Junior Software Engineer
Status
Paris, France
Full time
Hybrid
Compensation is not specified
Role
Software Engineer
Description
We are dedicated to making digital asset accessibility and security mainstream for all individuals. Embrace the opportunity to be part of this impactful mission.
Established in 2014, Ledger serves as the global platform for digital assets and Web3. Ledger Nanos secure over 20% of the world's crypto assets, with a presence in Paris, Vierzon, UK, US, Switzerland, and Singapore, boasting a team of over 500 professionals working on various products and services. These offerings enable secure transactions related to buying, storing, swapping, growing, and managing crypto assets. The Ledger hardware wallets have already amassed over 6 million units sold across 200 countries.
Ledger's values, including Pragmatism, Audacity, Commitment, Trust, and Transparency, are embodied by its team, which shapes the work culture. Experience firsthand accounts of our team members shaping the industry by watching the [linked video].
This role offers the chance to evolve, innovate, face challenges, and contribute significantly to Ledger's goal of securing the digital realm to be more accessible, secure, and user-friendly.
Joining the esteemed Ledger Connectivity Team, you'll become an integral part of enhancing Blockchain integrations in Ledger Live, with a strong focus on continual improvement.
Primary Responsibilities
- Support Connectivity Team: Participate in building and maintaining tools facilitating interaction between Ledger and its ecosystem, such as Wallet Connect integrations, Dapp integrations on Ledger Live, and our Wallet API.
- Enhance JavaScript Proficiency: Strengthen your skills in the JavaScript ecosystem by working with TypeScript, Node.js, and React.
- Collaborate with Diverse Teams: Engage with seasoned professionals and teams to refine our connectivity framework, promoting functional programming principles for a clean, manageable, and effective codebase.
- Immerse Yourself in Blockchain Technology: Develop your knowledge of blockchain technologies with prospects for future roles within our Blockchain Integration Team.
Qualifications
- Coding Enthusiast: Display a keen interest in programming and a solid eagerness to learn and excel in the JavaScript domain.
- Basic JavaScript Tech Experience: Hold some exposure to TypeScript, Node.js, and React through projects, coursework, or internships.
- Curiosity for Functional Programming: Exhibit interest in embracing functional programming concepts and modern design approaches.
- Team Spirit: Demonstrate strong communication skills and effective collaboration within a team setting.
- Agile Methodology Understanding: Basic familiarity with agile work environments and CI/CD processes will be advantageous.
Extra Credit
- Blockchain Enthusiast: Show interest in Web3 and blockchain with exposure to related concepts or the development of Dapps, using libraries like Ethers.js and Wagmi.
- Contributions to Open-Source Projects: Engage in open-source initiatives or coding communities to deepen your expertise.
- Blockchain Standards Knowledge: Possess a general comprehension of blockchain architecture and standards like EVM, Cosmos, Polkadot, or Bitcoin.
Perks
- Equity Sharing: Get the chance to better reap the company's growing success by receiving stock options.
- Flexible Work Policy: Enjoy a hybrid work arrangement.
- Social Events: Participate in the annual company outing - Ledgerdary Days, as well as regular social gatherings, snacks, and beverages.
- Comprehensive Health Benefits: Avail extensive medical, dental, and vision care coverage.
- Personal Development and Well-Being: Access dedicated coaching for personal growth and fitness.
- Vacation: Relish five weeks of paid leave annually, in addition to national holidays and Rest & Relaxation (RTT) days.
- Office Tech Support: Utilize top-tier office equipment and gadgets, including Apple products.
- Transport Reimbursement: Ledger compensates a portion of your preferred mode of transportation.
- Employee Discounts: Benefit from an employee discount available across all our products.
We strongly promote an inclusive workplace representing all individuals with respect to gender, ethnicity, religion, sexual orientation, social status, disability, or age.
Skills Required
Ledger
Website
www.ledger.comCompany size
Not specified
Location
United States
Description
Not specified
Status
Lumixion
DApp & Smart Contract Developer (Vesting Platform)
Full time
Remote
We are looking for a skilled DApp & Smart Contract Developer to enhance and stabilize our client’s crypto vesting platform. You will diagnose existing issues, improve performance, deliver new features, and ensure seamless coordination between smart contracts and the front end.
This role is ideal for someone who thrives in fast-moving environments, values clean and secure code, and understands the nuances of blockchain-based application architecture.
Responsibilities
Diagnose and resolve issues in vesting smart contracts and their front-end integrations.
Implement new features and system enhancements to improve UX and overall platform performance.
Maintain smooth interaction between the web interface and deployed smart contracts.
Conduct testing, audits, and deployments across testnet and mainnet environments.
Optimize contract logic for performance, security, and gas efficiency.
Collaborate with our engineering team to identify pain points and deliver stable, secure solutions.
Requirements
Proven experience building full-stack decentralized applications.
Strong proficiency in Solidity, JavaScript/TypeScript, and modern frameworks (Angular, React, or Vue).
Hands-on experience with Hardhat or Foundry for smart contract development and testing.
Familiarity with Ethers.js or Web3.js for blockchain interaction layers.
Solid understanding of Ethereum, Polygon, or other EVM-compatible chains.
Experience integrating wallets such as MetaMask and managing on-chain/off-chain data flows.
Strong debugging skills, attention to detail, and a security-first mindset.
Nice to Have
Experience with smart contract security audits and gas optimization techniques.
Knowledge of Node.js-based backend services or API integration layers.
Previous experience with vesting, staking, or token distribution mechanisms.
Project Scope
This role supports a short-to-mid-term initiative focused on stabilizing and enhancing an existing crypto vesting platform. High-performing developers may have opportunities for ongoing collaboration across additional blockchain and product engineering projects.
Hiring Process
Technical Assessment - Selected candidates will complete a short, clearly scoped technical exercises designed solely to evaluate coding approach and smart contract knowledge.
CTO interview - A final discussion to evaluate technical reasoning, architectural thinking, and team fit. Successful candidates may receive an offer through Contra following this conversation.
This role is ideal for someone who thrives in fast-moving environments, values clean and secure code, and understands the nuances of blockchain-based application architecture.
Responsibilities
Diagnose and resolve issues in vesting smart contracts and their front-end integrations.
Implement new features and system enhancements to improve UX and overall platform performance.
Maintain smooth interaction between the web interface and deployed smart contracts.
Conduct testing, audits, and deployments across testnet and mainnet environments.
Optimize contract logic for performance, security, and gas efficiency.
Collaborate with our engineering team to identify pain points and deliver stable, secure solutions.
Requirements
Proven experience building full-stack decentralized applications.
Strong proficiency in Solidity, JavaScript/TypeScript, and modern frameworks (Angular, React, or Vue).
Hands-on experience with Hardhat or Foundry for smart contract development and testing.
Familiarity with Ethers.js or Web3.js for blockchain interaction layers.
Solid understanding of Ethereum, Polygon, or other EVM-compatible chains.
Experience integrating wallets such as MetaMask and managing on-chain/off-chain data flows.
Strong debugging skills, attention to detail, and a security-first mindset.
Nice to Have
Experience with smart contract security audits and gas optimization techniques.
Knowledge of Node.js-based backend services or API integration layers.
Previous experience with vesting, staking, or token distribution mechanisms.
Project Scope
This role supports a short-to-mid-term initiative focused on stabilizing and enhancing an existing crypto vesting platform. High-performing developers may have opportunities for ongoing collaboration across additional blockchain and product engineering projects.
Hiring Process
Technical Assessment - Selected candidates will complete a short, clearly scoped technical exercises designed solely to evaluate coding approach and smart contract knowledge.
CTO interview - A final discussion to evaluate technical reasoning, architectural thinking, and team fit. Successful candidates may receive an offer through Contra following this conversation.
Payment in Crypto
Rui Silva
Senior Blockchain Developer - Ethereum/PulseChain - GAM3S.GG
Lisbon, Portugal
Lisbon, Portugal
Full time
Remote
About the Job
We're looking for a Senior Blockchain Developer with strong Ethereum/PulseChain smart contract experience to work on our DeFi/GameFi platform. You'll be building and maintaining betting contracts, yield farming mechanisms, token swap systems, and Web3 frontend integrations for our decentralized application on PulseChain.
Key Responsibilities
Smart Contract Development
System Architecture & Integration
Frontend Web3 Integration
Security & Compliance
Performance & Monitoring
Required Technical Skills
Blockchain Expertise
Frontend Web3 Development
Development Tools
Integration & Tools
We're looking for a Senior Blockchain Developer with strong Ethereum/PulseChain smart contract experience to work on our DeFi/GameFi platform. You'll be building and maintaining betting contracts, yield farming mechanisms, token swap systems, and Web3 frontend integrations for our decentralized application on PulseChain.
Key Responsibilities
Smart Contract Development
System Architecture & Integration
Frontend Web3 Integration
Security & Compliance
Performance & Monitoring
Required Technical Skills
Blockchain Expertise
Frontend Web3 Development
Development Tools
Integration & Tools
Payment in Crypto
Tatyana Khrustaleva
Senior Go Developer
Full time
Remote
Senior Go Developer (Crypto focus; remote) The company (name withheld till the interview stage) is a non-custodial staking, re-staking, and node hosting platform that delivers advanced, secure infrastructure for institutional and retail investors. With automated services and an intuitive interface, we simplify the process of running full nodes, masternodes, and validators across 77 Proof-of-Stake blockchain protocols, hosting tens of thousands of nodes globally.In addition, we contribute to the blockchain ecosystem by offering complimentary tools and RPC endpoints for over 100 blockchain protocols, enabling users and developers to engage with their preferred blockchain networks and build innovative solutions!We are seeking a strong Senior Go Developer with experience in cryptocurrency. Requirements:Cryptocurrency and Node Experience: Minimum 1.5–2 years of experience working in the cryptocurrency space, specifically with nodes.Extensive experience and expertise in Go development.Russian or Ukrainian language proficiency.Knowledge of Node.js is a plus.Experience working in a remote, asynchronous environment.Familiarity with Slack for communication and collaboration.Working hours:You may start your 8-hour working day between 7 and 11 am GMT+3. For example, from 9 am to 5 pm GMT+3, etc.Remote team spanning from Los Angeles to London to Dubai, with minimal calls and Slack-based communication & decision-making.The team consists of 6-10 members with a strong sense of commitment—many have been with us for over 7 years. What we offer:Full-time job (8 working hours per day, Monday-Friday).Remote work. You may be located in any country, just need a good Internet connection, a powerful computer to work from, and the opportunity to adjust your working schedule for the team.Be part of a fast-growing, highly respected company in the crypto industry.Stability. This is not project work, we consider only the candidates looking for a long-term commitment of 1.5+ years.Work autonomously with a team of like-minded professionals.Engage in challenging and innovative projects with cutting-edge blockchain technologies.Salary will be discussed during the interview. Paid in USDT. Application deadline: ASAPSelection process:1. Fill in the application form - attach your CV & a GitHub portfolio link;2. Have a Zoom interview with Hire5 Recruiter;3. Have a technical Zoom meeting with the developer from the company team;4. Have a quick Zoom interview with the CEO of the company;5. Get hired!
Payment in Crypto
Hazel Thomas
Web3 + Supabase Developer Needed to Complete BSC Testnet Waitlist & Staking Platform
Washington, USA
Washington, USA
Part time
Remote
📌 Job Description
We are building a production-ready Web3 waitlist and dashboard platform using Next.js 15 (App Router), BSC Testnet, Supabase, and Wagmi v2.
The core architecture, database schema, and feature roadmap are already defined. We are looking for an experienced developer to complete, polish, and harden the project.
This is not a prototype — the goal is a fully working, deployable system with clean code, security best practices, and proper Web3 UX.
🧩 Project Overview
The platform includes:
Wallet-based user registration (BSC Testnet only)
Automatic network detection & switching
Supabase-backed user management
Automatic virtual card generation (Bronze / Silver / Gold)
Token staking system with transaction logging
Referral system with rewards tracking
Dashboard with analytics & history
X (Twitter) OAuth integration
Discord bot with XP & invite tracking
A detailed README and database schema are already prepared.
✅ Responsibilities
You will be responsible for:
Completing and stabilizing the Next.js App Router implementation
Finalizing wallet connection & network enforcement (Chain ID 97)
Ensuring Supabase RLS policies are correct and secure
Implementing or completing:
Staking flows (stake, unstake, claim, emergency withdraw)
Referral tracking & reward logic
Dashboard analytics & transaction history
Finalizing X (Twitter) OAuth integration
Reviewing and improving overall code quality & structure
Fixing bugs, edge cases, and UX issues
Preparing the app for Railway deployment
(Bonus) Improving performance and Web3 UX
🛠 Tech Stack (Must-Have Experience)
Required:
Next.js 14/15 (App Router)
TypeScript
Wagmi v2 + WalletConnect
EVM chains (BSC preferred)
Supabase (Postgres, RLS, triggers, SQL functions)
Tailwind CSS
Web3 transaction handling & logging
Nice to Have:
Discord bot development (Node.js)
OAuth 2.0 (X / Twitter)
Smart contract interaction (staking contracts)
Framer Motion
shadcn/ui / Radix UI
🔒 Security Expectations
You must be comfortable with:
Wallet validation & chain enforcement
Preventing self-referrals & abuse
Transaction hash uniqueness checks
Secure handling of OAuth tokens
Supabase RLS & role-based access
📦 Deliverables
Fully working, deployable application
Clean, documented codebase
Verified Supabase schema & policies
Functional staking & referral systems
Deployment-ready build (Railway)
Basic handover documentation
⏳ Timeline
Estimated duration: 2–4 months
Start: Immediately
Potential for long-term collaboration
💰 Budget
Open to fixed-price or hourly
Please include:
Your estimated timeline
Relevant Web3 / Next.js projects
Any questions or suggestions to improve the system
🧠 How to Apply
When applying, please answer:
Have you built production Web3 apps with Next.js + Wagmi before?
Have you worked with Supabase RLS & SQL triggers?
Share 1–3 relevant projects (GitHub or live links)
What risks or improvements do you see in this architecture?
Generic proposals will be ignored.
We are building a production-ready Web3 waitlist and dashboard platform using Next.js 15 (App Router), BSC Testnet, Supabase, and Wagmi v2.
The core architecture, database schema, and feature roadmap are already defined. We are looking for an experienced developer to complete, polish, and harden the project.
This is not a prototype — the goal is a fully working, deployable system with clean code, security best practices, and proper Web3 UX.
🧩 Project Overview
The platform includes:
Wallet-based user registration (BSC Testnet only)
Automatic network detection & switching
Supabase-backed user management
Automatic virtual card generation (Bronze / Silver / Gold)
Token staking system with transaction logging
Referral system with rewards tracking
Dashboard with analytics & history
X (Twitter) OAuth integration
Discord bot with XP & invite tracking
A detailed README and database schema are already prepared.
✅ Responsibilities
You will be responsible for:
Completing and stabilizing the Next.js App Router implementation
Finalizing wallet connection & network enforcement (Chain ID 97)
Ensuring Supabase RLS policies are correct and secure
Implementing or completing:
Staking flows (stake, unstake, claim, emergency withdraw)
Referral tracking & reward logic
Dashboard analytics & transaction history
Finalizing X (Twitter) OAuth integration
Reviewing and improving overall code quality & structure
Fixing bugs, edge cases, and UX issues
Preparing the app for Railway deployment
(Bonus) Improving performance and Web3 UX
🛠 Tech Stack (Must-Have Experience)
Required:
Next.js 14/15 (App Router)
TypeScript
Wagmi v2 + WalletConnect
EVM chains (BSC preferred)
Supabase (Postgres, RLS, triggers, SQL functions)
Tailwind CSS
Web3 transaction handling & logging
Nice to Have:
Discord bot development (Node.js)
OAuth 2.0 (X / Twitter)
Smart contract interaction (staking contracts)
Framer Motion
shadcn/ui / Radix UI
🔒 Security Expectations
You must be comfortable with:
Wallet validation & chain enforcement
Preventing self-referrals & abuse
Transaction hash uniqueness checks
Secure handling of OAuth tokens
Supabase RLS & role-based access
📦 Deliverables
Fully working, deployable application
Clean, documented codebase
Verified Supabase schema & policies
Functional staking & referral systems
Deployment-ready build (Railway)
Basic handover documentation
⏳ Timeline
Estimated duration: 2–4 months
Start: Immediately
Potential for long-term collaboration
💰 Budget
Open to fixed-price or hourly
Please include:
Your estimated timeline
Relevant Web3 / Next.js projects
Any questions or suggestions to improve the system
🧠 How to Apply
When applying, please answer:
Have you built production Web3 apps with Next.js + Wagmi before?
Have you worked with Supabase RLS & SQL triggers?
Share 1–3 relevant projects (GitHub or live links)
What risks or improvements do you see in this architecture?
Generic proposals will be ignored.
Payment in Crypto
lucas martin
Senior Web3 / Crypto Trading Platform Developer
Full time
Remote
PumaPulse is launching a new standalone domain focused on building professional-grade crypto trading platforms and on-chain trading tools. We are seeking an experienced freelance Web3 developer to help design, build, and evolve a scalable trading product with commercialization potential.ResponsibilitiesDevelop crypto trading tools, bots, or SaaS platformsIntegrate with DEXs and on-chain protocols (e.g., Solana, Ethereum)Implement real-time blockchain data monitoring and trade executionEnsure security, performance, and MEV-aware designCollaborate on product roadmap, strategy, and future featuresRequirementsStrong experience in Web3 and DeFi developmentProven work with crypto trading bots or on-chain trading systemsExperience with at least one major blockchain ecosystemSolid understanding of smart contract interaction and security best practicesAbility to deliver production-ready code and communicate clearlyNice to HaveExperience productizing tools into SaaS platformsBackground in advanced trading strategies or MEVPrior work with VC-backed or early-stage Web3 projectsEngagementFreelance / contract roleCompetitive compensation based on experiencePotential for long-term collaborationApply with relevant Web3 projects, GitHub links, and availability.
Payment in Crypto