At a Glance
- Tasks: Design and implement blockchain services and smart contracts for real-world applications.
- Company: Join a forward-thinking company at the forefront of Web3 and sustainability tech.
- Benefits: Competitive salary, flexible working options, and opportunities for professional growth.
- Other info: Work in a dynamic environment focused on innovative financial solutions and carbon markets.
- Why this job: Make a tangible impact in the evolving world of blockchain and sustainability.
- Qualifications: Experience with Ethereum, Solidity, NodeJS, and modern JavaScript; teamwork skills essential.
The predicted salary is between 34000 - 69000 £ per year.
We are looking for strong experience with Ethereum and Solidity, including building and deploying smart contracts in production or in advanced side projects. We need a solid understanding of core Web3 patterns, including transactions, events, wallets, token standards, and common security pitfalls. We expect you to write clean code, break down complex problems, and collaborate effectively with product and engineering teams. We require confidence with NodeJS and modern JavaScript standards such as ES6 and ES7. We would like experience with ReactJS or VueJS to support user flows when needed.
Nice to have: experience with Hyperledger Besu, permissioned network design, and consensus configuration. Exposure to regulated or evidence-heavy environments, carbon markets, ESG data, or sustainability platforms. Experience with Web3 tooling, testing, and secure smart contract development practices.
Responsibilities:
- Design and implement critical components of blockchain services and the smart contract ecosystem.
- Build token workflows, including minting, transfer, verification, and retirement mechanics.
- Implement token standards such as ERC 20 and ERC 1155 with structured metadata like project ID, vintage year, and verification body.
- Help set up and operate multi-node Besu networks using IBFT 2.0 or QBFT consensus for permissioned programmes.
- Deliver repeatable testnet deployments.
- Build and integrate APIs that connect on-chain activity with off‑chain systems, including MRV‑style measurement, reporting, and verification feeds.
- Produce clear documentation that supports security review, audit readiness, and ongoing team maintenance of the solution.
Technologies: Blockchain, ES6, Ethereum, Support, JavaScript, Network, NodeJS, Security, Solidity, Web3, Vue.
We are working on the intersection of Web3, financial market infrastructure, and sustainability tech, building production‑grade blockchain solutions for real‑world adoption rather than demos. Depending on the role, you could be based in Central London helping us decentralise parts of traditional financial services with an Ethereum platform, or work remotely on a clean technology programme delivering carbon offset tokenisation using Hyperledger Besu, smart contracts, APIs, and audit‑ready delivery. We value practical, engineering‑led delivery and we are building solutions for digital assets infrastructure, tokenisation, and sustainability use cases such as carbon credit issuance and retirement.
Blockchain Developer employer: Sivara GmbH
As a leading innovator at the intersection of Web3 and sustainability, we offer Blockchain Developers an exciting opportunity to work on impactful projects that decentralise traditional financial services and promote carbon offset initiatives. Our collaborative work culture fosters continuous learning and growth, with access to cutting-edge technologies and a commitment to engineering excellence. Located in Central London, we provide a dynamic environment where your contributions directly influence real-world applications, making this an ideal place for those seeking meaningful and rewarding employment.
