Senior Security Engineer, Application Security

Blockchain.com is the world's leading software platform for digital assets, powering the largest production blockchain platform globally. We are driven by a passion to code, create, and ultimately build an open, accessible, and fair financial future—one line of code at a time.

As we scale our platform to serve millions of people each day, we seek a Senior Application Security Engineer to join our dedicated security team.

At Blockchain.com, security is more than a set of policies—it's a core mindset. As we continue to innovate in the crypto space, you will tackle some of the most complex problems around securing a distributed financial platform. The Security team is responsible for guiding the design and implementation of secure systems across the company. Using a comprehensive range of tools and methodologies, we identify and mitigate security risks proactively, ensuring the protection of our users, stakeholders, and systems.

WHAT YOU WILL DO

• Collaborate with Engineering teams to define security requirements and conduct design assessments early in the development lifecycle.
• Perform in-depth code reviews throughout the product lifecycle and conduct penetration tests on both internal and externally-facing services.
• Develop, communicate, and enforce best practices for secure development and deployment of services.
• Continuously improve the Secure Software Development Lifecycle (SDLC) process, driving the adoption of the “Security by Design” principle.
• Create and integrate software and tooling to enforce secure baselines in software development, deployment, and release.
• Conduct security reviews of development processes and documentation, ensuring consistency with security standards.
• Design and implement security libraries and tooling for critical operations (e.g., data encryption, authentication, logging, access control, and input validation).
• Assist Engineering teams in implementing security fixes and develop proactive strategies to mitigate vulnerabilities in their code.

WHAT YOU WILL NEED

• Proven experience with secure software development practices, preferably in JVM-based languages such as Java and Kotlin.
• Demonstrated expertise in performing code reviews, developing secure coding standards, and building secure software across multiple types of projects.
• Significant experience working in highly regulated environments, with previous involvement in cryptocurrency-related projects being a strong plus.
• Strong knowledge of OWASP standards, Static Application Security Testing (SAST), Dynamic Application Security Testing (DAST), and Software Composition Analysis (SCA) tools. Familiarity with integrating these tools into CI/CD pipelines is highly desirable.
• Experience with security monitoring techniques and tools for detecting and mitigating threats, ensuring traceability across the stack.
• A strong appetite for learning and a dedication to applying best practices in every project.
• The ability to apply pragmatic solutions to complex security challenges.
• A commitment to integrity, transparency, and excellence in all aspects of work.

CERTIFICATIONS (preferred but not required):

• Certified Information Systems Security Professional (CISSP)
• Certified Secure Software Lifecycle Professional (CSSLP)
• Certified Ethical Hacker (CEH)
• Offensive Security Certified Professional (OSCP)
• AWS Certified Security – Specialty or similar cloud security certifications

COMPENSATION & PERKS

• Amazing and accessible office location in the heart of London.
• Unlimited vacation policy.
• Apple equipment.
• Full-time salary based on experience and meaningful equity in an industry-leading company.
• London Benefits: Private Medical Insurance (BUPA), Dental, Pension, Life, Short Term & Long Term Disability
• The opportunity to be a key player and build your career at a rapidly expanding, global technology company in an emerging field
• Flexible work culture 

APPLICATION:

• Submit your LinkedIn profile.
• Provide links to your GitHub, Stack Overflow, personal website, or blog (if applicable)

Blockchain is committed to diversity and inclusion in the workplace and is proud to be an equal opportunity employer. We prohibit discrimination and harassment of any kind based on race, religion, color, national origin, gender, gender expression, sex, sexual orientation, age, marital status, veteran status, disability status or any other characteristic protected by law. This policy applies to all employment practices within our organization, including hiring, recruiting, promotion, termination, layoff, recall, leave of absence, and apprenticeship. Blockchain makes hiring decisions based solely on qualifications, merit, and business needs at the time.

You may contact our Data Protection Officer by email at dpo@blockchain.com. Your personal data will be processed for the purposes of managing Controller’s recruitment related activities, which include setting up and conducting interviews and tests for applicants, evaluating and assessing the results thereto, and as is otherwise needed in the recruitment and hiring processes. Such processing is legally permissible under Art. 6(1)(f) of Regulation (EU) 2016/679 (General Data Protection Regulation) as necessary for the purposes of the legitimate interests pursued by the Controller, which are the solicitation, evaluation, and selection of applicants for employment.

Your personal data will be shared with Greenhouse Software, Inc., a cloud services provider located in the United States of America and engaged by Controller to help manage its recruitment and hiring process on Controller’s behalf.  Accordingly, if you are located outside of the United States, your personal data will be transferred to the United States once you submit it through this site. Because the European Union Commission has determined that United States data privacy laws do not ensure an adequate level of protection for personal data collected from EU data subjects, the transfer will be subject to appropriate additional safeguards under the standard contractual clauses. 

Your personal data will be retained by Controller as long as Controller determines it is necessary to evaluate your application for employment.  Under the GDPR, you have the right to request access to your personal data, to request that your personal data be rectified or erased, and to request that processing of your personal data be restricted. You also have the right to data portability. In addition, you may lodge a complaint with an EU supervisory authority.