Senior Software Developer - API

We are seeking an experienced Senior Software Developer - API to design, build, and deploy high-performance RESTful API platforms, cloud services, and AI-driven applications. In this role, you will bridge modern web development with advanced artificial intelligence frameworks, leveraging React, Node.js, Next.js, and Agentic AI architectures. Working in an Agile environment, you will translate complex technical specifications into clean, scalable code, optimize frontend user interfaces, engineer data orchestration pipelines, and ensure seamless system integrations across enterprise cloud platforms.

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

Duration: 12-month contract.



Advantages
Cutting-Edge Tech Stack: Hands-on development with Agentic AI, LLMs, LangChain, RAG, and modern web frameworks.

Full-Stack & API Scope: Own end-to-end delivery from React/Next.js interfaces to RESTful API gateways and Azure cloud pipelines.

AI & Data Engineering: Build enterprise ML workflows using PySpark, Airflow, TensorFlow, and vector databases.

Dedicated Onsite Synergy: Collaborate directly with engineering teams in a structured, 5-day onsite workspace.



Responsibilities
Translate complex system specifications into clean, tested, and maintainable web applications and RESTful API platforms.

Architect, develop, and test robust RESTful APIs using Node.js, Next.js, and cloud API management tools.

Design and implement interactive, responsive frontend features and Progressive Web Apps (PWAs) using React, TypeScript, HTML, CSS, and modern web frameworks.

Develop agentic AI systems, multi-agent frameworks, and retrieval-augmented generation (RAG) pipelines using Python, LangChain, LangGraph, Qdrant, and LLMops workflows.

Build and integrate machine learning models and data orchestration workflows using XGBoost, TensorFlow, Airflow, and PySpark.

Secure and govern API layers, managing custom analytics, caching, logging, request/response transformations, and authentication protocols (OAuth2, JWT, Azure AD B2C).

Troubleshoot, debug, and resolve technical defects across development, testing, conversion, and production deployment phases.

Conduct unit testing, code reviews, and technical design walkthroughs while producing detailed documentation using tools like Swagger and YAML.



Qualifications
Frontend & Full-Stack Mastery: 5+ years of hands-on experience with the React framework, TypeScript, Node.js, Next.js, HTML, CSS, and Progressive Web Apps (PWAs) (Strictly Required).

RESTful API Engineering: 5+ years of experience designing, building, testing, and documenting RESTful APIs and integration gateways (Strictly Required).

Agentic AI & LLM Ecosystem: 2–3+ years of specialized experience with Multi-agent frameworks (Agentic AI), LLMops, MCP, LangChain, LangGraph, RAG, Qdrant vector database, and Python (Strictly Required).

Machine Learning & Big Data: Practical experience developing ML models (XGBoost, TensorFlow) and managing data workflows using Airflow and PySpark (Strictly Required).

Cloud Platform Proficiency: Direct hands-on experience building, deploying, and managing enterprise solutions on cloud platforms such as Azure (Strictly Required).

Nice-to-Have Assets:
Hands-on experience developing production-level AI agents and MLOps tools (MLflow, DVC).

Prior experience in public sector software delivery environments.



Summary
If you're interested in the "Senior Software Developer - API" role based in Toronto, we encourage you to apply online at www.randstad.ca.
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 accessibility@randstad.ca to ensure their ability to fully participate in the interview process.