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Senior Developer

Calgary

As a key member of our development team, you will independently design and implement solutions for JIRA tickets, rigorously test your work across environments, and actively contribute to stand-ups and day-to-day delivery. You’ll support troubleshooting efforts, review and approve pull requests, and drive code quality through enhancement and refactoring ideas shared with our Tech Leads. You will also lead smaller projects with support from technical leadership and contribute to interviewing, onboarding, and mentoring to help grow the wider team. If you’re ready to lead front-end development on our existing projects, elevate code quality, and help grow the team’s skills, we’d love to hear from you.

Our new hires & employees are the future of our organization, and we want to set you up for long-term success. In an effort to do so, we expect our team to work from an office a minimum of 3 days a week.

You will:

  • Lead the design, development, and maintenance of web applications using HTML, CSS, and JavaScript (ES6+).
  • Own front-end architecture and implementation decisions, ensuring code is scalable, maintainable, and consistent across projects.
  • Turn UI/UX designs and wireframes into accessible, responsive, and cross-browser compatible web interfaces.
  • Collaborate closely with designers, back-end developers, project managers, and other stakeholders to shape requirements and deliver high-quality features.
  • Conduct thorough code reviews, providing constructive feedback and helping to maintain coding standards and best practices.
  • Mentor and support intermediate and junior developers, guiding them on technical approaches, patterns, and problem-solving.
  • Proactively identify and resolve performance issues, improving load times, responsiveness, and overall usability.
  • Debug and troubleshoot complex front-end issues.
  • Promote and maintain clean, well-documented code, and ensure project documentation is complete and up to date in line with platform guidelines.
  • Stay current with front-end technologies and best practices - and help evaluate and introduce new tools/approaches where they add value.

You have:

  • 5+ years of professional front-end development experience, including work on complex or large-scale web applications.
  • Expert-level proficiency in vanilla JavaScript (ES6+)
  • Strong, hands-on experience with HTML5 and CSS3, including pre-processors such as SASS/SCSS.
  • Deep understanding of responsive design, cross-browser compatibility, and mobile-first development.
  • Proven experience designing or working within scalable front-end architectures and patterns (modular components, separation of concerns, reuse).
  • Solid experience with Git and modern collaborative workflows (pull requests, branching strategies, code reviews).
  • Demonstrated ability to take ownership of features from concept through to deployment and support.
  • Excellent communication and collaboration skills, with the ability to work effectively across disciplines.
  • Experience guiding or mentoring other developers and contributing to a positive, learning-focused team culture.

You may have:

  • Experience using jQuery for DOM manipulation and event handling, particularly in maintaining or modernizing existing codebases.
  • Strong experience integrating with REST APIs, including error handling, state management, and data flow on the front end.
  • Familiarity with SEO-related front-end practices (semantic HTML, performance, metadata, structured content).
  • Hands-on experience with front-end build tools such as Webpack, Gulp, Grunt, or similar (configuration, optimization, troubleshooting).
  • Knowledge of front-end performance optimization techniques, such as bundling, code splitting, minification, and asset optimization.

What we offer:

  • Global maternity and parental leave
  • Competitive benefits packages
  • Vacation, compassionate leave, personal/sick days, and flex days
  • Access to online services for families and new parents
  • Early Dismissal Friday’s (off at 3:00 PM local time every Friday)
  • 13 affinity groups
  • Internal learning and development programs
  • Enterprise-wide employee discounts

Critical Mass is an equal opportunity employer. 

The Critical Mass Talent Acquisition team will only communicate from email addresses that use the URLs criticalmass.com, omc.com and us.greenhouse-mail.io. We will not use apps such as Facebook Messenger, WhatsApp, or Google Hangouts for communicating with you. We will never ask you to send us money, technology, or anything else to work for our company. If you believe you are the victim of a scam, please review your local government consumer protections guidance and reach out to them directly.

If U.S. based: https://www.consumer.ftc.gov/articles/job-scams#avoid
If Canada based: https://www.canada.ca/en/services/finance/consumer-affairs.html
If U.K. based: https://www.gov.uk/consumer-protection-rights
If Costa Rica based: https://www.consumo.go.cr/educacion_consumidor/consejos_practicos.aspx 

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DE&I Questionnaire

Voluntary Self-Identification

At Critical Mass, we are dedicated and determined to build a workforce that reflects the diversity of the communities in which we live and work. It is crucial that every team member can thrive and reach their full potential.

With that said, we’d like to know a little more about you. We ask all applicants to fill out the below voluntary self-identification questions in order to evaluate and improve our recruitment and diversity efforts. Answering is completely voluntary and will not affect the outcome of your application.

The data collected may be reviewed by the Critical Mass Talent Acquisition Team, Human Resources, our Diversity, Equality and Inclusion team, and our executives, but they will neither be reviewed by nor disclosed to anyone else. All the information that you share with us pursuant to this survey will be stored on our secure network servers located within Canada and the United States.  We will only retain this information so long as it is necessary for the purpose that we have described here or as may be required by applicable laws. Thereafter, we will either anonymize the information or delete it entirely.  If you elect to complete this survey, and at any point in the future you wish to retract or amend your responses, or otherwise have any questions about your data, you may contact our Talent Acquisition team at accommodations@criticalmass.com.

As set forth in Critical Mass’s Equal Employment Opportunity policy, we do not discriminate on the basis of any protected group status under any applicable law.

Aboriginal Peoples Definition:

Aboriginal Peoples means persons who are defined as: Indians (more commonly referred to as First Nations), Inuit, or Métis.

Members of Visible Minorities Definition:

Members of Visible Minorities means persons, other than Aboriginal people, who are non-Caucasian in race or non-white in color.
Examples:
Black (e.g. African, Caribbean, Other)
Arab (e.g. Middle Eastern, North African, etc.) 
Asian and Southeast Asian (e.g. Chinese, Japanese, Korean, Vietnamese, Cambodian, Laotian, Thais, etc.) 
West Asian (e.g. Armenian, Iranian, Persian, Egyptian, Turkish, etc.)
Other (e.g. Latin American, Pacific Islander, etc.) 

Persons with Disabilities Definition:

Persons with Disabilities means persons who have a physical or mental impairment or medical condition that substantially limits a major life activity, or if you have a history or record of such an impairment or medical condition.

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