Blockchain Security Engineer

As a Blockchain Security Engineer at ING, you will design and implement secure custody and wallet management capabilities for the Digital Asset Services (DAS) platform. You join an international technology organization building critical systems that support ING's digital transformation, focusing on blockchain SaaS integration, wallet management, custody workflows, and secure key lifecycle management.

What you'll do

• Design, develop and maintain Java-based backend services supporting digital asset operations
• Build APIs and microservices for wallet administration, asset transfers, transaction signing and custody workflows
• Develop integration components with blockchain SaaS vendors and custody providers
• Design secure key management processes across the entire key lifecycle
• Implement integrations with HSMs (Hardware Security Modules), vault solutions and key custody platforms
• Support cryptographic operations including transaction signing, encryption and secure key storage
• Apply security-by-design principles throughout application development
• Conduct security reviews and threat modeling for new capabilities
• Design and implement wallet provisioning and lifecycle management capabilities
• Build and optimize custody workflows for institutional digital asset operations
• Support multi-signature and approval workflows
• Implement controls for segregation of duties and privileged access management
• Ensure high availability, scalability and resilience of critical digital asset services
• Work closely with DevOps and Security Engineers to automate secure deployments
• Contribute to CI/CD pipelines and infrastructure-as-code initiatives
• Support operational readiness, monitoring and security incident analysis
• Collaborate with architects, blockchain engineers, compliance specialists and product stakeholders
• Participate in architecture reviews and security assessments
• Provide technical guidance on secure digital asset platform design

What you bring

• Bachelor's degree in Computer Engineering, Software Engineering, or a related discipline
• 5+ years of professional software engineering experience
• Strong hands-on experience with Java (Java 17+ preferred)
• Experience with Spring Boot and microservice architectures
• Strong knowledge of RESTful APIs and event-driven architectures
• Good understanding of container technologies (Docker, Kubernetes)
• Fluent English communication skills (C1 level or above)

Nice to have

• Experience with MPC (Multi-Party Computation) custody solutions
• Experience integrating institutional custody providers
• Knowledge of blockchain security and smart contract risks
• Experience with cloud platforms (Azure preferred)
• Familiarity with ISO 27001, SOC2 and financial security standards
• Experience working in Agile/Scrum environments

What we offer

• 14 days of welcome leave, even in your first year
• Flexible hybrid working model: two days per week at the Vadistanbul office during three weeks of the month, with one week fully remote each month
• Additional remote working opportunities throughout August
• Training budget and Udemy partnership
• Comprehensive health insurance for you and your family
• Private Pension Plan
• Meal Card
• Transportation Allowance
• MultiSport Membership
• English Language Development Support
• Global mobility and international career opportunities
• Challenging projects and continuous learning opportunities

About ING

ING is a global financial institution with 65,000 employees and operations in approximately 40 countries. We are transforming banking through digital innovation while maintaining integrity and prioritizing customer interests.