Bitcoin 4 Open Source

Free technical Bitcoin training program for developers

Accept the challenge Learn about the residencies
Developer working on Bitcoin

B4OS offers specialized learning paths, allowing devs to focus on the areas of highest demand

Open source and freedom

Contribute to open source like the leaders of Linux, Google and Silicon Valley. Join the 5% that creates 95% of the world's code.

Awaken your potential

Accept the challenge and master the Bitcoin protocol. Be part of an elite training and start contributing to Bitcoin and Lightning.

Networking and community

Connect with developers and experts from around the world. Open the door to unique technical and professional opportunities in Bitcoin.

B4OS 2024 WAS A SUCCESS!

B4OS 2024 Graduates: building Bitcoin Open Source full-time

Fernando Ledesma

Fernando Ledesma

SimLN & LNDK

B4OS residencies

B4OS offers specialized Bitcoin residencies for developers from Latin America, the Caribbean, and Spain. Unleash your full potential with B4OS: the best devs are selected to attend residencies with mentoring and master classes with expenses covered. To participate, it is essential to register and complete the programming challenges (PoW).

South America

Duration: 2 weeks
Start: Feb. 2026
Location: Florianópolis, Brazil

Intensive program for senior developers from South American countries with specialized training in Bitcoin Core and Lightning Network.

Europe

Duration: 2 weekends
Start: Date to be defined
Location: Valencia, Spain

Intensive residency in Europe, focused on networking and collaboration with the Spanish Bitcoin ecosystem.

Central America

Duration: 1 full year
Start: Date to be defined
Location: El Salvador or Costa Rica

Special program that includes paid full-time work in Central America.

North America I

Duration: 8 weeks
Start: 15 Oct. - Dec. 2025
Location: Guadalajara, Mexico

Internship for developers at the Bitcoin House Guadalajara.

North America II

Duration: 6 weeks
Start: Oct 15 - Nov 2026
Location: Mexico City

Exclusive for program grantees, focused on advanced projects and specialized mentoring.

* Dates may be subject to change. Selected participants will be notified in advance.

B4OS Timeline

Learn about the important dates of the B4OS 2025–2026 program

Aug 11 - Sept 15, 2025

Registration

Registration of participants for the B4OS 2025–2026 program.

SEPT 15, 2025

B4OS Challenges

Let's see your programming level and Bitcoin knowledge. This stage is an asynchronous phase on Discord without classes or mentoring, but with community support.

🏆 The best developers move on to the next stage.
Rookie award: $300 USD for the best code from new developers who have never participated in B4OS, BOSS, or other programs.

OCT 10, 2025

Application review

Selection of developers.

OCT 12, 2025

Guadalajara, Mexico selection

Selection of 3 junior developers for the program in Guadalajara, Mexico.

OCT 15, 2025

Division into tracks

  • Bitcoin Core Protocol Developer
  • Lightning Network Protocol Developer
  • Application Developer

From October 15, 2025 to February 2026: portfolio building and FOSS contribution. Seminars, working groups, bitdevs, and meetups (5 months online).

DEC 2025

South America residency selection

Evaluation based on Proof of Work in Open Source projects and course participation. Both routes merge and continue working on projects.

In exceptional cases, developers may also be selected in January.

FEB-MAR 2026

South America in-person residency

2-week immersive experience in Florianópolis, Brazil. Direct work with mentors and peers on high-impact projects.

APR 2026

Assignment of new grantees

Selection process and funding allocation for new program beneficiaries.

Ready to join B4OS 2025?

The B4OS 2025 program is open to senior developers from Latin America, the Caribbean, and Spain. The registration process is completely free.

Application requirements:

  • Software development experience (2+ years)
  • Solid knowledge in languages such as C++, Rust, Python or JavaScript
  • Genuine interest in contributing to the Bitcoin open source ecosystem
  • Availability to invest 5 to 10 hours weekly
  • Resilience to complete the entire program
  • Proficiency in Spanish to actively participate in the program
Registration until: September 15, 2025

B4OS 2025 registration form

You can use your real name or a pseudonym
Double-check your email, we will use it to communicate with you
Select the country where you currently reside
Your current city of residence
Select the language where you feel most productive
Indicate what other languages and technologies you master
Share your GitHub profile or portfolio
We're interested in knowing what specific aspects of the Bitcoin ecosystem you're passionate about (Privacy, Security, Censorship resistance, Decentralization, etc.).
Tell us how you heard about us or through which channel you found us
You must accept the terms to continue

B4OS Program benefits

Discover everything you get by participating in the most comprehensive Bitcoin training program

Open source and Bitcoin training

Access to exclusive content and top-tier technical training in Bitcoin Core and FOSS technologies.

Solid international portfolio

Opportunity to build a portfolio and resume with real contributions to open source projects.

Networking

Connect with a global community of developers, entrepreneurs, and experts from the Bitcoin ecosystem worldwide.

Expert mentorship

Learning and guidance from respected leaders in the Bitcoin ecosystem.

Hacker residencies

In-person residencies for developers with Bitcoin ecosystem experts to develop your full potential.

Micro-grants

Possibility of obtaining financial support to dedicate part-time to FOSS development.

Language and programming training

English and software development classes for grantees.

Full-time jobs

Full-time jobs through grants to work on Bitcoin Open Source.

International conferences

Scholarships to attend international conferences on Bitcoin and ecosystem technologies.

Frequently Asked Questions

Yes, B4OS is 100% free. There are no registration fees, paid materials, or hidden costs of any kind. The program is funded by the Satoshi Library to make professional-quality Bitcoin education accessible to Spanish-speaking developers.

Absolutely. All code developed as part of the B4OS program is open source and follows FOSS principles. Participants contribute to real open source projects in the Bitcoin ecosystem, including Bitcoin Core and Lightning Network.

B4OS focuses on Bitcoin Core and Lightning Network development. You'll learn P2P architecture, transaction validation, payment channels, and contribute to real projects. We only cover Bitcoin and its ecosystem.

You don't need Bitcoin experience, but you do need solid programming knowledge. You should have experience with at least one language (Python, C++, Rust, JavaScript), Git, and command line. We'll teach you all the Bitcoin-specific content from scratch.

No, attending the residency is not mandatory. If you attend, you'll have the opportunity to meet other participants and mentors in person, work as a team, and learn from them.

We recommend 5-10 hours weekly during the program's duration. This will be distributed across time for Socratic seminars, preparatory readings, challenges, and development practice hours.

There will always be individual tasks during the program, whether research work, development, or code challenge submissions. If you're actively working on a specific project, you'll have the freedom to specialize, but you won't have the freedom to not work on a project.

Yes, after the first 5 weeks you can specialize by choosing between: Bitcoin Core Protocol Development, Lightning Network Development, or Application Development. Your mentor will help you choose according to your professional interests.

Activities and challenges are primarily done individually, but there are occasions when they will be done in groups. If you have questions, you can contact your mentor or the community in the Discord channel.

We do not record the seminars to maintain a safe and private learning environment. Instead, we provide detailed post-session summaries, supplementary study materials, and make-up sessions for special cases.

We will provide the necessary environments to work on the various projects that will be developed during the program. If you need to install any tools locally, we will do it together.

Tangible and verifiable achievements: Minimum of 3 accepted contributions to Bitcoin Core or Lightning Network, a functional personal project, direct connections with senior Bitcoin developers, and a verifiable certificate with your specific contributions.

Direct partnerships with Bitcoin companies: Guaranteed interviews for the top 20% of graduates, exclusive job board for students, personal references from mentors, and networking events with Bitcoin recruiters.

There are no geographic restrictions. B4OS is open to developers from any country who speak Spanish. Minimum age: 18 years. Schedules are coordinated considering the diversity of time zones of the participants.

Multiple channels available: Main email hola@b4os.dev, Discord community for direct chat, GitHub Issues for technical reports, and regular feedback sessions during the program.

Alliances

Bitcoin for Open Source would not be possible without the support of our allies.

Strategic allies

Leading Bitcoin organization in Argentina.

R&D lab focused on Bitcoin Core and Lightning.

Join our team

We are building the future of Bitcoin technical education.
We are looking for passionate people who share our vision of training the next generation of talent in the Bitcoin ecosystem: technical education and specialized entrepreneurship

100% remote

We work from anywhere in the world. Freedom is part of our core values.

Real technical impact

You contribute to the training of specialists in development and technical education who directly impact the Bitcoin ecosystem.

Accelerated growth

Join a company in expansion in the most innovative sector of the moment.

Interested in joining?

We currently have open positions. Check out our available opportunities.

View opportunities