Xun Cai, Back-end Developer in Wollongong, New South Wales, Australia
Xun Cai

Back-end Developer in Wollongong, New South Wales, Australia

Member since March 18, 2022
Xun is a back-end developer with eight years of experience in server-side development, Linux server maintenance, and DevOps. He excels in developing back-end web applications, using Django and Express.js, and building CI/CD pipelines with Kubernetes. Although a self-taught programmer, he enjoys creating stable and scalable APIs and websites that suit customers' needs. Xun earned the Arctic Code Vault badge on GitHub for his contributions to many widely-used open source projects.
Xun is now available for hire




Wollongong, New South Wales, Australia



Preferred Environment

PyCharm, Slack, GitLab, GitHub, Bitbucket, Asana, Jira, Django

The most amazing...

...thing I've participated in is developing Zine, an app with 2 million users and 3 million daily traffic.


  • Back-end Architect and Engineer

    2013 - 2020
    Aura Marker Studio Co., Ltd.
    • Built the back end from scratch and scaled up to two million users and three million daily visits.
    • Implemented the automatic horizontal scaling up and down by adopting DevOps practices with Kubernetes. It reduced our VPS cost by 18% and downtime by 82%, which was about a 600% difference in error rates.
    • Built a recommendation system that increased our click-through rate (CTR) by 30% and reduced our bounce rate from 83% to 67%.
    • Developed a malicious IP detection system to help us detect crawler abuses and challenge collapsar (CC) attacks, which saved our computing power by 32%.
    Technologies: Django, Django REST Framework, Microservices, Cloud Native, Amazon DynamoDB, PostgreSQL, MySQL, AWS, AWS Lambda, ELK (Elastic Stack), Elasticsearch, Python, C++, Node.js, Go, Linux, NGINX, APIs, RESTful APIs, Kubernetes, Docker


  • Zine App

    Zine is a well-designed writing and publishing application on smartphones and PCs. It helps users create beautiful typeset content that is easy to personalize.

    I built the back-end application from scratch and led two colleagues. We applied the Agile methodology and used multiple tools such as Trello, Jira, and Asana to track our progress and GitLab as our version control tool and part of our CI/CD pipeline. We maintained a readable, maintainable, and reusable coding standard while practicing the Agile Scrum framework.


  • Languages

    Python, Python 3, Go, JavaScript, SQL, C++, Bash Script
  • Frameworks

    Django, Django REST Framework, Flask, Bootstrap
  • Libraries/APIs

    REST APIs, Node.js, TensorFlow, NumPy, SciPy, OpenCV, Pandas, Matplotlib, Scikit-learn, Vue, React
  • Tools

    NGINX, Pytest, Celery, PyCharm, Slack, GitLab, GitHub, Bitbucket, Asana, Jira, ELK (Elastic Stack), Plotly, RabbitMQ
  • Paradigms

    Object-oriented Design (OOD), REST, Unit Testing, Test-driven Development (TDD), DevOps, Microservices, Agile, Scrum
  • Other

    Back-end, Web Scraping, Back-end Development, Web Services, APIs, RESTful APIs, CI/CD Pipelines, AWS, Lambda Functions
  • Platforms

    Linux, Docker, Cloud Native, AWS Lambda, Kubernetes, Amazon Web Services (AWS), Rancher
  • Storage

    PostgreSQL, Elasticsearch, Databases, Redis, Amazon DynamoDB, MySQL, NoSQL


  • Master's Degree in Artificial Intelligence
    2020 - 2022
    University of Wollongong - Wollongong, Australia

To view more profiles

Join Toptal
Share it with others