FullstackBackendMobile
JavaJavaScript
InternationalAustraliaChina
Yingchen Liu
Senior Full-Stack Engineer
•
8 years
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Web Frontend, Backend, Cloud, Mobile
info@yingchenliu.com
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https://yingchenliu.com
EXPERIENCE
Freelance Software Engineer
- Remote, China
July 2024 - Current
Self-Employed
  • Designed and developed a scalable backend system using TypeScript, Node.js with GraphQL and PostgreSQL, deploying to AWS with Docker and Terraform.
  • Migrated an Android codebase from Java to Kotlin and upgraded to Bluetooth 5, enhancing data transfer range, and connection stability for medical hardware.
Senior Software Engineer
- Remote, China
Jun 2022 - May 2024
Aimi.fm
  • Led the development of a cross-platform music SDK, a core component of Aimi Player and Aimi Studio, in TypeScript, Node.js and C++, enhancing the dynamic and personalised music experience and reducing startup time by 52%.
  • Deployed a scalable music streaming backend and maintained AWS infrastructure using Docker, Terraform, and GitHub Actions. Improved the build flow, reducing service build time by 30 seconds.
  • Engineered responsive web applications with TypeScript, React, Next.js with GraphQL and DynamoDB. Deployed on Vercel.
  • Achieved 96% test coverage by implementing test-driven development within the team.
"I just want to say that I've really appreciated working with you. You've been incredibly helpful, hardworking, and very easy to get along with."
- J. Curtis (Senior Software Engineer, Aimi.fm)
Software Consultant
- Hybrid, Australia
May 2021 - Jun 2022
Cognizant Servian
  • Engagement Lead at Optus:
    • Led discovery sessions and collaboratively defined project scope with Optus. Negotiated interface contracts with other systems, produced detailed solution design documentation. Managed stakeholders, budget, risks and timeline.
    • Led an Agile team of 3: organised, facilitated team ceremonies, conducted code reviews, and mentored junior engineers.
    • Designed and developed a highly available and secure cloud solution for both backend and frontend using Java, Spring Boot, TypeScript, React and Redux; deployed on GCP Kubernetes with API Gateway using Docker and Terraform.
    • Designed database schema on Cloud Spanner (SQL), leveraging its horizontal scalability and strong consistency for seamless user experiences.
  • Backend Engineer at Airtasker:
    • Engineered new backend microservices in Kotlin and Spring Boot on AWS, cutting web and mobile app load time by over 50% while boosting performance, responsiveness, and maintainability.
    • Developed a dynamic Android UI leveraging Kotlin and JetPack Compose; added a new flow to boost user retention by 17%.
    • "You put in an incredible effort to handle ALL the backend work and push Android across the line with Alex. You've worked tirelessly, right up until the last day, to ensure everything was completed before your departure, and for that, we're incredibly grateful! Thanks for being a gun engineer and making this project a success. We couldn't have done it without you."
    - Mitchell Weiss (Tech Lead Manager, Airtasker)
  • Cloud Engineer at Lendlease:
    • Trained a ticket classification model with Python and Pandas on GCP Vertex AI, integrated with Lendlease's ServiceNow using a Python backend and Pub/Sub, reducing the need for 30 staff members for manual classification tasks.
    • Created a chatbot backend using Python, Cloud Functions (Lambda), and Dialogflow.
    • "Yingchen is one of the best developers I have ever worked with."
    - John Kelaita (Principal Consultant, Cognizant Servian)
EXPERIENCE
Full-Stack Developer
- Hybrid, Australia
Jun 2018 - Apr 2021
Strength By Numbers
  • Designed and developed the Android app in Java, managing complex multi-threaded and asynchronous Bluetooth operations using ReactiveX.
  • Built backend microservices using Java, Spring, Docker and MongoDB, deployed on AWS, supporting over 200 physio/fitness centers.
  • Developed Single Page Applications with React and Redux.
Full-Stack Developer
- Part-Time, Hybrid, Australia
Sep 2016 - May 2018
SensiLab
  • Designed and developed full-stack web applications using React, Redux, Express.js, MongoDB and Firebase.
  • Developed an iOS app using Swift.
  • Optimized SensiLab's WordPress website and created custom themes and plugins.
EDUCATION
Master of Information Technology
- Melbourne, Australia
2016 - 2017
Monash University (QS: 37)
  • Dux of Postgraduate Information Technology Award (Top 1 Student).
  • International Merit Scholarship, and Winter Research Scholarship.
  • Achieved the highest grade in 4 subjects: programming, distributed systems, mobile and advanced mobile.
SKILLS
  • Languages: Java, Kotlin, JavaScript (ES6), TypeScript, Swift, Python, C, C++
  • Frameworks: Spring Boot, React, Node.js
  • Databases: MySQL, PostgreSQL, DynamoDB, MongoDB, Neo4j, Redis, Firebase
  • Mobile: Android, Jetpack, iOS
  • Cloud: AWS, GCP, Kubernetes, API Gateway, Lambda, Message Queue, Vercel
  • Tools: Docker, Terraform, Git, CI/CD, Jira, Bash