Senior Security Engineer (Offensive)

cyber; Northern (KY); Hybrid; USD 140,000 - 210,000; Full time

Benefits offered by this job

Remote-first policy

Reimbursement program

Medical/dental/vision

401k match

Wellness stipend

Home office setup

Job summary

Offchain is seeking a Senior Security Engineer to emulate real-world adversaries, perform hands-on tests, and lead red team efforts to strengthen our infrastructure and ecosystem tools.

You will collaborate with detection, threat intelligence, and incident response groups, build offensive tools, mentor junior staff, and help ensure SOC 2 compliance while tracking evolving threats.

Qualifications

• 5+ years in offensive security, pentesting, red teaming or related field.
• Experience with code audits to remediate security issues.
• Experience with binary exploitation.
• Mastery of AWS & attack techniques and configuration weaknesses.
• Strong understanding of MITRE ATT&CK.
• Web application security knowledge incl OWASP Top 10, ASVS.
• Proficient with offensive security tools like Burp Suite and Nuclei.
• Strong programming in Python or Go, with tool/automation experience.
• Excellent written and verbal communication; clear risk-focused recommendations.
• A attacker mindset with risk assessment across complex systems.

Responsibilities

• Emulate adversaries to surface vulnerabilities across infrastructure.
• Run hands-on penetration tests; lead red team exercises.
• Collaborate with blue/defense teams to test and strengthen detection.
• Build, maintain offensive tools, scripts, and automation.
• Support incident investigations with log analysis and root-cause reviews.
• Stay current on threats; share research internally and with community.
• Own projects end-to-end; mentor juniors and promote learning.

Skills

Offensive security

Penetration testing

Code audits

AWS security

MITRE ATT&CK

Web app security

Python/Go

Communication

Adversary emulation

Tools

Burp Suite

Nuclei

Job description

At Offchain, we aren’t just building products: we’re leading a movement. As pioneers in blockchain scalability and security, we're at the forefront of transforming how the world interacts with decentralized applications. We're laying the foundation that will define the next generation of digital commerce, governance, and human interaction. This involves tackling real-world challenges that come with scaling blockchain technology, without compromising on its core principles: decentralization, security and transparency. At the center of this vision is our people. Our team is made up of thinkers and doers that embrace new challenges and seek solutions that push existing boundaries. If you’re energized by solving unprecedented problems, and believe in the role that decentralized systems will play in creating a more equitable digital future, then we want to hear from you.

Why Offchain?

Offchain is setting the pace for the entire Ethereum ecosystem. We built the Arbitrum stack that powers Arbitrum One, the most widely adopted Ethereum scaling solution that exists today. Arbitrum’s ecosystem is undergoing tremendous growth with hundreds of projects and dApps on Arbitrum One today. Over 100 different teams have used Offchain technology to build their own Arbitrum chains. Major players in the space, Robinhood, BlackRock, Ethena Labs, Securitize, Aave, and Apechain are all using the Arbitrum stack. Arbitrum’s thriving ecosystem wouldn’t exist without our advanced technology stack. Arbitrum, Prysm, ZeroDev. These aren’t just product names. These are tools that are actively reshaping what's possible on Ethereum and advancing its core infrastructure. To top it all off? We’re backed by $124 million in funding. We’ve demonstrated consistent execution with billions in secured value, thousands of supported projects, and infrastructure processing millions of transactions seamlessly.

The Role

• As a Senior Security Engineer at Offchain, you will emulate the real-world tactics, techniques, and procedures of sophisticated adversaries to surface vulnerabilities across our infrastructure and ecosystem tools
• You’ll run hands‑on penetration tests, lead red team exercises, and work side‑by‑side with blue team partners to test, refine, and strengthen detection and response capabilities
• Your efforts will directly shape how Offchain designs, launches, protects, and achieves compliance for the infrastructure that powers millions of users and applications - including key standards such as SOC 2

What you’ll do:

• Conduct comprehensive code audits across a variety of internal applications and infrastructure
• Conduct comprehensive penetration tests across cloud environments (AWS), infrastructure, and backend applications
• Collaborate with detection engineering, threat intelligence, and incident response groups to review security controls, uncover coverage gaps, and enhance overall detection quality
• Build, maintain, and evolve custom offensive tools, scripts, and automation frameworks to increase assessment speed
• Offer offensive security expertise during incident investigations, including log analysis and root cause reviews
• Keep up with evolving threats, vulnerabilities, and attack methods; share research internally and engage with the wider security community
• Own offensive security projects from start to finish, mentor junior team members, and cultivate a culture of ongoing learning and knowledge exchange

What you’ll need:

• 5+ years of experience in offensive security, penetration testing, red teaming, or a closely related field
• Extensive experience with conducting code audits to identify and remediate security issues
• Experience with binary exploitation
• Mastery of AWS & specific attack techniques and configuration weaknesses
• Strong understanding of adversary tactics and frameworks like MITRE ATT&CK
• In-depth knowledge of web application security, including OWASP Top 10, ASVS, and common vulnerability categories
• Proficiency using offensive security tools such as Burp Suite, nuclei and similar frameworks
• Strong programming skills in Python, Go, or similar languages, with proven experience developing tools or automation
• Excellent written and verbal communication skills, with the ability to present complex technical details as clear, risk‑focused recommendations
• A natural ability to think like an attacker - creative, determined, and skilled at assessing risk across complex systems

Nice-to-haves

• Web3 / blockchain security exposure: smart contract auditing, bug bounty hunting (e.g., Immunefi, Code4rena), or DeFi protocol review
• Familiarity with Ethereum L1 / L2 node architecture and security risks
• Experience in blockchain infrastructure penetration testing

Perks:

• Remote‑first global workforce + NY office
• Professional reimbursement program (facilitates industry conference attendance, certifications, and more)
• Medical, dental & vision coverage (US + some other countries)
• 401k retirement plan + company match (US only)
• Wellness stipend
• Home office set up / ergonomic equipment program

Attention Offchain Job Seekers:

This role cannot be performed in California, or Colorado.

Please be advised that there has been a rise in fraudulent recruiter activities, particularly within the Web3 space. If you would like to confirm whether someone is an Offchain employee or the legitimacy of an offer you received, please email [e-mail]

At Offchain, we are committed to building a welcoming and supportive workplace for all employees, regardless of their background or identity. We strive to create an environment where everyone feels valued and has an equal opportunity to succeed and thrive. We encourage candidates from all walks of life to apply and join our team.

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses and identifying potential inconsistencies or verification signals in application materials based on available information. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.