About the Company:  Shardeum is building a layer 1, EVM-based, linearly scalable, smart contract platform that provides low gas fees forever while maintaining true decentralization and solid security through dynamic state sharding. Shardeum aims to be a chain capable of onboarding over a billion people to the crypto revolution, while also democratizing accessibility to decentralization. Shardeum’s mission is supported by prominent Venture Capitalists in the blockchain space, and we are on track to become one of the most widely used and well known smart contract platforms in blockchain history.We encourage you to browse our website, Whitepaper, Discord and YouTube channel to learn more about the project. You can even try downloading our validator software and joining our Testnet. We encourage people of all backgrounds to apply. Your talent and potential is what matters most to us. Shardeum is committed to creating an inclusive culture.About The Role: The Engineering team at Shardeum is responsible for delivering the Shardeum Mainnet and developing critical components such as the smart contract platform, consensus layer, and protocol layer. As part of this team, the SDET (Software Development Engineer in Test) will play a key role in ensuring the quality, reliability, and performance of Shardeum’s decentralized platform through robust test automation, debugging, and validation processes. This role is ideal for engineers who have a passion for test automation, load testing, and identifying root causes of bugs to enhance blockchain performance and scalability. If you’re excited about solving unique challenges in the Web3 space and driving innovation in blockchain testing methodologies, we want to hear from you! What You'll Be Doing:

Analyze bug tickets, debug code, and identify the root cause of errors across the Shardeum platform. Design, develop, and maintain test automation frameworks and reusable test scripts to validate core functionality, including nodes, consensus mechanisms, smart contracts, and blockchain transactions. Utilize cutting edge AI tools to make testing faster and more efficient (Cursor, Github Copilot, Windsurf, Cline, etc..) Develop and execute load testing scripts to validate system performance under high transaction loads and varying node configurations. Create comprehensive test coverage through functional, integration, system, and regression testing while optimizing test suites and identifying performance bottlenecks. Develop end-to-end (E2E) test cases for complex workflows, ensuring reliability of consensus protocols and smart contract execution. Collaborate closely with development teams to integrate testing into CI/CD pipelines, improve testing workflows, and troubleshoot dependency failures. Build and maintain internal tools to improve developer experience, productivity, and test efficiency. Troubleshoot highly complex automated testing failures using industry-standard frameworks and custom tools, working with developers and backend partners to triage issues and improve E2E reliability. Develop monitoring tools and utilities to track blockchain-specific performance metrics and test results. Participate actively in agile ceremonies, including sprint planning, stand-ups, and retrospectives, to drive testing best practices. Continuously research and adopt innovative tools, frameworks, and testing methodologies to improve quality, scalability, and efficiency of testing processes.

What We're Looking For:

5+ years of experience in Software Engineering or SDET roles with a focus on testing. Proficiency in programming languages like TypeScript/JavaScript and Node.js, with the ability to develop robust and reusable test scripts. Ability/desire to write Unit Tests in TypeScript/JavaScript and Node.js Proven ability to analyze and debug complex codebases, troubleshoot multi-tier web architecture issues, and identify root causes of failures. Experience integrating automated tests into CI/CD workflows (e.g., GitHub Actions, Jenkins). Expertise in defining and implementing release, regression, and smoke testing strategies for large, multi-team applications. Experience with white-box testing methodologies to ensure deep validation of internal components. Strong problem-solving and critical-thinking skills, particularly in analyzing blockchain-specific issues. You have a tester mindset, are curious, and excel at designing innovative and interesting test scenarios. You are creative in applying proven tools/test frameworks as well as crafting new solutions to challenging problems. Knowledge of Agile/Scrum methodologies and the software development lifecycle. Excellent verbal and written communication skills for clear bug reporting and collaboration across teams.

We'd Love If You Have:

Experience with testing decentralized applications (dApps), consensus protocols, or blockchain platforms. Experience in running nodes within blockchain networks and monitoring performance metrics. Familiarity with blockchain tools and frameworks (e.g., Web3.js, Hardhat, Truffle). Hands-on knowledge and experience with AI tools (Cursor, Github Copilot, Windsurf, Cline, etc...), and the ability to demonstrate how you utilize them in your day to day. Contributions to open-source projects related to testing, automation, or blockchain. A passion for emerging technologies, including Web3, AI, and distributed systems. Experience using or contributing to the Shardeum open-source repos. Familiarity with blockchain performance benchmarks and profiling tools. Knowledge of the Bitcoin and Ethereum whitepapers.

We are building the infrastructure for Web 3.0. It's going to be a rollercoaster ride but promises to be fun.

Apply Now:

Apply Now:

Protofire is looking for an enthusiastic Middle/Senior Fullstack Developer who is deeply passionate about the Web3 space. Join our dynamic team engaged in projects with renowned companies such as (ex. Gnosis) Safe, Uniswap, Compound, Moonbeam, Cronos, Harmony, Oasis, Wemade, ImmutableX, Optimism, zkSync, zkScroll, Lido, ETH Foundation and over 20 others.

How you will make an impact:

• Develop both back-end and front-end web services and products across various blockchains and ecosystems, primarily EVM-compatible, catering to millions of web3 users.
• Gain a comprehensive understanding of the business aspects of projects and enhance them with innovative features and functionalities.
• Engage in effective communication with network/platform owners and the ecosystem community, actively contributing to the broader adoption of web3.
• Contribute significantly to the open-source community.

What you need to succeed:

• 5+ years of experience in software engineering.
• 3+ years of commercial development experience with JS/Typescript, and any (the more the better) of the following: Node.JS, Go, Rust, Python.
• Proficiency with Postgress, MongoDB and/or nonSQL.
• Knowledge about how a blockchain works, preferably Ethereum is a must.
• Experience with Solidity.
• Experience with some of the following libraries and utils: hardhat, web3.js, ethers.js, web3.py, storybook, etc.
• Experience in AWS.

• A desire to keep up with blockchain technology trends, readiness to research new, and a real interest in decentralization.

Apply Now:

About CoW DAO

CoW DAO is on a mission to protect Ethereum users from the dangers of DeFi. It does this by supporting the development of CoW Protocol, CoW Swap, MEV Blocker, and CoW AMM, and by funding values-aligned projects through the CoW Grants Program.

CoW Protocol is the second-largest DEX aggregator by monthly volume and the first-largest intents-based exchange. MEV Blocker is currently involved in ~4% of all Ethereum transactions, making it the category leader. CoW AMM is the only live AMM that protects LPs from LVR (loss-versus rebalancing).

As a member of CoW DAO’s core team, you will have the opportunity to shape these essential products, and contribute to the Ethereum ecosystem more broadly.

About the role

Location: We are a fully remote team, and although we hire almost globally, there is a preference for this role to be based in Europe or remote +/- 4 hours CEST time_

Please note we’re not hiring from the US, Australia, or New Zealand

Position: Full-time contractor

We’re on the lookout for a Smart Contract Engineer to join our team. If you’re passionate about blockchain tech, love solving complex problems, and thrive on ownership, we’d love to hear from you. We’ve got a packed roadmap full of exciting projects, and we’re all about building innovative, solid, and high-performance solutions as we grow

What you will do

• Build new features: work on new CoW Protocol features by developing new smart contracts and laying out support for them in our off-chain infrastructure
• Review protocol integrations: advise third parties on how to work with CoW Protocol, write grant proposals and support grantees in their execution
• Foster decentralization: contribute to designing the next version of CoW Protocol, in the spirit of removing central authorities and building trust through verifiable execution
• Contribute to the upkeep of the protocol: investigate suspicious transactions, detect on-chain misbehavior, support CoW DAO governance by participating in the discussion through its formal proposal process (CIPs)
• Maintainable code: collaborative coding through code review, internal feature discussion, full testing coverage, CI, public development process on GitHub
• Collaborating with a remote team, sharing feedback, and debugging

Tech stack you’ll be in contact with

• Smart contracts: Solidity, Foundry, rarely Hardhat
• Back-end contract services: Rust, Kubernetes
• Debugging and alerting: Tenderly, Grafana, Elasticsearch
• Data analysis: Python, Dune Analytics
• Governance: Safe Multisig, Snapshot
• Communication: GitHub, Slack, Notion, Zoom, Google Docs
• Supported chains: Ethreum, Arbitrum, Gnosis Chain, Base

Who you are

• Has solid Solidity expertise – with experience working on EVM-compatible chains
• Is skilled in Rust or Python – Rust is preferred, but Python works too as long as you’re open to learning Rust
• Delivers results – you have a proven history of writing high-quality, functional, and reliable code
• Works well remotely – async communication, detailed code reviews, and team collaboration are second nature to you
• Excels at problem-solving – you can tackle challenges with creativity and efficiency
• Takes ownership – you’re proactive and see things through to the end

A bonus

• Familiarity with the DeFi ecosystem
• Experience contributing to or managing open-source project

What we can offer

• Flexible work environment: Join our hub in Lisbon or work remotely
• Token plan: Have a stake in our mission and shape the future of CoW DAO
• Periodic gatherings: Enjoy opportunities to connect with the rest of the team through regular trips
• Conference allocation: Stay up-to-date with ecosystem advancements using our conference budget
• Learning budget: Use our learning budget to support your higher ambitions
• Hardware budget: Take advantage of a hardware budget for acquiring necessary equipment
• Make an impact: You are joining a startup where you can make a huge difference. Your work matters!
• Flat hierarchies mean fewer processes and bureaucracy - see more of your ideas come to life!
• Flexible work and vacation times: Prioritize work-life balance through our robust flexible work policy and vacation allowance
• Growth: If you’re someone who loves taking the initiative and getting things done, CoW offers lots of opportunities for your individual growth

Referral Program

Earn 5.000 USDC or USD with the refer-to-earn program. More details here.

Culture

Life within the CoW Protocol is an incredible adventure! We take pride in our collaborative approach, embracing autonomy and fostering a culture of big thinking and continuous growth. We value impact, ownership, simplicity, and team spirit. Plus, we’re all about feedback, coming together, and enjoying the journey along the way!

At CoW Protocol, we strive to create a space where everyone feels included and empowered. We believe that our products and services benefit from our diverse backgrounds and experiences. All qualified applicants are considered for positions regardless of race, ethnic origin, age, religion or belief, marital status, gender identification, sexual orientation, or physical ability.

About the company and the project:

Dynamic IT software development company specializing in IT development and project management services mostly in web3 industry in the search for aBlockchain Developer. We support digital asset exchanges, copy trading platforms, B2Copy platforms, gaming applications, Web3, and blockchain applications, delivering high-quality, scalable, and secure solutions.

Your tasks on the position:

• Develop, test, and deploy secure and efficient smart contracts using Solidity
• Design and implement blockchain architecture and infrastructure for various use cases
• Write clean, reusable, and well-documented code following industry best practices
• Collaborate with front-end and back-end developers to integrate blockchain functionality with applications
• Conduct rigorous testing and debugging to ensure the security and functionality of smart contracts
• Stay up to date with the latest trends and advancements in blockchain technology
• Provide technical insights and recommendations for blockchain solutions

Requirements:

• 3+ years of experience in blockchain development with a strong focus on smart contracts
• Demonstrated ability to write secure, gas-efficient, and optimized smart contracts
• Hands-on experience with blockchain frameworks like Ethereum, Polygon, or other EVM-compatible chains
• Deep understanding of Layer 2 blockchain architectures (e.g., rollups, zkEVMs, optimistic rollups) — including bridging, state commitment, and fraud/validity proofs
• Solid grasp of blockchain security best practices (e.g., reentrancy, access control, gas efficiency, upgradability patterns)
• Ability to design scalable on-chain/off-chain architectures, including interaction with relayers, oracles, and decentralized storage
• Strong understanding of blockchain concepts, including consensus algorithms, token standards (ERC-20, ERC-721, ERC-1155), and decentralized applications (dApps)
• Familiarity with tools like Truffle, Hardhat, Remix, and Ganache
• Proficient in programming languages such as JavaScript, TypeScript, or Python for blockchain integration
• Experience with version control systems like Git
• English С1+

Will be an advantage:

• Experience with DeFi protocols, NFTs, or Web3 development, ideally with DePin too
• Familiarity with layer-2 scaling solutions and cross-chain communication protocols
• Knowledge of Docker, Kubernetes, or similar container orchestration tools
• Exposure to cloud platforms such as AWS, Azure, or Google Cloud
• Participation in open-source blockchain projects or contributions to the blockchain community

Benefits:

• Regular salary increases
• Career growth possible faster than in different companies
• Paid sick leave
• Medical insurance
• Residential UAE visa

Apply Now: