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William Lei
Full Stack Developer
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William Lei

Full Stack Developer
•Senior engineer with full-stack experience specializing in front-end, React and React Native enthusiast who truly loves Typescript. •Experienced working in big corporations, small startups and as a solo developer—planning architecture, setting up the CI/CD, coding applications, and deploying them to a server or an app store. •Communicated with other teams and senior management to adapt 50+ clients’ websites to adapt to changing industry standards. •Built a large scale front-end code base by using React hooks to build complex components such as a virtualized list, combined strict types, functional-style code and Jest unit tests.
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The University of Hong Kong
Gloversville, NY, USA

Professional Background

  • Current status
  • Profession
    Full Stack Development
    Front-end Engineer
    App Developer
  • Fields
    Mobile Apps
    Information Services
  • Work experience
    6-10 years (6-10 years relevant)
  • Management
    I've had experience in managing 10-15 people
  • Skills
    React Native
    Tailwind CSS
    Material UI
    Flutter App Developement
  • Languages
    Native or Bilingual
  • Highest level of education

Job search preferences

  • Desired job type
    Remote Only
  • Desired positions
    Senior Front-End Engineer / Full Stack Developer
  • Desired work locations
    Hong Kong
    United States
    United Kingdom
  • Freelance
    Full-time freelancer

Work Experience

Full Stack Next/Firebase Engineer

Apr 2023 - Present
Atlanta, GA, USA
- Collaborated with the design team to implement a new user interface that resulted in a 20% increase in user satisfaction. - Implemented server-side rendering using Next.js, resulting in a 30% improvement in page load times. - Developed a custom analytics dashboard using Firebase, providing real-time insights into user behavior and increasing conversion rates by 10%. - Conducted over 3 code reviews per day, resulting in a 50% reduction in code defects. - Increased user interaction rate up to 25% by using email services with SendGrid Email, Firebase Notification. Technologies: Next.js, TypeScript, Firebase Admin SDK, Firestore, SendGrid Email Service, Twillo

Full Stack Web & Mobile Developer

Jan 2023 - Apr 2023
4 mos
Santa Clara, CA, USA
- Defined and implemented the initial app architecture and framework. - Delivered a POC and MVP with over 300 native pure components and screens on a very tight schedule. - Reduced development cycles by up to 25% by guiding backend and Android teams through mobile API definition and implementation details. - Used and contributed to backend and DevSup projects (PostgreSǪL, gRPC, Node.js and Google Cloud). - Contributed CI, deployment, and other tools needed to maintain and deploy apps. - Introduced several handy patterns to simplify the writing of unit and instrumentation tests and speed up development by 30%. Technologies: React, React Native, Kotlin SDK, Android, Express, TypeScript

Full-stack Developer

Mar 2021 - Nov 2022
1 yr 9 mos
United States
•Re-coded application using React, which shortened page load times by up to 65%. •Migrated an application toward the cloud, reducing hosting costs for the client by 50%. •Designed the application architecture on TypeScript, React and Redux and accelerated the development rates by 15%. •Handled nearly 5+ production tickets per day, 100+ tickets per month with respect to live customer trouble ticket resolution. •Contributed as part of a team that made a huge, enterprise app for our biggest client which is being used worldwide by the client's employees. Technologies: React, Redux/Thunk, TypeScript, OAuth 2, Django, Node.js

Senior Front-end Engineer

Jun 2019 - Feb 2021
1 yr 9 mos
United States
•Worked closely with the product team to build intelligent search functionality in React for an ecommerce site with a catalogue of 5000 products leading to an increase in page views per session of 22%. •Improved the page load speed by 15% for an e-commerce site by leveraging browser caching and improving server response times. •Utilized the Node.js and GraphQL to create APIs for both internal and external use reducing the time to ship new front-end features by 4% Fresh Direct. •Built extensive test coverage for all new features which reduced the number of customer complaints by 7%. Technologies: React, React/Thunk, Node.js, GraphǪL, RESTful API

Front-end Developer

Sep 2017 - May 2019
1 yr 9 mos
Hong Kong
•Developed product tours with React for a new feature, improving customer adoption by 25% leading to increased revenue by $1M. •Created a compatible, custom client dashboard, reducing support tickets by 45%. •Worked with UX/UI design teams to improve existing applications and increase conversion rates by 20%. •Supported the QA team to design test cases for various change requests and enhancement. Technologies: React, HTML5, CSS, JavaScript, Tailwind CSS, Material UI

Front-end Developer Intern

Aug 2016 - Aug 2017
1 yr 1 mo
Hong Kong
•Translated the design team’s UX wireframes and mockups into responsive, interactive features using HTML, CSS, and JavaScript that increased user engagement on page by over 200%. •Provided strategic advisory on design and development processes, initiating revamped structures and systems to ensure a consistently high level of quality. •Researched, established, documented, and maintained company coding best practices, development organization, and workflow standards. •Collaborated with the agile team to migrate a 30+ page legacy company website to React and Sass. Technologies: React, PHP, SCSS, JavaScript, CSS3, HTML5, ECMAScript (ES6)


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Bachelor of Engineering (BEng)
Computer Science
2012 - 2016