Senior .NET Developer – Application Security

As a Senior .NET Developer, you will make an impact by strengthening the security posture of enterprise applications through vulnerability analysis, remediation, and secure software development practices. In this role, you will bridge software engineering and enterprise security by analyzing SAST/DAST/SCA scan results, performing root-cause analysis on vulnerabilities, and directly writing and deploying secure .NET code fixes. Leveraging modern DevSecOps practices and AI-assisted engineering tools (such as GitHub Copilot and Claude), you will accelerate vulnerability remediation and enforce secure coding standards across production pipelines.

In this role, you will

• Analyze and remediate application security vulnerabilities identified through SAST, DAST, SCA, and penetration testing assessments.
• Implement secure coding practices across .NET applications in alignment with OWASP standards and industry best practices.
• Review, investigate, and resolve security findings generated by tools such as Checkmarx, Fortify, AppScan, SonarQube, and similar platforms to evaluate risk and validate security patches.
• Perform root cause analysis of security issues and implement sustainable remediation strategies to prevent recurrence.
• Collaborate with development, architecture, DevOps, and security teams to ensure timely resolution of identified vulnerabilities.
• Support Secure SDLC initiatives and ensure compliance with organizational and client application security requirements.
• Conduct code reviews with a strong focus on security, maintainability, and application performance.
• Integrate automated security gates into CI/CD pipelines and utilize AI-driven tools (GitHub Copilot, Claude) to accelerate code reviews, threat analysis, and remediation workflows.
• Provide technical guidance and mentorship on secure development practices and vulnerability prevention.

Work model:

We strive to provide flexibility wherever possible. Based on this role’s business requirements, this is a remote position open to qualified applicants in Canada. Regardless of your working arrangement, we are here to support a healthy work-life balance through our various wellbeing programs.

Note: The working arrangements for this role are accurate as of the date of posting. This may change based on the project you’re engaged in, as well as business and client requirements. Rest assured; we will always be clear about role expectations.

What you need to have to be considered:

• 6+ years of strong .NET development background with proven experience in identifying and fixing application vulnerabilities.
• Must have strong hands-on experience in vulnerability remediation and security fixes for internet-facing applications.
• Hands-on experience with DAST, SAST, and SCA tools such as AppScan, Checkmarx, SonarQube, or equivalent.
• Demonstrated experience remediating OWASP Top 10 vulnerabilities, security findings, and secure coding issues in production applications.
• Experience supporting and securing internet-facing web applications, APIs, and cloud-hosted services.
• Ability to independently analyze scan reports, perform root-cause analysis, and implement remediation with minimal ramp-up.
• Familiarity with CI/CD security integration and DevSecOps practices.
• Experience leveraging AI-assisted development and security tools (GitHub Copilot, Claude similar) to accelerate vulnerability analysis, code remediation, secure code reviews, and developer productivity.
• Strong communication skills and ability to work directly with client stakeholders.

We're excited to meet people who share our mission and can make an impact in a variety of ways. Don't hesitate to apply, even if you only meet the minimum requirements listed. Think about your transferable experiences and unique skills that make you stand out as someone who can bring new and exciting things to this role.

Total compensation:

We regularly assess market data to ensure we offer a competitive compensation package for our associates. The base salary for this position ranges between CAD 70,000 - 93,000 per year. Where the successful candidate may fall within the range depends on relevant education, work and/or management experience and other business-related and job-necessary qualifications. This position is also eligible for Cognizant’s discretionary annual performance-based bonus, as well as benefits that support your physical, mental and financial wellbeing.