Senior .NET Developer

About ALTEN: In just three decades, ALTEN has become a global leader in Research & Development, Engineering, IT Services, Life Sciences, and Network Services. With a presence in more than 30 countries and a team of over 60,000 employees, we are trusted by industry leaders worldwide to deliver pioneering solutions and drive technical excellence. ALTEN CANADA, a proud subsidiary of ALTEN headquartered in France, is dedicated to serving the Canadian market. With offices in Montreal and Toronto, we combine global expertise with local insight to accelerate innovation across Canada. At ALTEN CANADA, our consultants thrive on solving complex, highly technical challenges across diverse industries. From Life Sciences to Energy, Automation to Manufacturing, Aviation, Defense. Automotive, Rail and Transportation to Information Systems and Telecommunications, our unwavering commitment to excellence shaping the future of technology and industry. About the Opportunity We are seeking a Senior Backend Developer (.NET / Java) to support a large-scale application security remediation and modernization initiative across a portfolio of legacy enterprise applications. This role focuses on enhancing, securing, and modernizing approximately 10-15 backend applications currently running on legacy .NET technologies. The successful candidate will play a key role in vulnerability remediation, framework upgrades, dependency modernization, and application migration activities within a highly regulated financial services environment. This is an excellent opportunity for an experienced developer who enjoys solving complex technical challenges, modernizing legacy systems, and improving application security. What You'll Do Design, develop, and implement backend application changes using C#/.NET.Contribute to Java-based application enhancements and remediation efforts as needed.Analyze, troubleshoot, and remediate application security vulnerabilities.Upgrade frameworks, libraries, and third-party dependencies from legacy environments to modern supported versions.Refactor and modernize existing codebases to improve maintainability, performance, and security.Maintain and enhance integrations with Oracle databases.Perform code reviews and ensure adherence to development and security best practices.Develop and execute unit tests to validate application functionality and stability.Create and maintain technical documentation.Collaborate with developers, architects, QA teams, and stakeholders to prioritize and deliver project objectives.Support troubleshooting and issue resolution across multiple applications. Required Qualifications 7+ years of software development experience.Strong hands-on experience with C# and .NET backend development.Strong experience with Java development.Proven experience modernizing or migrating legacy enterprise applications.Experience working within financial services, banking, wealth management, investment management, insurance, or another highly regulated industry.Experience with relational databases, including Oracle.Strong understanding of software development best practices, testing, and code quality standards. Nice to Have Experience with application security remediation and vulnerability mitigation.Familiarity with secure coding practices and security scanning tools.Experience with framework, dependency, and platform upgrades.Knowledge of modern software architectures and modernization initiatives.Experience supporting enterprise-scale application portfolios. Technical Environment Core Technologies C#.NET Framework / .NETJavaOracle Database Key Focus Areas Legacy Application ModernizationSecurity Vulnerability RemediationDependency and Framework UpgradesBackend DevelopmentApplication MigrationUnit Testing & Code Reviews ALTEN Canada fosters a dynamic, collaborative work environment where every team member is empowered to reach their full potential. We are deeply committed to investing in our people by offering meaningful experiences and supporting continuous learning, growth, and career development At ALTEN Canada, your skills are celebrated, your ambitions supported, and your growth continuously nurtured. Join us and discover the difference of working with a company that values innovation, collaboration, and excellence, where endless possibilities await. ALTEN CANADA is committed to promoting diversity, equity, and inclusion. We strive to provide a work environment where every individual feels welcomed, valued, and respected, allowing them to thrive to their full potential. This includes our dedication to offer accessibility measures to those who require them. Should you require any accommodation during our recruitment process, please reach out to us. Alten uses artificial intelligence tools to support certain administrative aspects of the recruitment process, such as interview note-taking and résumé formatting. These tools do not make hiring decisions. Candidate consent is always obtained prior to use. In accordance with our compensation practices, ALTEN is providing the salary range associated with this opportunity. Final compensation will be determined after considering several factors, including professional experience, skill set, educational background, certifications, and geographic market conditions. The current target salary range for this role is $115k/Annum This job posting corresponds to an active and immediate vacancy currently open with one of Alten’s clients.