Senior Software Developer – Full Stack (Java)
Posted Updated
Summary
Upstaff is hiring a Senior Full Stack Java Developer to work onsite (5 days/week) with the Ontario Public Service's Government Services Integration Cluster in Toronto. Day to day: building enterprise Java microservices, REST APIs, and Oracle-backed integrations secured with JWT/OAuth 2.0, delivered via Azure DevOps pipelines.
Position Overview
We are seeking an experienced Senior Software Developer – Full Stack (Java) to join the Government Services Integration Cluster (GSIC) within the Ontario Public Service. The successful candidate will design, develop, integrate, test, deploy, and maintain enterprise-scale web applications and reusable platform capabilities across frontend, backend, API, workflow, middleware, integration, and database layers.
The role requires extensive hands-on Java development experience, strong expertise in REST APIs and microservices, proficiency with Oracle and relational database technologies, and practical experience implementing secure application integrations using JSON Web Tokens (JWT), OAuth 2.0, SSL certificates, and secure communications protocols.
The successful candidate will translate technical specifications into secure, scalable, maintainable, and thoroughly tested applications while collaborating with architects, business analysts, UX designers, QA specialists, DevOps engineers, security and privacy teams, and ministry stakeholders. The candidate will also provide technical leadership, participate in code reviews and design walkthroughs, troubleshoot complex application issues, and support production releases and ongoing platform enhancements.
Key Responsibilities
- Design, develop, test, deploy, integrate, and maintain enterprise-grade, multi-client web applications and reusable platform services.
- Build and maintain Java-based applications, microservices, REST APIs, RESTful web services, and Internet-ready enterprise solutions.
- Develop full-stack application components across user interfaces, backend services, workflows, middleware, integrations, and data-access layers.
- Translate approved business requirements, technical specifications, and system designs into detailed programming specifications and working application code.
- Write, compile, debug, unit test, document, maintain, and optimize application code using object-oriented programming principles, established design patterns, refactoring techniques, and clean-code practices.
- Design and implement secure integrations with registries, permitting systems, forms, payment services, notifications, document management, identity services, and other enterprise platforms.
- Develop and maintain database objects, SQL queries, data-access components, data transformations, and conversion routines using Oracle and other relational or hierarchical database technologies.
- Perform SQL tuning, query optimization, data validation, data migration, and conversion activities to support application performance and data integrity.
- Implement security gateways and application security protocols, including JWT, OAuth 2.0, SSL certificates, identity integration, access controls, and secure communications.
- Apply microservice architecture principles to build extensible, maintainable, scalable, and resilient application components.
- Develop and maintain automated unit, integration, API, database, and user-interface tests to ensure application quality and reliability.
- Use Azure DevOps or comparable tools for work management, source control, build automation, testing, and deployment pipelines.
- Review and maintain build scripts, configuration files, product installation procedures, and deployment scripts; perform coding, testing, debugging, and troubleshooting as required.
- Participate in solution design discussions, technical design walkthroughs, impact assessments, code reviews, estimation, backlog refinement, sprint planning, and release planning.
- Collaborate with business stakeholders, subject-matter experts, architects, analysts, testers, UX designers, DevOps engineers, and security specialists to resolve technical and functional issues.
- Troubleshoot and resolve complex application issues arising during development, implementation, deployment, data conversion, migration, and production operations.
- Provide implementation, migration, conversion, post-implementation, and production support for enterprise applications.
- Identify opportunities to improve application performance, reliability, security, extensibility, and maintainability.
- Prepare and maintain technical specifications, system documentation, deployment instructions, support procedures, and other required project documentation.
- Provide technical guidance, contribute to engineering best practices, and support delivery commitments within an Agile development environment.
Mandatory Qualifications and Experience
Candidates must demonstrate the following essential qualifications:
- 10+ years of experience designing and developing large-scale, multi-client web applications or equivalent senior-level software development experience.
- Extensive hands-on experience in Java development, including enterprise application design, coding, debugging, testing, and maintenance.
- Strong experience working with Oracle, SQL, or comparable relational database technologies, including database objects, queries, data-access components, and SQL optimization.
- Significant hands-on experience designing and developing REST APIs and RESTful web services.
- Demonstrated experience with microservice architecture, reusable services, and scalable, maintainable enterprise application design.
- Experience developing and supporting Internet-ready applications using object-oriented programming, established design patterns, clean-code principles, refactoring, and structured software development methodologies.
- Hands-on experience implementing application security gateways and protocols, including JSON Web Tokens (JWT), OAuth 2.0, SSL certificates, secure communications, and identity integration.
- Experience translating technical system specifications into tested applications, including detailed programming specifications, code development, compilation, debugging, documentation, maintenance, and unit testing.
- Experience with relational and hierarchical databases, query languages, data-access components, SQL tuning, middleware, gateways, and enterprise communication protocols.
- Experience with data conversion, data migration, enterprise integrations, implementation support, and post-implementation troubleshooting.
- Experience using Azure DevOps or comparable tools for source control, work tracking, automated builds, testing, and deployment pipelines.
- Experience conducting technical design walkthroughs, code reviews, impact assessments, troubleshooting, and application maintenance.
- Ability to work onsite five days per week at 222 Jarvis Street, Toronto, for the duration of the assignment.
Technical Skills and Competencies
Programming and Application Development
- Java and enterprise application development
- Full-stack development and Internet-ready applications
- Object-oriented programming and design principles
- Design patterns, clean code, refactoring, debugging, and unit testing
- REST APIs, RESTful web services, and microservices
Database and Data Management
- Oracle and SQL or comparable relational databases
- Relational and hierarchical database technologies
- SQL query development, performance tuning, and optimization
- Data-access components, data transformation, conversion, and migration
Security and Enterprise Integration
- JWT and OAuth 2.0
- SSL certificates and secure communications
- Identity integration and security gateways
- Middleware, integration gateways, and communication protocols
- Enterprise service integration and reusable platform services
DevOps, Testing, and Delivery
- Azure DevOps or comparable development and delivery tools
- Source control, build automation, testing, and deployment pipelines
- Automated unit, integration, API, database, and UI testing
- Build and deployment scripts, configuration management, and troubleshooting
- Agile delivery and structured software development methodologies
Communication and Professional Skills
- Strong written and verbal communication, analytical thinking, and systematic problem-solving abilities.
- Effective collaboration with business and technical stakeholders across multidisciplinary teams.
- Ability to communicate technical concepts clearly and participate in design walkthroughs and technical decision-making.
- Strong organizational, interpersonal, decision-making, and negotiation skills.
- Ability to manage competing priorities, adapt to changing requirements, work under pressure, and meet aggressive delivery timelines.
- Commitment to software quality, secure development practices, technical documentation, and continuous improvement.
Requirements
Preferred Experience: Ontario Public Sector
Experience working within the Ontario Public Service or comparable public-sector environments is an asset, particularly familiarity with:
- Government application development standards, technical governance, and delivery processes.
- Public-sector security, privacy, accessibility, and information-management requirements.
- Enterprise documentation, release management, change control, and production support procedures.
Submission Requirements
Interested candidates should submit an updated resume demonstrating their relevant experience against the mandatory qualifications, particularly:
- 10+ years of large-scale, multi-client web application development experience.
- Extensive hands-on Java and Oracle/SQL or comparable relational database experience.
- Strong REST API, RESTful web services, and microservices development experience.
- Practical implementation experience with JWT, OAuth 2.0, SSL certificates, secure communications, and identity integration.
- Azure DevOps or comparable tooling, automated testing, enterprise integrations, and production support experience.
- Availability to work onsite five days per week at the Toronto office.