Senior Full Stack Developer

Hiring: Senior Full Stack Developer Location: Toronto, Ontario, Hybrid (3 days per week in office) Duration: October 19, 2026 – October 4, 2027 (possibility to extend) Hourly Rate: $80/hour - $100/hour (based on experience) Client: Public Sector - Healthcare Responsibilities: Design, develop, test, deploy, and maintain enterprise applications using .NET, AngularJS, JavaScript, and related technologies. Develop and integrate secure REST APIs and modernize legacy .NET Framework, WCF, Windows Services, and Windows Forms applications. Build responsive web user interfaces and implement secure authentication using JWT/OAuth2. Develop high-performance, multithreaded, and asynchronous applications. Develop, configure, and support Azure cloud services, including App Services, Azure SQL, Storage, Event Hub, ADX, Key Vault, and monitoring solutions. Develop and optimize SQL Server databases, including complex queries, stored procedures, indexing, execution plans, and performance tuning. Perform application testing, production troubleshooting, root-cause analysis, and performance optimization across application, database, cloud, and infrastructure layers. Support DevOps and CI/CD processes using Azure DevOps and Git-based source control. Conduct code reviews and ensure high-quality, maintainable, secure, and well-documented software. Collaborate with architects, analysts, QA, infrastructure teams, and business stakeholders on technical design and solution delivery. Contribute to application modernization and migration of legacy systems to modern Azure-based platforms. Deliverables include, but are not limited to: Develop functionalities per business requirements.Migrate applications from .NET Framework 4.x to .NET Core/.NET.Design, develop, and implement secure RESTful APIs.Develop modern Angular web front-ends and migrate existing AngularJS applications to Angular.Develop and optimize data access and database operations, including query and performance optimization.Conduct performance testing and tuning to improve application scalability, responsiveness, and reliability.Implement and enhance application security, including authentication, authorization, and secure API practices. Must Haves: Modernization & Legacy Transformation Experience: Demonstrated experience decomposing monolithic applications into modular services, APIs, or microservices. Experience developing modernization roadmaps and executing phased migrations with minimal business disruption. .NET Core / Backend Engineering Expertise: Advanced expertise in ASP.NET Core, REST API development, dependency injection, authentication/authorization, performance optimization, and enterprise application architecture. Angular Front-End Development Expertise: Experience designing and developing Angular applications, component-based architecture, state management, responsive UI design, and integration with REST services. Solution Architecture & Design Skills: Ability to design scalable, maintainable, secure, and loosely coupled solutions. Experience with DDD, API-first design, event-driven architecture, integration patterns, and modular architecture. Additional Qualifications and Experience: C# / .NET Development10+ years of hands-on experience developing enterprise applications using C#, .NET Core/ASP.NET Core, and ASP.NET Framework 3.5/4.x, including modernization of legacy .NET applications. REST API Development & SecurityStrong experience designing, developing, integrating, and troubleshooting RESTful APIs, including JWT, OAuth2, authentication, and authorization. Angular / Front-End DevelopmentStrong experience with AngularJS, JavaScript, HTML, CSS, jQuery, and ASP.NET MVC, with experience migrating legacy AngularJS applications to modern Angular preferred. Microsoft SQL Server & Database DevelopmentStrong T-SQL development skills, including stored procedures, views, triggers, indexing, query optimization, execution plans, and database performance tuning. Microsoft Azure Cloud Development Hands-on experience with Azure App Service, Azure SQL Managed Instance, Azure Storage, Event Hub, Azure Data Explorer (ADX), Key Vault, Application Insights, and Azure Monitor. Azure DevOps & GitExperience with Azure DevOps, CI/CD pipelines, automated deployments, release management, GitHub, and/or Azure Repos. Performance, Multithreading & ScalabilityStrong experience with multithreaded and asynchronous programming, parallel processing, application performance optimization, and scalability across application and database layers. Production Troubleshooting & TestingStrong troubleshooting and root-cause analysis skills using KQL, Postman, SoapUI, Swagger/OpenAPI, IIS, application logs, monitoring tools, and database diagnostics.Legacy Application ModernizationExperience maintaining and modernizing ASP.NET Framework, Windows Services, WCF/Web Services, Windows Forms, and IIS-hosted applications; Tomcat troubleshooting is anasset. Software Engineering & ArchitectureStrong knowledge of object-oriented programming, design patterns, software architecture, SDLC, Agile/Scrum, code reviews, clean code, and secure/maintainable software development practices. Desired Skills: Healthcare System Integration: Experience developing and supporting integrations between healthcare applications and systems.HL7: Familiarity with HL7 standards and healthcare messaging, including experience troubleshooting HL7 interfaces.FHIR: Knowledge of FHIR standards, resources, APIs, and modern healthcare interoperability.Mirth Connect: Hands-on experience developing, configuring, monitoring, and troubleshooting Mirth Connect channels and integrations. We appreciate all interest; however, only candidates whose experience fully meets the posted requirements will be considered. Interested? If you meet the above criteria apply now! **AI is not being used in the application/recruitment process for this position**