Xun Cai, Developer in Wollongong, New South Wales, Australia
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Xun Cai

Verified Expert  in Engineering

Back-end Developer

Location
Wollongong, New South Wales, Australia
Toptal 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. He has a master's degree in computer science and enjoys creating stable and scalable APIs and websites that suit customers' needs. Xun earned the Arctic Code Vault badge on GitHub for contributing to many widely-used open-source projects.

Back-endBack-end DevelopmentWeb ServicesWeb ScrapingPythonDjangoREST APIsDjango REST FrameworkPython 3LinuxPostgreSQLPytestUnit TestingDatabasesSQL

Availability

Part-time

Preferred Environment

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

The most amazing...

...thing I've participated in is developing Zine, an app with two million users and three million of daily traffic.

Work Experience

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, Amazon Web Services (AWS), AWS Lambda, ELK (Elastic Stack), Elasticsearch, Python, C++, Node.js, Go, Linux, NGINX, APIs, REST APIs, Kubernetes, Docker

Zine App

https://zine.la/
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, CI/CD Pipelines, Lambda Functions

Platforms

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

Storage

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

2020 - 2022

Master's Degree in Artificial Intelligence

University of Wollongong - Wollongong, Australia