Decentralised Messaging Engineer - Rust in London

Logos is a movement supporting the development of the decentralised web. Logos technologies lay the foundations for a freer internet upon which communities can evolve into network states. Each protocol in the Logos stack seeks to empower its users while upholding civil liberties and fundamental freedoms.

The Logos Messaging team is focused on creating communication infrastructure for a freer internet — permissionless, interoperable, and based on user consent. We're building toward a world where anyone can reach anyone on a network that no single entity controls or can take away. We cannot afford to compromise on Privacy, and "Eventual Decentralisation" is not an option.

Right now we're deep in the hard problems: Bringing decentralised group messaging over MLS to all developers. This is frontier tech work — the protocols we're writing don't have established playbooks, and the tradeoffs we're navigating haven't all been mapped yet.

This is where you come in. We're a small team seeking engineers who have a passion for decentralised chat and who've thought deeply about how these systems work, where they fail, and what it takes to get them right. You'll work directly on our SDK and contribute to the protocols underneath it, with real ownership over work that enables open communication.

• Implement our messaging protocols in our reference SDK, translating protocol specs into reliable, production‑quality Rust.
• Own the API design and developer experience of the SDK surface — abstractions, ergonomics, and developer‑facing documentation.
• Contribute to messaging protocol specifications alongside the team.
• As a member of a small team, you'll wear many hats — picking up problems outside your immediate lane, learning as you go, and growing with the team.
• Write clear technical documentation and participate in async design discussions with collaborators across the project.

Don't worry if you don't meet all of these criteria — we'd still love to hear from you if you think you'd be a great fit. Just explain why in your cover letter.

• Deep familiarity with real‑world instant messaging systems - you've worked on, contributed to, or spent serious time understanding how systems like Signal, Matrix, XMPP, or similar are built, where they make tradeoffs, and where they struggle.
• Experience with decentralised computing - peer‑to‑peer systems, distributed networks, or decentralised application infrastructure.
• Comfort working directly with cryptographic primitives - signatures, ciphers, and key exchanges and an understanding of secure private messaging principles such as forward secrecy, post‑compromise security, and key management.
• Solid Rust experience: comfortable writing reliable, maintainable code in a team setting.
• Previous experience with Web3, blockchains, open protocols, and the values that underpin them.
• A strong alignment to our principles: with Post‑Quantum Cryptography and its application to secure messaging.
• Experience with MLS (Message Layer Security / RFC 9420) or the OpenMLS library specifically.
• You've authored or contributed to an open specification.
• Familiarity with P2P transport layers such as Waku or libp2p.
• Experience working for an open source organisation.
• Comfortable working remotely and asynchronously.

The expected compensation range for this role is negotiable, dependent on how we assess your skills and experience throughout our interview process. We are happy to pay in any mix of fiat/crypto.