Cybersecurity Consulting Firm – Cyber Castellum
Modern applications are at the heart of business operations and a primary target for cyberattacks. Our expert-led Application Security Services provide strategic consulting to strengthen your security posture across every stage of the Software Development Lifecycle (SDLC).
Cyber threats are evolving faster than traditional application security approaches. Delayed testing or reactive fixes leave critical gaps that attackers exploit. We help organizations embed security into their development pipelines enabling early detection, mitigation, and compliance without slowing innovation.
Our consulting team specializes in designing “shift-left” security strategies and implementing robust practices like threat modeling, secure code reviews, and DevSecOps integration. Whether you are modernizing legacy applications or securing cloud-native platforms, we deliver actionable insights that reduce risks and operational costs.
With Cyber Castellum, you gain access to industry-leading expertise in application security:
Embed security early in the SDLC to reduce risks and costs.
Expert analysis of source code to uncover vulnerabilities and recommend fixes.
Prepare applications to meet industry regulations and pass audits confidently.
Proactively assess application architectures to identify potential attack vectors.
Evaluate and secure applications built by vendors or external teams.
Align security with CI/CD pipelines to enable rapid and secure deployments.
A NYS Government Agency was in the middle of a multi-year effort to replace a legacy mainframe system serving hundreds of thousands of members, employers, and beneficiaries with a new, modern web application.
A NYS Government Agency was in the middle of a multi-year effort to replace a legacy mainframe system serving hundreds of thousands of members, employers, and beneficiaries with a new, modern web application.
The system was rolled out in phases, each adding significant new functionality, from self-service registration through benefit calculation, enrollment, and payment processing.
With that much surface area changing continuously, security testing couldn't be a one-time, end-of-project checkbox. It had to move at the same pace as development, or risk becoming the bottleneck that delayed a critical modernization program relied on by the public.
Security testing needed to move with the software development lifecycle — not wait for the project to finish.
Cyber Castellum was brought in as the embedded application security testing partner for the program, structuring testing around the software development lifecycle itself rather than a fixed calendar date.
Each major release phase, from initial self-service functionality through more complex benefit calculation, enrollment, and payment features, was tested as its own scoped effort before moving forward, so new capabilities were vetted before reaching production.
Testing followed the code through the pipeline: starting on the development system, continuing through regression testing as fixes were applied, and concluding with validation in production.
Every workflow and user role was tested with automated tooling and manual exploitation, benchmarked against the OWASP Top 10, and run both with and without valid credentials to catch authorization gaps a scanner alone would miss.
Every identified vulnerability was retested as its own dedicated task after remediation, so fixes were verified to actually hold before a phase was considered complete.
Security validation remained connected to each stage of delivery instead of being isolated at the end of the modernization program.
Initial application security testing begins on the development system.
Each major release phase receives a dedicated testing scope.
Identified vulnerabilities are addressed by the development team.
Fixes are retested to verify that vulnerabilities have actually been resolved.
Final validation confirms security in the live production environment.
Across multiple release phases spanning several years, Cyber Castellum identified and validated the remediation of vulnerabilities in each new set of application features before they reached end users, protecting a system that directly touches the financial security of the people who depend on it.
The agency has continued the partnership across every phase of the program, including the final phase retiring the legacy mainframe system entirely.
By structuring security testing around the SDLC itself rather than treating it as a final gate, the agency was able to modernize a mission-critical legacy system on schedule, with confidence that each new capability was tested under real-world conditions and verified after remediation before it reached the people relying on it.
Cyber Castellum specializes in SDLC-integrated application security testing and penetration testing for government agencies undergoing large-scale system modernization across New York State.
Book a consultation to build security into your SDLC and address vulnerabilities before they reach production.
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