Staff Software Engineer (Messaging Protocol) - North America

Join Ephemera, build the future of onchain messaging.

We are currently hiring a Staff level Software Engineer focused on building and maintaining XMTP.

What you’ll be working on:

• Build and maintain XMTP’s mobile SDKs, designing and implementing Rust-to-mobile bindings for high-performance, reliable developer experiences across iOS, Android, and React Native.

• Advance the encrypted messaging protocol (built on Rust and OpenMLS), from multi-device sync and performant content types to scaling from hundreds to tens of thousands of participants.

• Collaborate with teammates to design systems, evaluate trade-offs, and deliver improvements, balancing security, scalability, and efficiency.

• Engage with the open source community, ensuring XMTP SDKs are intuitive, well-supported, and empowering the next generation of privacy-preserving apps.

Your experience:

• Minimum of 10+ years of professional experience as a staff-level software engineer.

• Expertise in mobile development with one or more of Kotlin, Swift, React Native, or C++, including delivering production-ready SDKs or apps.

• Solid experience with Rust, or a strong interest in learning Rust and building Rust-to-mobile bindings.

• Experience building and maintaining communication protocols, SDKs, or developer-facing APIs with an emphasis on performance, scalability, and security. A well-rounded, "T-shaped" expertise profile is preferred.

• Bonus points if you have prior experience with Messaging Layer Security.

• A proven aptitude for adversarial systems design, including identifying and mitigating potential security risks.

• Prior involvement in open source SDK projects and public communications.

Nice-to-Have’s:

• Experience with large-scale distributed database systems.

• Experience with smart contract development, web3 technologies, and/or protocol mechanism design.

• Familiarity with standards such as ISO 27001, NIST, GDPR, and HIPAA.

• Experience in implementing and adhering to security compliance requirements.

• Interest in or prior experience with privacy-preserving cryptographic technologies, or with zero-knowledge cryptography.

• Experience contributing to a Layer 1 blockchain.

About you:

• You are passionate about decentralized technology and believe in an onchain future.

• You love to win and are fueled by solving hard problems.

• You are self-directed, see opportunities, and are inspired by challenges and helping to solve them.

• You have a small team mindset and are focused on where you can have the greatest impact.

• You love to learn and are not afraid to change your opinion or admit to being wrong.

Benefits:

• Competitive compensation package, Base + Equity.

• Salary range between $230k-$265k base range (depending on experience + location).

• Remote-first environment with semi-yearly gatherings to connect IRL.

• Fully paid Medical, Dental, Vision insurance in the US.

• Parental Leave.

• IT Equipment and WFH setup.

• Monthly Wellness and Lifestyle stipend.

• Personal assistant.

• Unlimited time off

Culture:

Ephemera isn’t for those merely exploring or curious about Web3, or those needing daily direction. It’s for the committed—those devoted to decentralized technology and an onchain future, with a championship mindset, ready to win alongside the best.

Our shared belief fuels our success, and our values steer our decisions. Our culture guide is a transparent look into how we operate.

This is a different type of company. Both in how we work and what we work on. We intentionally keep our team small and focus on working with the best people in the world. We’re looking for people whose track record demonstrates the ability to work effectively with our technology stack to take on the difficult but deeply impactful challenge of building XMTP.