At eBay, we're more than a global ecommerce leader — we’re changing the way the world shops and sells. Our platform empowers millions of buyers and sellers in more than 190 markets around the world. We’re committed to pushing boundaries and leaving our mark as we reinvent the future of ecommerce for enthusiasts. Our customers are our compass, authenticity thrives, bold ideas are welcome, and everyone can bring their unique selves to work — every day. We're in this together, sustaining the future of our customers, our company, and our planet. Join a team of passionate thinkers, innovators, and dreamers — and help us connect people and build communities to create economic opportunity for all. About the team and the role:eBay’s Cloud Security Engineering team builds the foundational security services that protect our global marketplace. The team develops and operates secure, scalable cryptographic platforms that enable trusted transactions, secure communications, and strong identity guarantees across millions of users and services. As a Senior Software Engineer – Cryptography & Platform Security, you will build and implement high-assurance cryptographic services that underpin authentication, digital signatures, key management, and secure data protection across eBay’s distributed systems. You will collaborate closely with platform and infrastructure teams to embed robust cryptographic protections into our services and help shape eBay’s long-term security posture. What you will accomplish:Design and deliver cryptographic services and libraries that enable secure encryption, digital signatures, and key management for high-scale, global platforms. Build and evolve systems using public key cryptography (such as RSA, ECC, and DSA) to support secure transactions, identity, and communications across distributed services. Develop and improve PKI infrastructure, including certificate lifecycle management and trust frameworks, to strengthen authentication and service-to-service trust. Integrate cryptographic capabilities into Java-based services using JCA/ JCE and hardware-backed security modules (for example PKCS#11, KMIP, TPM 2.0) to protect sensitive data and keys. Lead and participate in threat modeling, security reviews, and cryptographic design validation to proactively identify and mitigate risks. Improve the performance, scalability, and resilience of cryptographic operations in high-throughput environments while knowing the latest modern standards, vulnerabilities, and approaches. What you will bring:Bachelor’s degree, Master’s degree, or equivalent experience in Computer Science, Engineering, or a related field is required. Typically, 7 years of software engineering experience with a focus on security and cryptography is needed. Proven hands-on experience with cryptographic algorithms and protocols, including RSA, ECC, DSA, and digital signatures, applied in production systems. Strong understanding of public key infrastructure (PKI), certificate management, and trust models in large-scale, distributed environments. Proficiency in Java, including experience using JCA/ JCE or building secure J 2 EE-based applications that integrate cryptographic services. Experience implementing or integrating with key management standards and interfaces such as PKCS#11, KMIP, or similar protocols, and familiarity with secure coding practices and common cryptographic pitfalls. Ability to work from our San Jose office (in a hybrid or onsite model as defined by eBay policy) and to collaborate optimally across security, platform, and infrastructure teams in a fast-paced environment.#LI-BB 1 Additional Details. The base pay range for this position is expected in the range below:$172,000 - $229,600