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Congkai ZhangCZ

Congkai Zhang

SoftwareEgineer

€302/day
Hayward, US
8-15 years

Average response time: 1 hour

About Congkai

I’ve been working as a Software Developer for over 6 now. I started off by learning to build simple applications and slowly grew into handling more complex projects. Over time, I became really interested in both backend and frontend development, and I got the chance to work with technologies like React, Node.js, and Django.

As I gained more experience, I started taking on larger projects, designing systems that could handle more traffic and scale as needed. I also took on leadership roles, where I helped guide junior developers, reviewed code, and made decisions about how things should be built.

Along the way, I gained hands-on experience with AI technologies, including machine learning models, natural language processing (NLP), and data-driven decision-making. I’ve worked on projects that involved integrating AI into applications to automate tasks, improve user experiences, and enhance business processes.

I’m passionate about building efficient, clean code that solves real problems and delivers value. I enjoy working with teams, solving tough problems together, and learning about new technologies, including AI and machine learning. My journey has been about growing as a developer, learning from mistakes, and always trying to improve.

In short, I love coding, and my goal is always to create software that works well, scales smoothly, leverages the power of AI, and makes life easier for users.
  • English

    Native or bilingual

  • Chinese

    Native or bilingual

Remote only
Primarily works remotely

Experience

  • Builder.ai
    Software Engineer
    REAL ESTATE
    January 2023 - August 2025 (2 years and 7 months)
    Santa Monica, United States
    • Developed and scaled platform components that supported automated code generation and modular feature assembly, helping reduce development time for client apps.
    • Worked with cross‑functional teams to integrate AI models into development workflows, improving efficiency of feature templates and predictive logic.
    • Contributed to backend APIs and services using Python (Django/Flask) and collaborated on frontend enhancements in React to improve the builder dashboard and user experience.
    • Implemented robust testing, CI/CD pipelines, and deployment automation to ensure efficient deliveries across staging and production environments.
    • Partnered with product and design teams to ship usable capabilities rapidly, iterating on feedback and performance insights.
    • Helped debug and resolve complex issues under tight timelines-maintaining operability during high‑impact sprints.
    Python Next.js Kotlin RESTful API OpenAI
  • Consolidate Health
    Software Engineer
    HEALTH AND WELLNESS
    May 2022 - November 2022 (6 months)
    Boston, United States
    • Improved system performance by optimizing critical workflows, which reduced load times by 30%.
    • Deployed a key feature update to over 10,000 users, receiving positive feedback on performance improvements and user satisfaction.
    • Reduced bug turnaround time by 40% by implementing a faster debugging and patching process.
    • Contributed to a product launch that led to increased customer acquisition and helped secure over $100K in new business.
    React/Next Node.js OpenAI Android Python
  • Zilingo
    Full Stack Engineer
    E-COMMERCE
    July 2020 - March 2022 (1 year and 8 months)
    Singapore, Singapore
    • Delivered a scalable e-commerce platform that handles thousands of transactions per day, improving overall user experience and conversion rates.
    • Optimized backend APIs, reducing response times by 40%, and improved frontend performance by implementing lazy loading and caching strategies.
    • Integrated cloud services like AWS S3 for file storage and AWS Lambda for serverless computing, reducing operational costs by 25%.
    • Led the migration of a legacy application to a modern tech stack, reducing technical debt and simplifying future updates.
    React.js Node.js Java MySQL GraphQL

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Education

  • BS
    University of Michigan in 2020 - 2022
    2020

Skill set

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