APPLICATIONS FOR THE 2026 ₿OSS CHALLENGE ARE NOW OPENApply Now →

START YOURCAREER INBITCOIN OPEN SOURCE

The ₿OSS Challenge is a Chaincode Labs initiative for coders serious about beginning a career in bitcoin open source software

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About the Challenge

It's no secret that getting started in ₿OSS (Bitcoin Open Source Software) can be difficult. Sometimes it's not obvious where to begin, and other times it takes an extra nudge. No matter the situation, the ₿OSS Challenge is ready to tackle obstacles like these by providing guidance and scaffolding for the journey.

At the heart of the challenge is a set of programming exercises and hands-on activities spanning the course of a month. Once that month is complete, participants that are ready to continue the adventure have the opportunity to extend the program for two additional months.

How It Works

A structured 3-month journey from learning to contributing

Month One

Foundation & Core Learning

Chaincode curates each cohort, arranges curriculum, and provides ongoing support throughout the program. You will be expected to prep for a minimum 10 hours per week. Outside of the first week, there are no scheduled calls. This program will be taught and mentored by ₿OSS contributors that have stood in your shoes. Throughout the week, there will be async chat discussions and support. If you are willing to do the work, we'll give you what you need to get to where you want to go.

Stage 2 - Advanced Programs & Partnerships

2-3

Months 2 & 3

Advanced Programs & Partnerships

You will have the opportunity to participate in a program with a partner organization. Chaincode will also run a seminar and provide a list of supplemental resources. Advanced participants may be selected for additional opportunities.

Your Journey

Beyond the Program

The journey to becoming a full-time ₿OSS contributor is long, winding, and different for everybody. It is not a straight path. This challenge is not only designed to give you some supports along the way, but to foster the proactive, self-starter spirit that is required in open source. Join the challenge and see how far you can go!

₿OSS Alumni

Meet the talented developers who have completed the challenge and are now contributing to bitcoin open source projects

2025

₿OSS Alumni

Sangbida

Funded by Blockstream to contribute to Core Lightning

Daniel

Funded by ANNOUNCED SOON to contribute to Bitcoin Core

Ben

Funded by Maelstrom to contribute to PayJoin

Zealsham

Funded by ANNOUNCED SOON to contribute to PayJoin

Ron

Funded by Maelstrom to contribute to Silent Payments

Beulah

Funded by ANNOUNCED SOON to contribute to FROST

Rita

Funded by ₿trust to contribute to LDK Node

Chuks

Funded by ₿trust to contribute to LDK Node

Elnosh

Funded by OpenSats and Chaincode to contribute to LDK and Channel Jamming Research

2024

₿OSS Alumni

Nick

Funded by Spiral to contribute to Rust Bitcoin

Rob

Funded by BDK Foundation, OpenSats, and 2140 to contribute to BDK and kyoto

David

Funded by OpenSats and localhost to contribute to Bitcoin Core

Rkrux

Funded by Maelstrom to contribute to Bitcoin Core

Hodlinator

Funded by OpenSats to contribute to Bitcoin Core

Tdb3

Funded by OpenSats to contribute to Bitcoin Core

Spacebear

Funded by Spiral to contribute to PayJoin

Marco

Funded by Brink to contribute to Bitcoin Core

Learning Resources

Free, world-class content to accelerate your Bitcoin journey

Self Paced Seminars

Materials are available for anyone to use with readings and discussion questions on various Bitcoin and Lightning topics.

Check it out

Onboarding to Bitcoin Core

Covering both the technical components such as, architecture, consensus, validation, the wallet, P2P, and script, and also introduces the under-documented social aspects like PR etiquette and the decentralized development process.

Check it out

Bitcoin Development Philosophy

A guide for Bitcoin developers who already understand the basics of concepts and processes such as Proof-of-Work, block building, and the transaction life cycle, and who want to level up by gaining a deeper understanding of Bitcoin's design trade-offs and philosophy.

Check it out

Rust for Bitcoiners

Master the fundamentals of Rust and bitcoin. Start your journey to becoming a bitcoin rust contributor.

Check it out

About Chaincode

Chaincode Labs is a Bitcoin research and development center based in New York City. We focus on the development of the bitcoin network and related technologies. A critical part of our work is creating a space for those seeking a solid foundation with which to contribute to the bitcoin ecosystem.

Since 2016, our residency program has helped to train and develop the next generation of Bitcoin and Lightning protocol and application engineers.

Learn.

Contribute.

Get Started.

Apply to the ₿OSS Challenge

consensus/amount.h

static constexpr CAmount COIN = 100000000;
static constexpr CAmount MAX_MONEY = 21000000 * COIN;

chainparams.cpp

const char* pszTimestamp = 
    "The Times 03/Jan/2009 Chancellor on brink "
    "of second bailout for banks";
genesis = CreateGenesisBlock(1231006505, 2083236893, 
                             0x1d00ffff, 1, 50 * COIN);

pow.cpp

bool CheckProofOfWork(uint256 hash, unsigned int nBits) {
    bnTarget.SetCompact(nBits, &fNegative, &fOverflow);
    if (fNegative || bnTarget == 0 || fOverflow)
        return false;
    if (UintToArith256(hash) > bnTarget)
        return false;
    return true;
}

merkletree.cpp

uint256 ComputeMerkleRoot(
    const std::vector<uint256>& leaves,
    bool* mutated) {
    if (leaves.size() == 0) {
        return uint256();
    }
    return ComputeMerkleRootFromBranch(
        leaves, leaves.size(), 0);
}

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₿OSS Challenge