# Chenrui Zhang

- GitHub: [charlottejas](https://github.com/charlottejas)
- LinkedIn: [linkedin.com/in/chenrui-zhang-b63463302](https://linkedin.com/in/chenrui-zhang-b63463302)

## Work Experience

### Coursistant

- Position: Software Engineer
- Location: Los Angeles, CA
- Dates: September 2024 - Present

#### Responsibilities and Accomplishments

- Led end-to-end backend development for an AI-assisted learning platform, defining architecture and implementation plans, allocating tasks, and coordinating delivery with product and engineering teams.
- Developed Spring Boot backend services and exposed RESTful APIs through AWS API Gateway, supporting core application workflows and enabling the AI agent to retrieve and update platform data.
- Reduced average response time for a frequently accessed read API from 700 ms to 200 ms through scheduled Redis cache warming before peak traffic periods, composite MySQL indexes, and database connection pooling.
- Developed an AI agent for instructors and students, integrating API tool calling and RAG to support teaching and learning workflows, including data queries and updates, homework assistance, and study planning.

### NextTier

- Position: Software Engineer Intern
- Location: Sacramento, CA
- Dates: May 2024 - August 2024

#### Responsibilities and Accomplishments

- Designed an event-driven backend on AWS using SQS and Lambda for AI-assisted customer queries, enabling asynchronous intent classification and response generation with high availability and sub-second end-to-end latency.
- Architected a scalable DynamoDB data layer for session and conversation storage, supporting 10K concurrent conversations with single-digit millisecond read latency and 99.9% uptime.
- Developed a comprehensive testing framework with JUnit and Mockito, achieving high test coverage and validating hundreds of end-to-end conversational scenarios in collaboration with backend teammates.
- Implemented CI/CD pipelines with GitHub Actions and AWS CodePipeline using CloudFormation IaC, reducing deployment time by a large margin while enabling zero-downtime releases.

### Psychological Assistance Foundation

- Position: Software Engineer Intern
- Location: Remote
- Dates: May 2023 - August 2023

#### Responsibilities and Accomplishments

- Built and maintained RESTful donation APIs using Spring Boot, MySQL, and Stripe, handling payment creation, payment status notifications, and donation record updates.
- Developed a responsive donation interface using Vue.js, Vuex, and Vue Router, reducing average page load time by 71% through route-based code splitting, lazy loading of noncritical resources, image optimization, and prioritized data fetching.

## Projects

### IBM Coop Project: Data Streaming Platform

- Role: Project Developer
- Location: Remote
- Dates: June 2022 - September 2022

#### Responsibilities and Accomplishments

- Collaborated with IBM engineers to integrate external data sources into an Azure-based data platform using Kafka, enabling reliable real-time data ingestion at scale.
- Developed end-to-end data integration pipelines using Python and Spark, improving processing efficiency and supporting downstream analytics and visualization workflows.
- Configured and operated the Kafka Confluent Platform (Kafka Connect, Schema Registry, Kafka Cluster, Control Center) to process and manage 500,000+ messages per day with high stability and observability.

### Nuomi Player - Android Auto Integration

- Technologies: Java, Android SDK, MediaSession
- Dates: September 2025 - Present
- GitHub: [charlottejas/NuomiPlayer](https://github.com/charlottejas/NuomiPlayer)

#### Responsibilities and Accomplishments

- Developed a Java-based Android Auto integration layer using MediaSession and MediaBrowserService, enabling in-car playback control, synchronized track metadata and album artwork, and lyrics for supported third-party music apps.
- Implemented automatic session recovery with bounded retries and asynchronous callback validation to prevent stale metadata and lyrics during app switching and reconnection; added JUnit and Robolectric regression tests for session replacement and out-of-order updates.

## Selected Skills

- Languages: Java, Python, SQL, JavaScript, TypeScript, C++, Bash
- Backend & Testing: Spring Boot, Spring Security, Hibernate, FastAPI, REST APIs, Maven, JUnit, Mockito, Postman
- Databases & Messaging: MySQL, PostgreSQL, Redis, Amazon DynamoDB, Apache Kafka, Amazon SQS
- Cloud & DevOps: AWS (Lambda, S3, RDS, API Gateway), Docker, Kubernetes, Terraform, Git, GitHub Actions, CI/CD
- AI & Retrieval: RAG, API Tool Calling, LangChain, LangGraph, Pinecone, PyTorch, Apache Tika

## Education

### New York University

- Degree: Master of Science (MS), Computer Engineering
- Dates: September 2023 - May 2025
- GPA: 3.62

### University of California, Davis

- Degrees: Bachelor of Science (BS), Computer Science; Bachelor of Arts (BA), Economics
- Dates: September 2018 - March 2023
- Honors: Dean's Honor List