Software Engineer

Pengcheng

Bringing AI into every industry, one business at a time.

Tap the red button

3D Interaction · push the button 33.6°N 117.8°W · MSWE, UC Irvine
01 · About

Mission

What I'm here to do, and the receipts so far.

I'm Pengcheng Xu, a software engineer based in Irvine, California, finishing my MSWE at UC Irvine. I design and ship AI-powered applications, native iOS apps and backend services, where systems thinking, mobile craft and language models meet.

Right now I'm exploring how AI can empower small and medium-sized businesses, forward-deployed style: inside the business, measured on outcomes rather than demos. I'm looking for the right opportunity to build a company around it.

The numbers on this page are what shipped, not what was promised.

Based Irvine, CA
Education MSWE · UC Irvine
Status Building · AI for SMBs
Focus FDE · AI Engineering · Full-Stack · iOS
10K+Users served on a system I shipped
500+TPS sustained on-chain
+23%Recall@5 lift on 50K docs
1stNational prize · team lead
02 · What I build

Systems

Five kinds of things I keep getting asked to build, and build well.

01

AI Systems

Retrieval-augmented platforms and LLM pipelines: hybrid search, citation-grounded generation, multi-dimensional scoring. Designed for recall, latency and refusal, not demo-day magic.

02

iOS Apps

On-device vision, AR navigation and real-time guidance with SwiftUI, AVFoundation, Vision and ARKit. Apple's frameworks pushed past the obvious.

03

Backend at Scale

Spring Boot and Go services, smart contracts, async ingestion, cache strategy and reliability budgets. Boring infrastructure, measured and done well.

04

Full-Stack Products

React and Vue front ends on REST APIs, PostgreSQL, Redis and Kafka. From spec to production, then iterated under real traffic.

05

AI-Native Workflow

Multi-agent coding workflows with Claude Code, Codex and Cursor. Planner, executor and verifier loops that turn intent into reviewed pull requests.

03 · Projects

Flight log

Four featured missions, with the numbers that came back.

01AI · RAG Platform · 2024 — 2025

DevPulse50,000 documents as one searchable mind.

The problem

Engineering teams write more than they can read. Context lives buried in docs, postmortems and Slack threads. Keyword search is shallow and LLMs hallucinate without grounding.

What I built

A retrieval-augmented platform fusing dense embeddings (pgvector) with sparse BM25 via Reciprocal Rank Fusion, with citation-enforced generation and refusal on low confidence, so every answer returns its source.

JavaSpring BootPythonFastAPIpgvectorPostgreSQLRedisKafka
View on GitHub ↗
+23%Recall@5 over a pure-dense baseline on a 50K-document corpus
2services: Spring Boot API tier + FastAPI AI worker, scaling independently, bridged by Redis Pub/Sub
02Blockchain · Carbon Trading · 2024 · National First Prize

GreenTraceChainEvery gram of CO₂ as auditable, on-chain truth.

The problem

Carbon markets run on self-reported emissions and ledgers that can be quietly amended. Regulators see the numbers days or months after they matter.

What I built

A four-role platform on ChainMaker (长安链): enterprises file emissions, auditors review and sign, regulators watch the ledger live, admins mint carbon credits. Led a 5-member team; First Prize at the 2024 China Service Outsourcing Innovation Competition.

ChainMakerGoJavaSpringSmart ContractsECDSA
View on GitHub ↗
500+TPS sustained, +25% throughput vs. baseline, five smart contracts
−35%Average query latency via refined block indexing · ECDSA, SHA-256, AES
03AI · LLM Verification · 2025

DeepNews-LLMScoring news on eight dimensions before you trust it.

The problem

Generative AI made fabricating a believable headline a one-prompt task. Single-signal fact-checkers miss the patterns that make a story feel true while being false.

What I built

A LangChain agent that scrapes the article and scores five internal dimensions plus three external ones, aggregated with AHP × entropy weighting so every verdict is reproducible, streamed back over SSE as the agent thinks.

PythonFastAPILangChainMongoDBRedisSelenium
View on GitHub ↗
90%+Classification accuracy over a labeled benchmark
−40%End-to-end latency via async streaming · 1K+ articles per batch
04iOS · Computer Vision · Swift Student Challenge 2026

FocuspaceA camera that sees with you, not just for you.

The problem

People don't take bad photos because their camera is bad. Nobody ever taught them composition, and the viewfinder is silent.

What I built

Nine composition templates, a breathing diamond that tells you which way to move, and a Vision pipeline for face analysis and subject tracking. Hybrid coach: rule-based scoring plus on-device FoundationModels. −35% shot adjustment time, +28% subject-lock consistency.

SwiftSwiftUIAVFoundationVisionFoundationModels
View on GitHub ↗
Focuspace iPad camera app mockup
Move until it feels right. No language, no menus, just a dot you chase.
More work
04 · Experience

Service record

Shipped to production and measured by people I had to keep happy.

2026 — Present · Irvine, CANow

Founder in progressAI for small and medium-sized businesses

Exploring how AI can empower small and medium-sized businesses, forward-deployed style: embedded in the business, shipping into real workflows and measured on outcomes rather than demos. Looking for the right opportunity, and the right people, to build a company around it.

AI Agents · Forward-Deployed Engineering · SMB
Jun 2026 — Aug 2026 · Silicon Valley

Software EngineerEarly-stage startup, Bay Area

Summer 2026 on an early-stage Silicon Valley team, building and shipping product in a startup environment.

Startup · Full-Stack · AI
Sept 2023 — Sept 2024 · Yiwu, China

Backend Developer InternYiwu Peisha Network Technology Co.

Owned backend modules across the company's commodity-trading platform: the Material Inquiry System, Product Library CRUD and the price-trend visualization API. Took features from spec to production, then iterated on latency and reliability under real traffic.

Java · Spring Boot · MyBatis · MySQL · REST
10K+Active users on the Material Inquiry System, through the full-traffic ramp without incident
−40%Query latency on the hottest path: cache strategy, query-plan rework, N+1 elimination
+30%Reliability on the Product Library CRUD and REST surface: idempotent writes, retry-safe APIs
−20%Latency on the price-trend visualization module, so traders decide in real time
05 · Recognition

Medals

National prizes, regional firsts, an Apple certification and a top-1% scholarship.

01

First Prize · National

2024 China College Service Outsourcing Innovation & Entrepreneurship Competition, National First Prize for GreenTraceChain.

Aug 2024 · Team lead
02

National Innovation Project

National College Student Innovation & Entrepreneurship Training Program, approved at the national level under China's MOE.

2024 · PI
03

National Scholarship

China National Scholarship, awarded to the top 1% of students at the university level.

Nov 2024 · Top 1%
04

First Prize · East China

2025 Mobile Application Innovation Competition, regional First Prize in the East China division.

2025 · iOS
05

Second Prize · East China

2023 Mobile Application Innovation Competition (East China division), for the early iOS prototype that seeded MemoTree.

Jul 2023 · iOS
06

Third Prize · Zhejiang

2023 Zhejiang Provincial College Service Outsourcing Innovation Application Competition, provincial Third Prize.

2023 · Team
07

Apple Certified

App Development with Swift Associate, Apple's international certification for foundational iOS app development.

Sept 2023 · Cert
06 · Contact

Open channel

Building toward a company that puts AI to work inside small and medium-sized businesses. If you're a founder, a forward-deployed team, or a business that wants AI to actually work under real traffic, I'd love to hear from you.