Yes, Java only. Rust as well, but that is likely only for a limited project.

Here the assignment for candidates: Trade protocol analysis, design and implementation
https://github.com/bisq-network/bisq2/discussions/3200

Yes, all caution is justified. See in the blog post that the same email address is used. This should serve enough to verify that it comes genuinely from Bisq.

Payment depends on qualification. Up to 16 000 USD is not unusual for Bisq developers.

See past contribution requests:
https://github.com/bisq-network/compensation/issues?q=is%3Aissue%20state%3Aclosed

Bisq is not a company and does not have official email.
Here is the listing on the Bisq webpage: https://bisq.network/blog/bisq-needs-senior-java-developers/

Bisq, a decentralized, open-source peer-to-peer Bitcoin exchange, is looking for experienced and self-driven Senior Java Developers to help build the future of financial sovereignty. We operate without project managers, embrace open-source collaboration, and focus on security, privacy, and decentralization.

What You’ll Do

- Contribute to the development of Bisq 2, the next iteration of our exchange.
- Design and implement key features within a large and complex Java codebase.
- Work on new trade protocols, peer-to-peer networking, cryptography, and decentralized exchange infrastructure.
- Solve challenging problems in privacy-focused and decentralized systems.
- Engage with the open-source community, participate in discussions, and review contributions.

Who You Are

- Proficient in Java, with extensive experience in high-performance and secure applications.
- A self-managed engineer who thrives in independent, asynchronous workflows.
- Comfortable with reading, understanding, and improving large, complex codebases.
- Have a strong grasp of cryptography, distributed systems, and P2P networks.
- Security- and privacy-focused—you think deeply about system security, attack vectors, and data privacy.
- Quick learner, capable of becoming productive in a new environment without extensive guidance.
- Available full-time.

Bonus Points for Experience In:

- Bitcoin Development (MuSig, BDK, PSBTs, UTXO management)
- Tor, I2P
- Cryptography
- Low-level networking, P2P networks, distributed systems
- User Experience (UX) with JavaFX
- Rust (used in our new MuSig based trade protocol)
- Kotlin KMP (Mobile Development)
- Lightning Network
- Monero, Liquid (Sidechains)
- Contributions to Open-Source Projects

Why Join Bisq?

- 100% Remote—work from anywhere in the world.
- No geographic restrictions.
- No micromanagement—work independently with meaningful impact.
- Contribute on Bitcoin's core mission—build censorship-resistant Bitcoin infrastructure.
- Compensation based on international market rates.

How to Apply?

If you’re passionate about Bitcoin, privacy, and open-source development, we’d love to hear from you.

- Matrix Bisq 2 Dev Channel: https://matrix.to/#/#bisq2-dev:matrix.org
- Email: bisq_head_hunter@proton.me

Learn More About Bisq

- Website: https://bisq.network
- GitHub: https://github.com/bisq-network

Bisq, a decentralized, open-source peer-to-peer Bitcoin exchange, is looking for experienced and self-driven Senior Java Developers to help build the future of financial sovereignty. We operate without project managers, embrace open-source collaboration, and focus on security, privacy, and decentralization.

What You’ll Do

- Contribute to the development of Bisq 2, the next iteration of our exchange.
- Design and implement key features within a large and complex Java codebase.
- Work on new trade protocols, peer-to-peer networking, cryptography, and decentralized exchange infrastructure.
- Solve challenging problems in privacy-focused and decentralized systems.
- Engage with the open-source community, participate in discussions, and review contributions.

Who You Are

- Proficient in Java, with extensive experience in high-performance and secure applications.
- A self-managed engineer who thrives in independent, asynchronous workflows.
- Comfortable with reading, understanding, and improving large, complex codebases.
- Have a strong grasp of cryptography, distributed systems, and P2P networks.
- Security- and privacy-focused—you think deeply about system security, attack vectors, and data privacy.
- Quick learner, capable of becoming productive in a new environment without extensive guidance.
- Available full-time.

Bonus Points for Experience In:

- Bitcoin Development (MuSig, BDK, PSBTs, UTXO management)
- Tor, I2P
- Cryptography
- Low-level networking, P2P networks, distributed systems
- User Experience (UX) with JavaFX
- Rust (used in our new MuSig based trade protocol)
- Kotlin KMP (Mobile Development)
- Lightning Network
- Monero, Liquid (Sidechains)
- Contributions to Open-Source Projects

Why Join Bisq?

- 100% Remote—work from anywhere in the world.
- No geographic restrictions.
- No micromanagement—work independently with meaningful impact.
- Contribute on Bitcoin's core mission—build censorship-resistant Bitcoin infrastructure.
- Compensation based on international market rates.

How to Apply?

If you’re passionate about Bitcoin, privacy, and open-source development, we’d love to hear from you.

- Matrix Bisq 2 Dev Channel: https://matrix.to/#/#bisq2-dev:matrix.org
- Email: bisq_head_hunter@proton.me

Learn More About Bisq

- Website: https://bisq.network
- GitHub: https://github.com/bisq-network

Bisq, a decentralized, open-source peer-to-peer Bitcoin exchange, is looking for experienced and self-driven Senior Java Developers to help build the future of financial sovereignty. We operate without project managers, embrace open-source collaboration, and focus on security, privacy, and decentralization.
What You’ll Do

- Contribute to the development of Bisq 2, the next iteration of our exchange.
- Design and implement key features within a large and complex Java codebase.
- Work on new trade protocols, peer-to-peer networking, cryptography, and decentralized exchange infrastructure.
- Solve challenging problems in privacy-focused and decentralized systems.
- Engage with the open-source community, participate in discussions, and review contributions.

Who You Are

- Proficient in Java, with extensive experience in high-performance and secure applications.
- A self-managed engineer who thrives in independent, asynchronous workflows.
- Comfortable with reading, understanding, and improving large, complex codebases.
- Have a strong grasp of cryptography, distributed systems, and P2P networks.
- Security- and privacy-focused—you think deeply about system security, attack vectors, and data privacy.
- Quick learner, capable of becoming productive in a new environment without extensive guidance.
- Available full-time.

Bonus Points for Experience In:

- Bitcoin Development (MuSig, BDK, PSBTs, UTXO management)
- Tor, I2P
- Cryptography
- Low-level networking, P2P networks, distributed systems
- User Experience (UX) with JavaFX
- Rust (used in our new MuSig based trade protocol)
- Kotlin KMP (Mobile Development)
- Lightning Network
- Monero, Liquid (Sidechains)
- Contributions to Open-Source Projects

Why Join Bisq?

- 100% Remote—work from anywhere in the world.
- No geographic restrictions.
- No micromanagement—work independently with meaningful impact.
- Contribute on Bitcoin's core mission—build censorship-resistant Bitcoin infrastructure.
- Compensation based on international market rates.

How to Apply?

If you’re passionate about Bitcoin, privacy, and open-source development, we’d love to hear from you.

- Matrix Bisq 2 Dev Channel: https://matrix.to/#/#bisq2-dev:matrix.org
- Email: bisq_head_hunter@proton.me

Learn More About Bisq

- Website: https://bisq.network
- GitHub: https://github.com/bisq-network