senior software developer - full stack.

We are seeking an accomplished Senior Software Developer - Full Stack to design, build, and optimize scalable, end-to-end web applications and high-performance microservices. In this role, you will bridge modern front-end interfaces with complex multi-language back-end services, leveraging Next.js/React on the front end alongside Python (FastAPI) and .NET Core (C#) on the back end. Operating across cloud-native architectures, relational/NoSQL databases, and automated CI/CD pipelines, you will lead solution design, build reusable components, engineer RESTful APIs, and establish software development standards in a fast-paced Agile environment.

Location: Toronto, ON (Fully Onsite – 5 days/week required)

Duration: 7-month contract.

Advantages
Cutting-Edge Stack: Drive full-stack initiatives across React/Next.js, FastAPI (Python), .NET Core (C#), and Azure.

High Technical Ownership: Direct architectural decisions across microservices, serverless frameworks, and UI components.

Advanced Technology Integration: Work in an environment exploring computer vision and machine learning integrations.

Structured Onsite Synergy: Collaborate directly with senior developers and technical leads in a 5-day onsite workspace.

Responsibilities
Full-Stack Application Engineering: Architect, build, and maintain responsive front-end interfaces using Next.js, React.js, and Node.js while developing robust back-end microservices using Python (FastAPI) and .NET Core (C#).

API Design & Integration: Design, construct, and secure RESTful APIs and Web API services, integrating front-end user interactions seamlessly with underlying data layers.

Database & Cloud Management: Optimize database architecture, stored procedures, triggers, and query performance using Azure SQL Server, Cosmos DB, and Redis caching.

Data Pipeline Development: Design and continuously expand automated data extraction, transformation, and loading (ETL) pipelines to process application datasets.

Security & Authentication Implementation: Enforce application security standards, OAuth 2.0 protocols, JWT authentication, session management, and secure key storage using Azure Key Vault.

Architecture & Component Design: Participate in end-to-end solution architecture design, building testable UI architectures, serverless components, and reusable UI/UX design patterns.

DevOps & Container Deployment: Manage CI/CD automation pipelines, application packaging, and containerized deployments using Azure DevOps tools.

Testing, Technical Support & Mentorship: Conduct unit testing, debug complex technical issues during migration and deployment phases, and mentor junior team members to foster technical excellence.

Qualifications
React & Next.js Mastery: Advanced, hands-on proficiency developing web applications using Next.js, React.js, and Node.js (Strictly Required).

Python & FastAPI Expertise: Strong proficiency in modern Python development with a proven track record of designing and building RESTful APIs using FastAPI (Strictly Required).

.NET Core & C# Seniority: Proven expertise architecting and developing .NET Core Services, Web APIs, and backend logic using C# (Strictly Required).

Testable UI & Responsive Architecture: Advanced knowledge of UI design, responsive design patterns, and testable front-end software architecture (Strictly Required).

Azure Database Engineering: Expert-level experience with MS Azure SQL Server, including stored procedures, query optimization, encryption, and database tuning (Strictly Required).

Security & Auth Protocols: Demonstrated experience implementing OAuth 2.0, JWT authentication, Web Security, and session management.

DevOps & Cloud Tools: Hands-on working knowledge of Azure DevOps pipelines, containerized deployments, and cloud platform services.

Nice to Have:
3+ years of experience working with machine learning models, specifically in computer vision (e.g., OpenCV, PyTorch, TensorFlow).

Summary
If you're interested in the "Senior Software Developer - Full Stack" role based in Toronto, we encourage you to apply online at
Only qualified candidates will be contacted for the next steps. We look forward to hearing from you!

Randstad Canada is committed to fostering a workforce reflective of all peoples of Canada. As a result, we are committed to developing and implementing strategies to increase the equity, diversity and inclusion within the workplace by examining our internal policies, practices, and systems throughout the entire lifecycle of our workforce, including its recruitment, retention and advancement for all employees. In addition to our deep commitment to respecting human rights, we are dedicated to positive actions to affect change to ensure everyone has full participation in the workforce free from any barriers, systemic or otherwise, especially equity-seeking groups who are usually underrepresented in Canada's workforce, including those who identify as women or non-binary/gender non-conforming; Indigenous or Aboriginal Peoples; persons with disabilities (visible or invisible) and; members of visible minorities, racialized groups and the LGBTQ2+ community.

Randstad Canada is committed to creating and maintaining an inclusive and accessible workplace for all its candidates and employees by supporting their accessibility and accommodation needs throughout the employment lifecycle. We ask that all job applications please identify any accommodation requirements by sending an email to View email address on randstad.com to ensure their ability to fully participate in the interview process.

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