Application Security Engineer

Responsibilities

The Application Security Engineer will triage and validate security findings while partnering with engineering teams to remediate vulnerabilities. They will also integrate security tooling into CI/CD pipelines and perform threat modelling to ensure the platform remains secure.

Requirements

Candidates must have a degree in a relevant field and at least 5 years of experience in application security, software development, or DevSecOps. Proficiency in secure coding practices, application security tools, and the ability to communicate technical risks to various audiences are required.

Skills

• Application Security
• SAST
• SCA
• DAST
• C#
• .NET
• Threat Modelling
• CI/CD
• DevSecOps
• Python
• PowerShell
• OWASP Top 10
• Security Architecture
• Vulnerability Management
• Automation
• AI-assisted tooling

Benefits

• Medical Plan
• Dental Insurance
• Vision Insurance
• Life Insurance
• Short Term Disability
• Long Term Disability
• Vacation Time
• Paid Holidays
• Professional Development
• Retirement Plan

About this role

At OneStream, we're on a mission to empower every Finance organization and professional to exceed their potential. Our global teams span continents, cultures, and time zones, united by a shared purpose as we build the operating system for modern Finance and help organizations move with greater speed, clarity, and confidence.
That mission comes to life through our people. Behind every innovation, customer success, and milestone are talented people working together to make a difference. That's why we're looking for people who are bold enough to think big, authentic in how they lead and collaborate, curious about what's possible, and committed to delivering results.
Want a closer look before you apply? Explore our Careers site to learn more about our people, culture, and benefits.
Summary
We are looking for an Application Security Engineer to join the Information Security team. In this role, you will help keep the OneStream platform secure by triaging and validating findings from application security tools, partnering with engineering teams on practical remediation, and supporting security design reviews and threat modelling for new features throughout the SDLC. You will also use automation and AI-assisted tooling to take on repetitive work, such as reviewing and summarizing findings, so the team can focus on higher-impact security problems.
The ideal candidate has experience in software engineering and security, with a solid foundation in secure development practices, familiarity with application security tools (SAST, SCA, and DAST), and a passion for securing our platform for our customers. Working knowledge of C# and .NET is a bonus. We are looking for a go-getter who is eager to learn, collaborates well with teams across all levels of the organization, and brings a pragmatic approach to security that keeps delivery moving. This position requires the ability to explain and discuss technical details with both technical and non-technical audiences.
Primary Duties and Responsibilities
Triage and validate findings from application security tools (SAST, SCA, and DAST), prioritizing by exploitability and real-world risk.
Partner with Development and Engineering teams to remediate vulnerabilities with clear, practical guidance.
Participate in security architecture reviews and threat modelling for new features and services.
Integrate and tune application security tooling in CI/CD pipelines so security checks fit naturally into developer workflows.
Use AI-assisted tools and automation to streamline repetitive tasks such as reviewing and summarizing findings, removing duplicates and false positives, creating tickets, and reporting.
Write scripts and lightweight tooling to automate recurring security workflows.
Review the SDLC and software supply chain, including third-party dependencies, to identify opportunities to improve security.
Perform targeted manual validation of findings when needed to confirm impact.
Track remediation progress, and document and report security concerns and trends.
Contribute to secure development guidance, standards, and developer education.
Work with other members of the Security team to share findings and improve overall security posture.
Required Education and Experience
BSc/BA in Computer Science, Engineering, or relevant field, with 5+ years of experience in application security, software development, or DevSecOps
OR
MSc/MA in Computer Science, Engineering, or relevant field, with 1+ year of experience in application security, software development, or DevSecOps
OR
Assoc. in Computer Science, Engineering, or relevant field, with 5+ years of experience in application security, software development, or DevSecOps
Preferred Education and Experience
Experience writing or reviewing C# & .NET code (a strong plus).
Software development background, with an understanding of secure coding practices and common vulnerability classes (e.g., OWASP Top 10).
Hands-on experience with SAST, SCA, and/or DAST tools and triaging their output.
Experience using AI tools or LLMs to automate repetitive work, such as reviewing findings, summarizing results, or drafting remediation guidance.
Experience with CI/CD pipelines and DevSecOps practices.
Scripting or automation experience (e.g., Python, PowerShell).
Familiarity with threat modelling methodologies (e.g., STRIDE).
Exposure to Burp Suite or similar tools for validating web application findings.
Familiarity with security risk management, SOC2, FedRAMP, security policies & procedures, or security auditing.
Any industry recognized certifications, for example:
CompTIA Security+
Certified Secure Software Lifecycle Professional (CSSLP)
GIAC Secure Software Programmer - .NET (GSSP-.NET)
Other application security or secure development certifications
Outstanding communication skills
Knowledge, Skills, and Abilities
Ability to triage and prioritize security findings based on exploitability and business impact.
Working knowledge of application security tools such as SAST, SCA, and DAST.
Understanding of secure design principles, with the ability to contribute to security architecture reviews and threat modelling.
Enthusiasm for using AI and automation to reduce repetitive manual work.
Collaborative and pragmatic, with the judgement to fit security into how teams already work.
Go-getter: self-motivated, self-starter, and eager to learn.
Organized, with strong reasoning skills and good judgement.
Ability to multitask and prioritize a variety of projects.
Comfortable communicating with all levels of management.
Experience with OneStream Software not required, but experience with any financial consolidation package is a plus.
Benefits at OneStream
OneStream employees are passionate, hardworking individuals who go above and beyond to keep our customers happy and follow through on our mission statement. They consistently deliver the best and in turn, we make every effort to keep them cared for and happy. A sam...

About OneStream

Software Development · 1,001-5,000 employees · headquartered in Birmingham, MI