL/agent-harness-pack ↗

Learning & writing

Where I turn what I'm studying into tools I can maintain.

LLM Interview Lab LIVE

A self-directed AI fundamentals learning app with 150 practice questions, 98 knowledge notes across 16 modules, strict multi-select grading, and in-browser progress recovery. Built with content validation and independent review before release. Content ships with the site; it does not call an LLM at runtime.

llm-interview-lab.vercel.app ↗

Applied NLP Notes LIVE

Bilingual notes for USC CS544 (Applied NLP), organized by topic and linking concepts, worked examples, formulas, and sources. Follows the course lectures and credits them; not an original curriculum.

CatalogMatch

Team course project on product catalog matching: problem framing, abstention with human review, and experiment design. No trained results yet; baseline and error analysis to follow.

In progressTeam project

More work

Experience

The short version. The full version is on my resume.

TalkMeUp Software Engineer Intern · Jun–Aug 2026 · Los Angeles

FreshLens scores produce freshness with computer vision. I started on YOLOv8 detection and finished owning release verification for the team.

  • Turned release criteria from prose into runnable checks tied to commands, exit status, and artifacts.
  • Defined a shared gate-result contract so different workflows could submit evidence while keeping pass, blocked, and uncertain states distinct.
  • Fixed problems that broke reproducible runs and documented handoff for the parts still unfinished.

Gate orchestrator mergedSome materials in review

Case study →
Baowin Steel Software Engineer Intern · May–Aug 2025 · Houston

Built a full-stack e-commerce trading platform (Django, React, MySQL) with authentication, listings, and transactions; designed its REST APIs and moved it from on-prem to AWS (EC2, RDS) with CI/CD.

Lark Technologies Software Engineer Intern · May–Jul 2024 · China

Built an AI bot that automated Google Sheets workflows, replacing roughly two weeks of manual customer analysis with a few hours of unattended batch processing.

Education USC · UW–Madison

MS in Computer Science, University of Southern California, Aug 2025 – May 2027. Coursework includes Applied NLP (CS544).

BS in Computer Sciences and BS in Mathematics, University of Wisconsin–Madison, 2022 – 2025.

How I validate AI-assisted delivery.

Much of my recent work is built with AI coding tools across several models, so my job is defining the requirement, reviewing the evidence, and deciding what ships. One recent run exited successfully, but its run evidence did not cover the acceptance criteria. It went to awaiting verification instead of done, and was reworked. A successful exit is not acceptance.

New tests must fail firstA test is only evidence if it failed against the unfixed code. Where it matters, a mutation check confirms the guard is what makes it pass.
Approvals bind to a commitInputs, commits, and run evidence are saved with every task. One more push, and the review starts over.
Execution success ≠ acceptanceQuality approval is never granted automatically. Tools have no production access; the merge and the release call are mine.
How the workflow is built →

Hiring for AI application engineering?

MS CS at USC, Class of 2027. Seeking AI / LLM engineering and full-stack roles where model output has to be explainable and releases have to be verifiable.

0109yizhoulu@gmail.com