I'm a Melbourne-based full-stack software developer with commercial experience building React, TypeScript and Node.js applications for SaaS platforms, internal tools and AI-assisted workflows.
My strongest fit is with teams that need practical ownership across product UI, API contracts, authentication, data workflows, testing, cloud delivery and AI features with engineering guardrails.
- Currently working as a Freelance Full-Stack Developer & Consultant
- Recently worked on AI SaaS microservices at ByteCroniX, including API performance, GCP/GKE services, CI/CD and test coverage
- Built an Expresso Carwash management portal that digitised spreadsheet workflows and saved approximately 6 hours per week per site
- Building AI workflows with structured outputs, Zod validation, privacy boundaries, retry/backoff and observability
- Portfolio: liuyuelin.dev
- Blog: blog.liuyuelin.dev
- Resume: Yuelin Liu Resume
- Email: liuyuelintop@gmail.com
- LinkedIn: linkedin.com/in/liuyuelintop
- Full-stack product delivery with React, Next.js, TypeScript, Node.js and Express
- SaaS and internal-tool workflows with auth, dashboards, APIs and operational data
- Cloud and release confidence with Docker, Kubernetes, GitHub Actions, AWS and GCP
- AI-enabled workflows with OpenAI, Gemini, DeepSeek, Bedrock, Zod and structured outputs
A privacy-first multi-LLM finance pipeline that transforms timecard images into structured financial audits with local validation, masking and fault-tolerant Telegram delivery.
- Built a TypeScript/Node.js workflow using Gemini Vision for OCR extraction and DeepSeek for financial reasoning
- Designed nested Zod schema validation to constrain and verify AI-generated structured outputs before use
- Computed financial metrics locally and masked raw financial values before sending anonymized payloads to external LLM APIs
- Added retry/backoff handling and timestamp throttling to prevent rate-limit failures during high-frequency Telegram updates
Tech: TypeScript, Node.js, Gemini, DeepSeek, Zod, Telegram Bot API, OCR, structured outputs, data masking
A cloud-native multi-agent wealth-planning platform where five AI agents coordinate portfolio planning, classification, reporting, investment-charter generation and retirement analysis on AWS.
- Orchestrated five domain agents through event-driven AWS workflows using Lambda, SQS and Amazon Bedrock
- Built async execution paths with structured outputs, tool calls, database writes and retry handling
- Designed a cost-conscious RAG layer with S3 Vectors and SageMaker embeddings, reducing vector storage cost by approximately 90% versus an OpenSearch-style setup
- Provisioned infrastructure with Terraform across permissions, research ingestion, agents, frontend delivery and enterprise guardrails
- Added LangFuse traces, CloudWatch dashboards and least-privilege IAM controls
Tech: Next.js, TypeScript, AWS Lambda, SQS, Bedrock, Terraform, Aurora Serverless v2, S3 Vectors, SageMaker, CloudFront, API Gateway, Clerk, LangFuse, CloudWatch
An open-source Next.js 15 platform for sports club management, player statistics and community engagement.
- Built a modular club-management platform for events, announcements, player statistics and community workflows
- Implemented responsive dashboard layouts for multi-device use by players, admins and community members
- Designed the project as a reusable template that can be adapted by other clubs and teams
Tech: Next.js 15, TypeScript, Tailwind CSS, shadcn/ui, MongoDB, Vercel
Frontend:
React | Next.js 14/15 | TypeScript | JavaScript | Tailwind CSS | HTML5 | CSS3
Backend:
Node.js | Express | REST APIs | JWT | OAuth | Session Cookies
Databases:
PostgreSQL | MongoDB | MySQL | Firebase | Convex | Vector Databases
Cloud & DevOps:
AWS Lambda | S3 | ECR | GCP GKE | Docker | Kubernetes | Terraform | Nginx | GitHub Actions | Vercel | Render
Testing & Quality:
Jest | Supertest | Playwright | React Testing Library | API Testing | Regression Testing
AI & LLM:
OpenAI SDK | Gemini | DeepSeek | Amazon Bedrock | LangChain | Structured LLM Outputs | Agentic Workflows | Zod
Tools:
Clerk | Git | GitHub | Postman | Jira | Confluence | Slack | VS Code