Kotlin Jobs in Web3

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:

• Design, build, and maintain XMTP, our E2EE messaging protocol. Example projects include:

  • Extending our encrypted group chat protocol to work for 1:1 conversations.

  • Determining how to share user state between devices in a privacy-preserving way.

  • Designing a protocol to share whether or not a message was sent by a given user with third party servers in a trust-minimized way

• Collaborate closely with other engineers, developers, and stakeholders to help our small team build with confidence and deliver with velocity.

• Engage in open-source communities and events, representing Ephemera effectively in public forums.

• Evaluate and recommend trade-offs in our development plans and system design, considering factors such as security, scalability, efficiency, and cost.

Your experience:

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

• Expertise in Rust and at least one of the following: Kotlin, Swift, C++.

• Extensive experience designing, developing, and maintaining communication protocols with an emphasis on performance, scalability, and security. A well-rounded, "T-shaped" expertise profile is preferred.

• Understanding of encryption algorithms (e.g., AES, RSA), key exchange protocols (e.g., Diffie-Hellman), and secure messaging protocols (e.g., Signal Protocol, PGP).

• 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 solve them.

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

• You love to learn, are not afraid of changing your opinion or being wrong.

Benefits:

• Competitive compensation package, Base + Equity.

• Salary range between $200k-$250k 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 Life>

• 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 try to keep our team small and focus on working with the best people in the world. We are looking for people who can show the incredible things they have worked on and have built and worked on similar technology before. Not because we want to limit who can work here, but because to build something as impactful as XMTP, it requires insanely specific skills and knowledge from the team working here.