CW Changyu Wang Software Engineer
中文

Work

Work

My experience centers on backend services, AI Agent / RAG systems, internal platforms, API delivery, automation tools, and performance optimization. This page groups the project evidence recruiters usually need first.

CASE

Selected Projects

AI Agent / RAG

Technical Documentation RAG Retrieval System

Built an internal technical-document retrieval pipeline with Python, FastAPI, LangChain, DeepSeek, and Elasticsearch, supporting keyword search, semantic retrieval, hybrid search, and document recall.

  • Implemented retrieval services and recall flows
  • Helped engineers find historical solutions and internal knowledge
  • Applied AI Agent capability to real backend workflows
Performance

Internal System Performance Optimization

Optimized slow queries, high-frequency APIs, and database access paths. Through SQL tuning, indexes, caching, and request-flow adjustments, reduced a core API response time from about 800ms to about 200ms.

  • Analyzed slow queries and repeated requests
  • Reduced database pressure
  • Improved response speed and service stability
Tooling

Automated API Upload Tool

Turned a repetitive process with around 40 parameters and 160 metadata fields per API into a tool-driven workflow for validation, organization, and upload.

  • Saved about 10 hours of repetitive work per person each week
  • Improved API test-submission efficiency
  • Converted manual preparation into reusable tooling

TIMELINE

Experience

Software Engineer

Great Wall Motor Co., Ltd. Beijing Branch · Beijing

  • Worked on AI Agent and backend projects, including a technical-document RAG retrieval system and Hi-Learning City.
  • Delivered internal backend APIs, performance optimization, database access improvements, and automation tools.

Software Engineer

Beijing Kingfisher Visual Technology Co., Ltd. · Beijing

  • Contributed to the 3DView platform for 3D model display, data management, product presentation, and design collaboration.
  • Used Flask and Python-SocketIO to support real-time communication and backend services.

Software Engineer

Toshiba (China) Co., Ltd. · Beijing

  • Focused on Python backend development, working on time-tracking systems, API design, database modeling, deployment, and testing.
  • Contributed to an image translation and recognition project involving OCR, translation, and image processing.

STACK

Technical Stack

Backend And Services

Python, Go, FastAPI, Flask, Gin, gRPC, Python-SocketIO

AI Agent / RAG

LangChain, DeepSeek, Pydantic, Elasticsearch, Tools, Memory, Planning

Data And Infrastructure

MySQL, Redis, MongoDB, Docker, K8s, Nginx, Jenkins, Kong