Nazar Yakymiv
Nazar Yakymiv is a security consultant at K2 Integrity/Leviathan Security Group. His work focuses on conducting black-, gray-, and white‑box application penetration testing, as well as contributing to security research and development initiatives. Nazar specializes in security testing of web applications, APIs, external networks, and cloud‑based systems in commercial settings. Prior to joining K2 Integrity/Leviathan […]
Shane Tachick
Shane Tachick is an experienced information security consultant specializing in penetration testing, security assessments, and risk communication. With a strong technical background and a strategic approach to security, he helps organizations identify vulnerabilities, mitigate risk, and strengthen overall security posture. Shane has led offensive security engagements aligned with compliance frameworks such as PCI, FedRAMP, and […]
Viktor Sytnik
Viktor Sytnik is a technical director at K2 Integrity/Leviathan Security Group, where he leads advanced cybersecurity engagements and oversees black-, grey-, and white-box penetration testing projects. He specializes in application and mobile penetration testing and cloud security, providing expert security architecture guidance while mentoring consultants in the identification and remediation of complex vulnerabilities. Prior to […]
Viacheslav Sych
Viacheslav Sych is a software engineer with more than a decade of experience in software development, specializing in back-end web and desktop applications. His work spans the full software development lifecycle, with a strong focus on building, maintaining, and refining complex systems across a range of platforms and technologies. Viacheslav has contributed to the development […]
Ankur Sundara
Ankur Sundara is a security consultant with K2 Integrity/Leviathan Security Group, where he provides security architecture guidance and conducts black- and white-box application penetration testing and secure code reviews for clients. His work focuses on web, browser, and cloud security, with additional experience testing mobile and native applications. He is recognized for a practical, engineering-driven […]
Anton Shantir
As managing director at K2 Integrity/Leviathan Security Group, Anton Shantir leads strategic, AI-driven cybersecurity initiatives and oversees organizational transformation programs for clients navigating rapidly changing digital landscapes. With experience in artificial intelligence, machine learning, and resilient systems, he assists clients in securing complex environments and enabling sustainable business continuity. Anton’s leadership background includes senior technology […]
Yurii Sanin
Yurii Sanin is a senior security consultant with K2 Integrity/Leviathan Security Group. A member of the firm’s Technical Services team, Yurii specializes in white- and black-box penetration testing and delivers security assessments across web, API, cloud, and mobile applications. His work includes in-depth source code reviews, architecture analysis, and security research and development (R&D), with […]
Mark Rosnick
Mark Rosnick is a security consultant at K2 Integrity/Leviathan Security Group. With more than 25 years of experience defending computer systems, Mark focuses on offensive security, performing penetration tests across cloud infrastructure platforms, global data networks, web frameworks and applications, gaming systems, operating systems, and embedded hardware and firmware. He identifies and exploits low-level vulnerabilities […]
Serhii Romanko
Serhii Romanko is a senior security consultant at K2 Integrity/Leviathan Security Group, where he provides security architecture guidance and conducts comprehensive security assessments across applications and cloud environments. With almost a decade of cybersecurity experience, he conducts black- and white-box penetration testing, source code review, and security configuration reviews of cloud platforms, including AWS and […]
Viktoriia Reitsenshtein
Viktoriia Reitsenshtein is a senior security consultant at K2 Integrity/Leviathan Security Group. She provides security architecture guidance and performs black-, gray-, and white-box penetration testing of applications. Her work also includes security research and development, as well as training and mentoring junior security consultants. Her technical expertise spans web and mobile application penetration testing, cloud […]