Senior App Security Engineer — FinTech & AI Security Lead

OANDA; Kraków; On-site; PLN 210,000 - 330,000; Full time

Job summary

OANDA, a leading global FinTech, seeks a Senior Application Security Engineer to strengthen our secure software delivery across a multi-language stack and cloud environment. You will influence design, mentor teams, and build security-first capabilities from DevSecOps pipelines to AI security tooling.

You will collaborate with cross-functional engineering teams, perform threat modeling, and drive secure coding practices while focusing on scalable defense-in-depth across the product ecosystem.

Qualifications

• 2-5 years of relevant technical experience, with 1-2+ years focused specifically on application security / security engineering.
• Expert-level knowledge of web application vulnerabilities (OWASP Top 10), attack vectors and secure code review.
• Strong ability to develop in and navigate security pitfalls in at least one primary programming language (e.g., Python, Go, Java, C#, or JavaScript/C++).
• Hands-on experience with modern testing tools (SAST, DAST, IAST, SCA, penetration testing frameworks).
• Working knowledge of cloud platforms (AWS, Azure, or GCP), networking, databases, and containerized/IaC environments.
• Ability to simplify complex security challenges and drive proactive solutions with urgency, high energy, and teamwork.

Responsibilities

• Lead & Advocate: Provide technical leadership in application security, conduct threat modeling, lead design reviews, and establish secure coding practices.
• Build & Remediate: Directly build security-critical components and fix vulnerabilities across multiple languages (JS, Go, Python, C++, Java).
• Apply Defense-in-Depth: Touch every layer of our stack — from system hardening and Terraform (IaC) cloud security to reviewing C++ code and applying modern cryptography/secrets management (PKI, hashing).
• Automate DevSecOps: Implement static code analysis, fuzzing, composition analysis, to make security proactive and effortless for developers.
• Threat Modelling: Develop and lead on Threat Modelling exercises to identify risk, threats and vulnerabilities in the development phase of our applications
• Pioneer AI Security: Identify and implement best practices for secure AI development and AI security tooling.
• Secure Supply Chains: Work with dev teams to identify, track, and remediate third-party library vulnerabilities and supply-chain risks.

Skills

OWASP Top 10 knowledge

Web app vulnerabilities

Programming in Python/Go/Java/C#/JS/C

SAST/DAST/IAST/ SCA

Cloud/AWS/Azure/GCP

DevSecOps automation

Tools

Terraform

Cloud security tooling

Job description

OANDA, a leading global FinTech, seeks a Senior Application Security Engineer to strengthen our secure software delivery across a multi-language stack and cloud environment. You will influence design, mentor teams, and build security-first capabilities from DevSecOps pipelines to AI security tooling.

You will collaborate with cross-functional engineering teams, perform threat modeling, and drive secure coding practices while focusing on scalable defense-in-depth across the product ecosystem.