Application Security Engineer

About KX
KX software powers the time-aware data-driven decisions that enable fast-moving companies to outpace competitors, realizing the full potential of their AI investments. The KX platform delivers transformational value by addressing data challenges related to completeness, timeliness and efficiency, ensuring companies understand change over time and can achieve faster, more accurate insights at any scale, cost-effectively.

KX is essential to the operations of the world's top investment banks, aerospace and defence, high-tech manufacturing, healthcare and life sciences, automotive and fleet telematics organizations. The company has established offices and a robust customer base across North America, Europe, and Asia Pacific.

Role Overview
KX Systems is looking for an Application Security Engineer to work directly with development teams and embed security into the way code gets written, tested, and shipped. This role owns the technical side of product security: finding vulnerabilities before they reach production, building the tooling that catches them automatically, and giving developers the guidance they need to fix issues without slowing delivery down. 
You'll be the technical bridge between the security function and engineering, working inside the SDLC rather than auditing it from outside. 

Location & Workplace Type
Hybrid working model based out of our Belfast or Newry office.

Responsibilities

Key Responsibilities

• Partner with development teams throughout the SDLC to identify, prioritise, and remediate application security vulnerabilities. 
• Design, implement, and tune SAST, DAST, and SCA tooling integrated into CI/CD pipelines (e.g. SonarQube, Snyk, or equivalent). 
• Perform manual code review and security testing on high-risk components where automated tooling isn't sufficient. 
• Conduct threat modelling for new features and architectural changes, and work with engineers to design out risk early rather than patch it later. 
• Own the triage, prioritisation, and remediation tracking of application vulnerability findings, including from penetration tests and bug bounty reports. 
• Build and maintain secure coding standards and guidelines, and provide hands-on guidance to developers rather than just flagging findings. 
• Run or support a security champions programme within engineering to scale secure coding practice beyond the security team. 
• Review third-party libraries and dependencies for known vulnerabilities and licence risk as part of the software supply chain. 
• Support secure API design and review, including authentication, authorisation, and data handling patterns. 
• Contribute application security evidence and control narratives to ISO 27001, SOC 2, and customer security assessments. 
• Work with the Product Security function on secure-by-design reviews for new products and features. 
• Provide technical guidance during security incidents involving application-layer vulnerabilities. 

Requirements

Skills

• Hands-on experience in application security, with real code review and vulnerability remediation work, not just tool operation.
• Working knowledge of common vulnerability classes (OWASP Top 10, injection, auth flaws, SSRF, deserialisation, etc.) and how to explain and fix them to developers.

• Experience with SAST/DAST/SCA tooling in a CI/CD context, and the judgement to tune it so findings stay actionable rather than noise.
• Ability to read and reason about code in Java, Python, C++, or C#, with working proficiency in at least one and enough familiarity with the others to review and discuss findings.
• Threat modelling experience, or a clear grasp of the method even without a formal certification.
• Comfortable working as an embedded technical partner to developers, not as a gatekeeper.
• Familiarity with secure API design and cloud-native application patterns.
• Experience supporting compliance frameworks (ISO 27001, SOC 2) is a plus, not a prerequisite.

Core Technologies 
Java, Python, C++, C#, SAST/DAST/SCA tooling (e.g. SonarQube, Snyk), CI/CD pipelines, secure coding standards, threat modelling, OWASP Top 10, API security, software supply chain security, vulnerability management.

Benefits

Why Choose KX
Data Driven: We lead with instinct and follow fact.
Naturally Curious: We lean in, listen and learn fast.
All In: We take ownership, take on challenges and give it our all.

Benefits

• Competitive Salary
• Individually tailored training and skills development
• Private healthcare package and Employee Assistance Programme
• Enhanced maternity and paternity package
• Wellness Days and Volunteer Days