Senior Software Developer – Full Stack (Java)
Posted Updated
Summary
Upstaff is hiring a senior full-stack Java developer (10+ years) to build enterprise web applications and reusable platform services for Ontario's Government Services Integration Cluster. Work spans Java microservices, REST APIs, Oracle/SQL data layers, secure integrations (JWT, OAuth 2.0, SSL), and Azure DevOps pipelines for government programs.
Position Overview
We are seeking an experienced Senior Software Developer – Full Stack (Java) to design, develop, integrate, test, deploy, and maintain enterprise-grade web applications and reusable platform services for the Government Services Integration Cluster (GSIC).
The successful candidate will have 10+ years of senior-level software development experience, with strong hands-on expertise in Java, Oracle and SQL-based relational databases, REST APIs, RESTful web services, microservices architecture, and secure enterprise application development.
The role involves developing frontend and backend components, APIs, workflows, middleware, integrations, and data-access services to support multiple government programs. The developer will collaborate with solution architects, business analysts, product managers, UX designers, QA specialists, DevOps engineers, security and privacy teams, and ministry stakeholders to deliver secure, scalable, reliable, and maintainable applications.
Candidates must demonstrate practical experience implementing security protocols, including JSON Web Tokens (JWT), OAuth 2.0, SSL certificates, secure communications, and identity integration. The successful candidate will also contribute to technical design, code reviews, automated testing, troubleshooting, deployment, production support, and continuous improvement throughout the software development lifecycle.
Key Responsibilities
- Design, develop, test, deploy, and maintain enterprise-scale, multi-client web applications and reusable platform services.
- Develop and maintain Java-based applications, microservices, REST APIs, RESTful web services, frontend and backend components, workflows, and integration services.
- Translate approved business requirements, technical specifications, and architectural designs into secure, tested, production-ready software.
- Develop detailed programming specifications and perform coding, compilation, debugging, unit testing, documentation, and application maintenance.
- Design and implement secure APIs, authentication and authorization mechanisms, identity integrations, security gateways, and secure communications using JWT, OAuth 2.0, and SSL certificates.
- Design, develop, and maintain database objects, SQL queries, data-access components, data transformations, and conversion or migration routines using Oracle, SQL, and comparable relational database technologies.
- Apply object-oriented programming principles, design patterns, clean-code practices, refactoring, and microservices architecture to improve extensibility, scalability, and maintainability.
- Build and maintain enterprise integrations involving middleware, API gateways, communications protocols, registries, permitting, forms, payments, notifications, documents, identity, and other business-facing services.
- 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, release management, and deployment pipelines.
- Review, modify, test, and troubleshoot build scripts, configuration files, installation scripts, and deployment processes.
- Participate in technical design walkthroughs, architecture discussions, impact assessments, code reviews, estimation, backlog refinement, sprint planning, and release planning.
- Identify and resolve technical issues related to development, integration, implementation, conversion, migration, deployment, and production operations.
- Analyse application performance, troubleshoot database and integration issues, and implement improvements to reliability, scalability, security, and maintainability.
- Provide implementation, migration, conversion, post-implementation, and ongoing production support for complex enterprise applications.
- Collaborate with business and technical stakeholders to clarify requirements, document technical decisions, and ensure solutions align with approved standards and architecture.
- Prepare and maintain technical specifications, system documentation, deployment instructions, support procedures, and other required project documentation.
- Provide technical guidance, conduct knowledge sharing, and support development quality while meeting project deadlines and changing priorities.
- Ensure compliance with applicable government development standards, security requirements, accessibility expectations, information-management practices, and documentation procedures.
Mandatory Qualifications and Experience
1. Core Skills and Experience
- Minimum 10 years of experience designing and developing large-scale, multi-client web applications or equivalent senior software development experience.
- Extensive hands-on experience in Java application development with Oracle, SQL, or comparable relational database technologies.
- Significant experience designing, developing, and implementing REST APIs and RESTful web services.
- Demonstrated experience with microservices architecture and developing secure, scalable, Internet-ready applications.
- Proven ability to translate technical system specifications into working applications, including programming specifications, coding, compilation, debugging, documentation, maintenance, and unit testing.
- Strong understanding of object-oriented programming, design patterns, clean code, refactoring, structured development methodologies, and Agile delivery practices.
- Experience using Azure DevOps or comparable tools for source control, work tracking, automated builds, testing, and deployment pipelines.
2. Security and Technical Expertise
- Hands-on experience with security gateways and protocols, including:
- JSON Web Tokens (JWT).
- OAuth 2.0.
- SSL certificates.
- Secure communications.
- Authentication, authorization, and identity integration.
- Strong knowledge of relational and hierarchical database technologies, query languages, SQL tuning, and data-access components.
- Experience with middleware, API gateways, enterprise integrations, communications protocols, and data migration or conversion activities.
- Experience with application configuration, installation, deployment scripts, troubleshooting, and post-implementation support.
- Ability to create and maintain automated tests and participate in technical design reviews, code reviews, and impact assessments.
3. Communication and Collaboration
- Strong written and verbal communication, analytical thinking, systematic problem-solving, decision-making, interpersonal, and negotiation skills.
- Ability to explain technical concepts, develop and present ideas, and participate effectively in technical design walkthroughs.
- Demonstrated ability to work collaboratively with business stakeholders, subject-matter experts, architects, developers, testers, and other IT professionals.
- Ability to work under pressure, adapt to changing priorities, manage competing demands, and deliver high-quality results within aggressive timelines.
4. Public-Sector Experience
- Knowledge of Ontario Public Service (OPS) development standards, processes, governance, security, accessibility, information management, and documentation expectations.