Senior Blockchain Security Engineer

Join Our Team as a Senior Blockchain Security Engineer at Modus Create!

We're looking for a Senior Blockchain Security Engineer with a DevSecOps mindset to secure the next generation of decentralized applications. You will bring deep expertise in smart contract auditing, cryptographic principles, and penetration testing for advanced blockchain ecosystems. In this role, you'll work with cross-functional teams to provide strategic consulting, secure our customers' end-to-end product development lifecycle, and build solutions that protect against sophisticated and evolving threats.

About You:

You are a security professional passionate about the unique challenges of decentralized systems. You excel at moving beyond traditional security checklists to perform deep architectural analysis and threat modeling. You understand that in the blockchain space, security is not just a feature but the foundation of trust. You will be responsible for safeguarding our clients' assets and reputation by ensuring the integrity and resilience of their on-chain protocols and infrastructure.

You possess deep knowledge of both cryptography and the principles underlying distributed systems. You have a strong grasp of the cryptographic primitives that underpin Proof-of-Stake systems, particularly Cardano's Ouroboros protocol, including the role of Verifiable Random Functions (VRFs) in leader selection. You're familiar with modern privacy-preserving techniques such as ZK-SNARKs and their application in blockchain environments. Your expertise allows you to evaluate the security of on-chain protocols and cryptographic implementations beyond standard data-in-transit encryption.

You hold a Master’s degree in Cryptography, Cybersecurity, or a related technical field, equipping you with a strong theoretical and applied foundation for secure systems design. You bring hands-on experience with blockchain penetration testing.

You're comfortable writing your own code to streamline security processes and enhance testing frameworks. Plus, you have a network engineer’s understanding of LANs, WANs, TCP/IP, and VLANs, backed by hands-on experience monitoring network traffic and responding to incidents.

Key Responsibilities:

• Conduct comprehensive security assessments of blockchain applications, including in-depth smart contract audits (in languages like Plutus and Aiken) and node security analysis.  
• Identify, model, and develop mitigation strategies for complex, blockchain-specific vulnerabilities, particularly those unique to the EUTXO model (e.g., Double Satisfaction, UTXO contention, state forgery).  
• Perform architectural reviews and threat modeling of dApp designs, focusing on concurrency patterns and potential economic denial-of-service vectors.  
• Develop and execute a holistic security strategy that combines cryptographic evaluations, penetration testing, and automated security checks seamlessly integrated into development workflows.  
• Translate complex customer needs into actionable security requirements, providing expert guidance and training to development teams on secure coding practices.

What You'll Bring:

• Significant professional experience in software development, DevSecOps, or a dedicated security engineering role.
• Demonstrated expertise in penetration testing methodologies, including reconnaissance, scanning, and exploitation, using tools like Burp Suite and Nmap.
• A strong command of functional programming principles and proficiency in languages like Haskell, with direct experience in Cardano smart contract languages such as Plutus or Aiken being a major asset.   
• A deep, practical understanding of cryptographic principles, including symmetric and asymmetric encryption and their application in securing communications and data in distributed systems.   
• An advanced degree (Master's or PhD) in Cybersecurity, Computer Science, or a related technical field, or equivalent deep practical experience in the field.
• Hands-on experience securing cloud environments in GCP, AWS, or Azure.
• Proficiency in Python or shell scripting to automate security processes and enhance testing frameworks.
• A network engineer’s understanding of LANs, WANs, TCP/IP, and VLANs, with experience in traffic analysis and incident response.

Bonus Points For:

• Experience with formal verification and mathematical proof tools like Lean4, Agda, or Coq to provide the highest level of assurance for smart contracts.   
• Knowledge of game theory and economic modeling as applied to consensus protocol security (e.g., analyzing Ouroboros for grinding attack vectors).   
• Industry-recognized certifications such as CISSP, CEH, or OSCP.
• Experience administering GitHub organizations, managing permissions, and implementing security policies at scale.

You’ll Love:

• Mentoring and coaching both clients and Modus teammates from the comfort of home.
• Deep-diving into customer needs and translating them into actionable requirements.
• Exploring new tech and continuously learning—because software is always evolving!
• Sharing your knowledge and participating actively in the community.

Team Collaboration:

• Some overlap with EST hours daily is expected.
• Reliable high-speed internet is a must!

Team Culture:

At Modus, a fast-growing, remote-first company, you’ll experience various exciting projects! Here’s a taste of what you might do:

• Giving back: Participate actively through opportunities such as blog posts, open source contributions, and event speaking.
• Travel & connections: Meet fantastic people during our remote meet-ups! It’s all about collaboration and fun! Global environment and diversity at its best.
• Teaching and learning: Work in active teams on internal and external projects, staying up-to-date with the latest technologies.
• Being a self-starter:  Autonomy and proactivity are the keys to succeed at Modus.
• Client interaction: Represent Modus and our values while connecting directly with our clients, some of the world’s biggest brands.
• Growth: Enjoy comprehensive learning benefits with access to over 12,000 courses. Your growth is our priority!

About us: 

Founded in 2011, Modus is a global, fully remote team of world-class technologists who thrive in a collaborative, innovative environment. We were fully remote before it was cool! We support organizations on their digital transformation journey through strategic consulting and full lifecycle product development, partnering with industry leaders including Atlassian, GitHub and AWS. Recognized as one of the Inc. 5000 Fastest Growing Private Companies for nine years and a top remote work company by FlexJobs, we have helped some of the world’s largest brands deliver powerful digital experiences.

We combine boutique expertise with enterprise-scale capabilities. As a GitHub partner with a world-class team, we help organizations innovate and solve complex challenges for Fortune 500 companies and beyond, we want to hear from you.

Perks of working with us:

• Remote work with flexible working hours.
• Modus Global Office Program: for when you want to get out of your home, we offer on-demand access to private offices, meeting rooms, co-working spaces and business lounges in locations in over 120 countries. 
• Employee Referral Program.
• Client Referral Program. 
• Travel according to client or team needs.
• The chance to work side-by-side with thought leaders in emerging tech.
• Access to more than 12,000 courses with a licensed Coursera account.
• Possibility to obtain paid certification/courses if they align with company goals and are relevant to the employee's role.

Additional benefits might apply, contingent on your location.

By joining our team, you’ll be part of a winning squad that plays to each other’s strengths and celebrates every success together. Apply now and show us you’ve got what it takes to take your consulting skills to the next level with Modus Create!