Senior Full Stack Java Developer Jobs in Mississauga, ON

Build and Modernize Enterprise Web Applications as a Senior Full Stack Developer (PHP & React)
We're partnering with an established software company seeking a Senior Full Stack Developer to help enhance and evolve enterprise web applications used within the education sector.

Working as part of a collaborative product team, you'll contribute to the continued development of a mature application while helping introduce new features, modern APIs, and scalable integrations. This role combines hands-on development with technical problem-solving, giving you the opportunity to influence application architecture while modernizing an established platform for future growth.

If you enjoy improving existing systems, building thoughtful solutions, and working across the full technology stack, this is an opportunity to make a meaningful technical impact.

Who You Are

You are an experienced Full Stack Developer with strong expertise in PHP and React, and you enjoy building scalable web applications that are reliable, maintainable, and built to evolve.

You take ownership of your work, enjoy solving complex technical challenges, and aren't afraid to contribute to architectural discussions or suggest better ways of doing things. Whether you're building new features or modernizing existing functionality, you focus on writing quality code that delivers long-term value.

You thrive in a collaborative environment where communication, accountability, and continuous improvement are just as important as technical expertise.

Work Type

• Location: Waterloo, ON
• Hybrid: 2-3 days per week in the office
• Vacancy Type: This position reflects a new vacancy

Requirements

What You'll Do

• Design, develop, and maintain enterprise web applications using PHP and React
• Build and enhance RESTful APIs and backend services supporting modern web applications
• Develop responsive, user-friendly interfaces with React and modern frontend technologies
• Modernize existing application components by introducing scalable integrations and improving system architecture
• Work with MariaDB, MySQL, and related backend technologies to deliver reliable, high-performing applications
• Collaborate with Product to translate business requirements into practical technical solutions
• Participate in application architecture, feature design, and technical planning discussions
• Perform code reviews, troubleshoot complex application issues, and promote clean, maintainable code
• Contribute to CI/CD improvements, development standards, and technical documentation

What We're Looking For

• 6+ years of professional Full Stack development experience, with strong commercial expertise in PHP and React
• Experience designing and developing scalable web applications, RESTful APIs, and enterprise software solutions
• Strong understanding of relational databases, including MariaDB, MySQL, or similar technologies
• Experience working with modern software architecture and distributed application design
• Familiarity with Git, CI/CD pipelines, and Agile development methodologies
• The ability to translate business requirements into practical, well-designed technical solutions
• Strong analytical, troubleshooting, and problem-solving skills
• Excellent communication skills with the ability to collaborate across technical and non-technical teams
• A proactive mindset with a strong sense of ownership, accountability, and attention to detail

Nice-to-Haves

• Experience designing software architecture and contributing to technical solution design
• Node.js development experience or exposure to modern JavaScript backend frameworks
• Experience with Docker, virtual machines, or containerized development environments
• Familiarity with modern frontend tooling, including Tailwind CSS or Figma
• Experience implementing or improving CI/CD pipelines within a development team

What Makes This Role Exciting

• Modernize an Established Platform: Play a key role in evolving an existing enterprise application by introducing modern development practices, scalable APIs, and thoughtful technical improvements.
• Own the Full Development Lifecycle: From shaping technical solutions to delivering production-ready features, you'll have the opportunity to influence how software is designed, built, and maintained.
• Collaborate in a Small, High-Impact Team: Work closely with Product and Engineering in an environment where your ideas are heard, your expertise is valued, and your contributions have a visible impact.
• Build Software with Purpose: Help deliver reliable enterprise applications that support organizations in creating safer digital environments while solving meaningful technical challenges.

Benefits

• Base Salary: $110,000-$130,000
• Paid Time Off: Competitive vacation package with additional time awarded based on tenure.
• Health & Wellness: Comprehensive health, dental, and vision coverage from Day One, plus a Healthcare Spending Account.
• Professional Development: Annual professional development allowance to support continued learning and career growth.

 Ready to Elevate Your Career? Apply Now!   

At STACK IT Recruitment, we connect top talent with standout opportunities. If you meet at least 70% of the qualifications, we encourage you to apply for it. We'd love to chat!   

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 We're proud to support diversity and inclusion. Need accommodation during the hiring process? Just let us know; we are here to support you!  

AI Use Disclosure:   

STACK IT uses AI-enhanced tools to support initial candidate screening and interview note analysis. All assessments and hiring decisions remain human-led.