Sicheng Ouyang

Projects

Project work aligned with my current resume, with architecture notes and implementation details from public repositories.

Project 01

2025-2026

Chat WebSocket Demo

GitHub Repo

Project Summary

Real-time chat system with FastAPI + WebSocket backend, PostgreSQL persistence, and Next.js frontend.

Stack

Delivered

  • Implemented JWT authentication and email verification to block unverified access.
  • Added paginated REST message history and incremental WebSocket sync for stable reconnect behavior.
  • Documented structured API error codes and applied rate limiting controls for safer traffic handling.
Architecture Flow

flowchart LR
  U[Next.js Client] -->|HTTP + JWT| A[FastAPI API]
  U -->|WebSocket| W[Realtime Gateway]
  A --> E[Email Verification]
  A --> R[Rate Limiter]
  A --> P[(PostgreSQL)]
  W --> P
  A --> H[Paginated History API]

Technical Challenge

Realtime delivery quality depends on keeping API consistency, sync semantics, and auth boundaries aligned under reconnect-heavy conditions.

Next Iteration

  • Introduce conversation-level delivery acknowledgements to improve replay precision.
  • Add load-testing scenarios for large group conversations and backpressure behavior.

Project 02

2025-2026

Todo List Web & Desktop App

GitHub Repo

Project Summary

Full-stack task manager built for both browser and desktop tray usage with natural language task input.

Stack

Delivered

  • Built full CRUD task flows with a React + Flask + MySQL stack.
  • Packaged a cross-platform desktop tray app for both macOS and Windows usage.
  • Fine-tuned BERT-based parsing to convert natural language input into structured task JSON.
Web/Desktop System Flow

flowchart TD
  UI[React Web UI] --> API[Flask API]
  TRAY[Desktop Tray App] --> API
  API --> DB[(MySQL)]
  NLP[BERT Parser] --> API
  API --> OUT[Task JSON + CRUD Results]

Technical Challenge

Maintaining behavior parity between web and desktop clients requires strict API contracts and normalization of input parsing outputs.

Next Iteration

  • Add optimistic updates with conflict resolution for concurrent edits.
  • Improve parser confidence scoring and fallback prompts when intent is ambiguous.

Project 03

2025

Bookkeeping Command-Line Tool

GitHub Repo

Project Summary

Python CLI bookkeeping tool with modular command structure and persistent expense data storage.

Stack

Delivered

  • Implemented command parsing with argparse and modular command handlers.
  • Added local file persistence for expense tracking and retrieval.
  • Kept interfaces simple and scriptable for fast personal usage loops.
CLI Interaction
$ bookkeeping add --amount 24.50 --category food --note lunch
saved: expense#142
$ bookkeeping add --amount 89.00 --category transit --note presto
saved: expense#143
$ bookkeeping summary --month 2026-02
food ............. 24.50
transit .......... 89.00
total ............ 113.50

Technical Challenge

CLI usability depends on concise output formatting and predictable command behavior across additive and query operations.

Next Iteration

  • Add category-level analytics and monthly summary reports.
  • Support CSV import/export for easier migration and external analysis.

Project 04

2025

Nurel AI Playground

GitHub Repo

Project Summary

A team-built local AI experimentation web app for model training controls and real-time training visualization.

Stack

Delivered

  • Built with a team of 4 to provide configurable hyperparameter controls in a browser UI.
  • Connected FastAPI training endpoints to real-time frontend charts for experiment monitoring.
  • Optimized for local execution to keep iteration fast for exploratory workflows.
Experiment Loop

flowchart LR
  U[Researcher UI] --> C[Hyperparameter Config]
  C --> A[FastAPI Training API]
  A --> T[Training Worker]
  T --> M[Metrics Stream]
  M --> V[React Visualization]
  V --> U

Technical Challenge

The hardest part was keeping training-state updates consistent between backend jobs and frontend visual state during frequent parameter changes.

Next Iteration

  • Add experiment versioning and comparison between multiple runs.
  • Introduce resumable training jobs with checkpoint-aware UI state.

Project 05

2025

Resume Analyzer

GitHub Repo

Project Summary

Resume evaluation app that integrates OpenAI APIs to generate structured, actionable feedback.

Stack

Delivered

  • Built upload-to-feedback workflow with clear section-level output for resume improvements.
  • Integrated OpenAI APIs to convert raw resume text into structured evaluation points.
  • Focused on deterministic response formatting so users can iterate quickly.
Feedback Generation Sequence

sequenceDiagram
  participant User
  participant React as React UI
  participant Flask as Flask API
  participant OpenAI as OpenAI API
  User->>React: Upload resume
  React->>Flask: Submit parsed content
  Flask->>OpenAI: Request structured feedback
  OpenAI-->>Flask: Return JSON suggestions
  Flask-->>React: Return formatted sections
  React-->>User: Render actionable report

Technical Challenge

LLM-based feedback quality depends on prompt structure, output schema consistency, and robust handling of incomplete resume inputs.

Next Iteration

  • Add scoring rubrics by role type (SWE, data, ML) for more context-aware feedback.
  • Store revision history to compare resume quality improvements over time.

Project 06

2025

LaTeX Resume Template

GitHub Repo

Project Summary

A reusable LaTeX resume template focused on clean hierarchy, readable typography, and fast customization.

Stack

Delivered

  • Designed a structured one-page resume layout with consistent spacing and section rhythm.
  • Added simple, reusable macros to speed up editing across education, project, and experience sections.
  • Kept the template lightweight so it compiles quickly and exports ATS-friendly PDFs.

Technical Challenge

Balancing visual polish with ATS readability required careful control of formatting commands and text semantics.

Next Iteration

  • Add alternate style presets for internship-focused and research-focused versions.
  • Provide bilingual content placeholders to simplify English/Chinese resume maintenance.

Project 07

2023-2024

Obsidian Oreo Theme

GitHub Repo

Project Summary

A custom Obsidian theme focused on readable contrast and a polished Oreo-inspired visual style.

Stack

Delivered

  • Designed and implemented a complete custom theme package for Obsidian.
  • Published the theme with community adoption exceeding 3,000 downloads.
  • Balanced aesthetics with practical readability for long-form note taking.

Technical Challenge

Theme work required handling many edge UI states while keeping a coherent visual language across plugins and markdown content patterns.

Next Iteration

  • Add broader plugin-specific style coverage and maintain compatibility across app updates.
  • Ship accessibility-focused variants with stronger contrast presets.