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Ju Hang Sin


Ju-Hang Sin

Software Engineer


Software Engineer at Bad Gateway Inc. Toronto, Canada, Nov/2019 – Present

Bad Gateway is a Toronto-based software development agency. The agency specializes in building APIs and web Applications for clients.


Responsible for building REST APIs. Understand customer specifications and turn them into working products. Write API documentation using Markdown and JSON-Schema. Test APIs using Insomnia.

Tech Stack

Node.JS, Typescript, Javascript, ECMAScript 2020, REST API, MySQL, HAL, HTML5, CSS3, OAuth2.

Frontend Web Developer at ResortSuite Toronto, Canada, Apr/2018 – Nov/2019

ResortSuite is an enterprise grade integrated software application for the hospitality industry.


Working closely with the team to plan & design client custom web / mobile pages. Implemented designs for both web & mobile for clients. Applying new features & enhancement to the core web / mobile app for new version release. Develop mobile applications using the Cordova framework.

Tech Stack

Javascript, React, Cordova, MongoDB, SOAP API, HTML, CSS, Sketch.

Junior Web Developer at Maestro PMS Markham, Ontario, Nov/2017 – Apr/2018

Established, leading provider of Hotel and Resort Property Management Software Solutions to the Independent Full-Service Hospitality marketplace.


Wrote & designed group landing page templates & features within 30 days of being hired. Resulting in a reduction of 80% time needed for a common internal business process. Collaborated with the team of developers to manage large, complex projects for hotels & resorts. Maintained more than 200 websites across clients. Discussed options with clients to make sure websites meet their needs. Developed, maintained and tested clients hotel websites, booking emails, group booking page. Designed & Styled Maestro PMS Software.

Tech Stack

Javascript, HTML, CSS, SasS/SCSS, Adobe CS



English - Full Professional Proficiency Korean - Native or Bilingual Proficiency


Javascript/ECMA2020, TypeScript, NodeJS, HTTP, REST API/HAL, MySql, MongoDB, HandlebarsJS, HTML5/CSS3, LESS/SasS, OAuth2, Ubuntu, Ruby/Rails