Internship Full Stack Developer Jobs in Mississauga, ON

Build scalable SaaS solutions that make a real-world impact as a Senior Full Stack Developer (Node.js + React)

We're partnering with an established software company looking for a Senior Full Stack Developer to join a small, highly collaborative product team developing enterprise web applications used by organizations across the education, telecom and goverment sectors.

This role is ideal for someone who enjoys owning features from design through deployment. You'll work across the full stack using React on the frontend and Node.js on the backend, building REST APIs, integrating messaging services, designing microservices, and contributing to architectural decisions that shape the long-term direction of the platform.
???? Who You Are
You're a senior full stack developer who enjoys taking ownership of your work and building scalable, high-quality applications. You thrive in collaborative environments and bring a thoughtful approach to solving complex technical challenges.

You're someone who:

• Enjoys working across both the frontend and backend using Node.js and React
• Thinks beyond implementation and contributes to technical and architectural discussions
• Writes clean, maintainable, and well-documented code
• Takes ownership of features from design through deployment
• Communicates openly, asks thoughtful questions, and collaborates effectively with Product and Development teams
• Enjoys solving complex engineering problems and continuously improving the way software is built
• Keeps the end user in mind when designing technical solutions

???? 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 Node.js and React
• Build scalable backend services and RESTful APIs supporting modern SaaS applications
• Develop responsive, intuitive user interfaces using React and modern frontend development practices
• Design and implement solutions within a microservices architecture
• Develop integrations using RabbitMQ or similar messaging technologies
• Work with PostgreSQL and other relational databases to support scalable, high-performance applications
• Participate in application architecture, feature design, and technical planning discussions
• Translate user stories and product requirements into well-designed technical solutions
• Perform code reviews and contribute to development standards and best practices
• Troubleshoot complex issues across frontend, backend, APIs, messaging services, and databases
• Help establish and improve CI/CD pipelines using GitHub Actions, Jenkins, or similar tools
• Write clear technical documentation to support long-term maintainability
• Collaborate closely with Product to ensure solutions meet both technical and business requirements

⭐ What We're Looking For

• 6+ years of professional experience developing full stack web applications
• Strong commercial experience developing backend services with Node.js
• Extensive experience building modern frontend applications using React
• Strong understanding of JavaScript, asynchronous programming, and REST API development
• Experience working within a microservices architecture
• Hands-on experience with RabbitMQ, Kafka, or another messaging platform
• Experience with PostgreSQL, MySQL, MariaDB, or similar relational databases
• Experience contributing to CI/CD pipelines using GitHub Actions, Jenkins, or similar technologies
• Strong understanding of software architecture, scalable application design, and engineering best practices
• Experience working within Agile/Scrum development environments
• Excellent analytical, troubleshooting, and problem-solving skills
• Strong communication skills and the confidence to contribute to technical discussions
• Commitment to writing clean, maintainable, well-documented code

Nice-to-Haves

• PHP development experience
• Experience designing application architecture
• Docker or containerization experience
• Familiarity with Tailwind CSS or modern frontend tooling
• Experience working with AI-assisted development tools

???? What Makes This Role Exciting

• Own More Than Just Your Code: Play an active role in shaping technical solutions, contributing to architectural decisions, and influencing the direction of products from concept to deployment.
• Solve Interesting Engineering Challenges: Work across the full stack on scalable applications, distributed systems, and modern microservices that require thoughtful engineering, not just feature delivery.
• Join a Team Where Your Voice Matters: Work alongside a collaborative group of developers and Product leaders who value open communication, fresh ideas, and continuous improvement.
• Build Technology That Makes a Difference: Contribute to software that helps organizations create safer digital environments while delivering reliable, high-quality solutions to customers around the world.

Benefits

• Base Salary: $110,000 - $130,000
• Paid Time Off: Competitive vacation and personal days to help maintain a healthy work-life balance
• Health & Wellness Benefits: Medical, dental, and vision benefits to support your overall well-being
• Professional Development: Annual professional development allowance to support continued learning and technical 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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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.