Upstaff - Senior Full Stack Software Developer

Full Stack Developer is needed in Toronto, Canada.

Client: Upstaff

Location: Canada > Toronto, ON, ca

Contract: Contract

Job Description

Our client is seeking an experienced Senior Full Stack Software Developer to design, develop, test, implement, and maintain large-scale, multi-client web applications. The successful candidate will bring extensive experience in Java development, modern front-end technologies, RESTful services, database technologies, application architecture, and secure software development practices. This role requires a highly skilled professional capable of working across the full technology stack while collaborating closely with business stakeholders, architects, technical teams, and other project members throughout the Software Development Life Cycle (SDLC).

Requirements

Mandatory Skills and Experience

Core Development Experience

• 10+ years of experience as a designer and developer working on large-scale, multi-client web applications.
• 10+ years of hands-on Java development experience with Oracle and/or SQL databases.
• 5+ years of hands-on experience developing REST APIs and RESTful Web Services.
• Strong experience in programming, analysis, application design, development, testing, debugging, and documentation.
• Experience with object-oriented programming principles, design patterns, refactoring, and clean code practices.
• Experience working with structured methodologies for application design, development, implementation, and maintenance.
• Strong experience with relational and hierarchical database technologies.
• Strong SQL and database development skills, including Oracle and SQL Server.

Full Stack Development

• Proficiency in both front-end and back-end development.
• Experience with database design and management and DevOps practices.
• Strong knowledge of overall web architecture design and implementation.
• Experience designing and implementing scalable, high-performance web applications.
• Experience designing and constructing REST API services.
• Experience integrating front-end user interfaces with backend APIs.
• Experience designing and implementing Continuous Integration and Continuous Deployment processes.
• Experience developing responsive web applications.
• Experience ensuring front-end applications can query and consume APIs.

Java and Application Server Technologies

• Extensive hands-on experience with Java development for web applications.
• Experience with Java WebLogic, Tomcat, EJB, and Servlets.
• Experience developing and supporting server-side and client-side web application functionality.

Front-End Technologies

• Strong hands-on experience with React, TypeScript, JavaScript, HTML5, CSS3, and NodeJS.
• High-level knowledge and experience with Angular and AngularJS.
• Experience with RXJS, NextJS, and VueJS.
• Experience creating reusable, self-contained, and testable modules and components.
• Experience designing user interactions and interfaces for web applications.
• Fundamental understanding of UX/UI principles.

API and Integration Technologies

• Strong knowledge and experience with REST APIs and RESTful Web Services.
• Experience with front-end and back-end integration.
• Experience with middleware and gateways.

Security

• Knowledge of security gateways and protocols, including JWT, OAuth 2.0, and SSL Certificates.
• Understanding of secure application development practices.

Architecture and Design

• Strong knowledge of microservices architecture.
• Experience with application architecture, deployment, and troubleshooting.
• Experience designing applications for speed, scalability, and maintainability.

DevOps and Delivery Methodologies

• Experience using Azure DevOps and JIRA.
• Solid understanding of Agile and Scrum methodologies.

Accessibility and Standards

• Proven experience with WCAG accessibility standards.
• Knowledge of the Accessibility for Ontarians with Disabilities Act (AODA).

Additional Technical Knowledge

• Knowledge and experience with programming Internet-ready applications.
• Experience with Rapid Application Development (RAD) methodologies.

Soft Skills

• Excellent written and verbal communication skills.
• Strong analytical, problem-solving, and decision-making abilities.
• Proven systematic problem-solving skills.

Preferred / Nice-to-Have Skills

• Experience with OPS Development Standards and Processes.
• Public sector or Ontario Public Service experience.

Additional Information

Location: Toronto, Ontario

Work Arrangement: Hybrid – 5 Days Onsite

Contract Duration: September 21, 2026 – October 1, 2027

Extension: 1 possible extension

Allocation: 100%

Number of Openings: 1

Security Clearance: No Clearance Required

Important: Candidates must clearly demonstrate the mandatory experience in large-scale multi-client web application development, Java with Oracle/SQL databases, REST APIs/RESTful Web Services, and security protocols including JWT, OAuth 2.0, and SSL Certificates.