Senior Back-End Engineer, DeFi Wallet
Paris, France
Full time
Office
Compensation is not specified
Role
Backend Engineer
Description
DESCRIPTION
Blockchain.com is the forefront software platform for digital assets globally. We are seeking Kotlin and Solidity Developers with expertise in blockchain protocols and EVM networks. As a backend engineer on the DeFi team, you will be involved in a variety of projects, such as enhancing our non-custodial wallets network support and developing smart contracts. Additionally, you will be tasked with integrating third-party vendors supplying data for crypto tokens, DApps, and DAOs and centralizing logic from wallet clients into backend services.
In the role of a Senior Back-End Engineer, your responsibilities include leading technical discussions, influencing the approach, and advocating for best engineering practices to positively impact the team's development.
RESPONSIBILITIES
- Develop robust, reliable software to manage multiple networks and support our expanding range of products and users
- Collaborate with an engineering team dedicated to maintaining high standards and deploying secure and high-performing systems
- Engage directly with multiple blockchains in the core of Blockchain.com's solution
- Utilize open source technologies like Docker, Kafka, and MySQL
- Prioritize security in all aspects of the work
- Collaborate with interdisciplinary teams to consistently deliver high-quality products
- Optimize existing systems for scalability, extensibility, and performance while creating reusable, modular code for various Blockchain.com products
REQUIREMENTS
- Integrity, the most essential quality for this role
- Proficiency in Typescript, Solidity, and ideally Kotlin/JVM
- Experience with Blockchain technologies, particularly EVM or non-EVM chains and defi protocols
- Strong motivation, self-driven, and enthusiastic about cryptocurrencies
- Comprehensive understanding of blockchain systems and ideally prior experience working closely with one
- Ability to navigate novel challenges and curiosity to learn new technologies
- Advocacy for best engineering practices, proficiency in multiple programming languages, and a practical approach to solving complex problems
- Commitment to high levels of test coverage, technical documentation, and effective monitoring
- Accountability for all assigned projects
COMPENSATION & BENEFITS
- Competitive salary based on experience and equity in a leading company
- Prime office location in Paris with mandatory on-site work for four days per week
- Work from Anywhere policy
- Opportunity to play a significant role and progress in a rapidly expanding technology company within an emerging industry
- Unlimited vacation policy, inclusive of performance-based bonuses paid in cash
- Company-issued Apple equipment
Skills Required
Blockchain.com
Website
www.blockchain.comCompany size
Not specified
Location
United States
Description
Not specified
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
Astralis Capital
Personal Assistant to Managing Partner
London, UK
London, UK
Full time
Remote
The Context
Kieran McLoughlin has navigated the highest levels of traditional finance as the former Head of the Central Bank of Ireland. Today, as Managing Partner at Astralis, he is at the frontier of Web3 investment. We are looking for a unique individual to bridge these two worlds: someone who understands the rigor of institutional finance but lives and breathes the decentralized future.
This isn't a traditional "admin" role. This is a high-bandwidth, high-stakes position for a Web3 native who can act as a technical filter, a marketing scout, and a strategic executor.
The Mission
Technical Intelligence: You are the "eyes" on-chain. You’ll be responsible for vetting protocols, testing dApps, and analyzing tokenomics. You should be able to break down a complex ZK-rollup or liquid staking architecture into a concise briefing.
Marketing & Alpha Hunting: You live on X (Twitter), Farcaster, and in closed Discord research groups. You identify emerging meta-narratives before they hit the mainstream. You understand why a community thrives and how a project builds its "moat" through marketing.
Strategic Operations: Managing the flow of a Managing Partner’s world. This includes coordinating with founders of top-tier Web3 projects, preparing materials for the Investment Committee, and ensuring Kieran’s digital and technical stack is always optimized.
Executive Presence: You will represent the office of the Managing Partner. You must be able to switch from degen-speak in a Telegram chat to professional discourse with institutional LPs.
The Profile (Who You Are)
On-Chain Native: You have a DeBank profile that tells a story. You’ve bridged, swapped, provided liquidity, and perhaps been "rugged" once or twice. You don’t just read about crypto; you use it daily.
Technical Literacy: You understand the difference between consensus layers and execution layers. You can read a smart contract (at least the basics) and understand the implications of governance proposals.
Marketing Intuition: You know what "good" looks like in Web3. You can distinguish between organic community growth and paid bot engagement.
Hyper-Organized: You are a master of calendars, task management, and information flow. You thrive in high-pressure environments where speed and accuracy are non-negotiable.
Discretion & Integrity: Working with an ex-regulator requires the highest level of ethics and confidentiality.
Why This Role?
Direct Mentorship: Work side-by-side with Kieran McLaughlin. This is a masterclass in macroeconomics, regulatory strategy, and venture capital.
Access: You will be in the room for the deals that will define the next cycle of Web3.
Impact: Your technical and marketing insights will directly inform the Investment Committee’s decisions.
How to Apply:
Standard CVs are fine, but we care more about your "proof of work." Along with your resume, send us:
A brief summary of your most interesting on-chain move or investment thesis.
Your X (Twitter) handle or your DeBank/Nansen profile link.
Skills
Analytical Thinking
Communications Skills
Crypto Revenue Management
Cryptocurrency
Tokenomics
Kieran McLoughlin has navigated the highest levels of traditional finance as the former Head of the Central Bank of Ireland. Today, as Managing Partner at Astralis, he is at the frontier of Web3 investment. We are looking for a unique individual to bridge these two worlds: someone who understands the rigor of institutional finance but lives and breathes the decentralized future.
This isn't a traditional "admin" role. This is a high-bandwidth, high-stakes position for a Web3 native who can act as a technical filter, a marketing scout, and a strategic executor.
The Mission
Technical Intelligence: You are the "eyes" on-chain. You’ll be responsible for vetting protocols, testing dApps, and analyzing tokenomics. You should be able to break down a complex ZK-rollup or liquid staking architecture into a concise briefing.
Marketing & Alpha Hunting: You live on X (Twitter), Farcaster, and in closed Discord research groups. You identify emerging meta-narratives before they hit the mainstream. You understand why a community thrives and how a project builds its "moat" through marketing.
Strategic Operations: Managing the flow of a Managing Partner’s world. This includes coordinating with founders of top-tier Web3 projects, preparing materials for the Investment Committee, and ensuring Kieran’s digital and technical stack is always optimized.
Executive Presence: You will represent the office of the Managing Partner. You must be able to switch from degen-speak in a Telegram chat to professional discourse with institutional LPs.
The Profile (Who You Are)
On-Chain Native: You have a DeBank profile that tells a story. You’ve bridged, swapped, provided liquidity, and perhaps been "rugged" once or twice. You don’t just read about crypto; you use it daily.
Technical Literacy: You understand the difference between consensus layers and execution layers. You can read a smart contract (at least the basics) and understand the implications of governance proposals.
Marketing Intuition: You know what "good" looks like in Web3. You can distinguish between organic community growth and paid bot engagement.
Hyper-Organized: You are a master of calendars, task management, and information flow. You thrive in high-pressure environments where speed and accuracy are non-negotiable.
Discretion & Integrity: Working with an ex-regulator requires the highest level of ethics and confidentiality.
Why This Role?
Direct Mentorship: Work side-by-side with Kieran McLaughlin. This is a masterclass in macroeconomics, regulatory strategy, and venture capital.
Access: You will be in the room for the deals that will define the next cycle of Web3.
Impact: Your technical and marketing insights will directly inform the Investment Committee’s decisions.
How to Apply:
Standard CVs are fine, but we care more about your "proof of work." Along with your resume, send us:
A brief summary of your most interesting on-chain move or investment thesis.
Your X (Twitter) handle or your DeBank/Nansen profile link.
Skills
Analytical Thinking
Communications Skills
Crypto Revenue Management
Cryptocurrency
Tokenomics
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
Austin Smart
Fullstack Developer Needed for Web3 Prediction Market Platform
Brooklyn, USA
Brooklyn, USA
Full time
Remote
Summary
We're looking for an experienced Blockchain / Full-Stack Developer to help build a production-ready MVP for a Web3 prediction marketplace.
We’ve already built a basic UI prototype using vibe coding. The goal now is to turn this prototype into a functional, scalable dApp with clean architecture and solid Web3 fundamentals.
This is not a tutorial or experimental project — We’re looking for someone who has real experience shipping blockchain/web3 products.
What You’ll Do
Review and improve an existing UI prototype
Build smart contract logic for a prediction marketplace MVP
Integrate blockchain functionality with the frontend
Develop backend / API logic as needed
Ensure clean, maintainable, production-ready code
Collaborate on product decisions and MVP scope
Tech Stack (Preferred)
Frontend: Next.js / React
Backend: Node.js
Blockchain: Solidity / Rust
Experience with non-EVM chains is a plus (open to discussion)
What We're Looking For
- Strong experience in Blockchain & Web3 development
- Proven ability to build production-ready dApps
- Proficiency in Next.js, React, and Node.js
- Experience designing and shipping MVPs
- Good communication and ability to work independently
Nice to Have
- Previous work on prediction markets, DeFi, or marketplaces
- Experience taking projects from prototype to launch
- Performance, security, and scalability mindset
How to Apply
Please include:
- A brief summary of your Web3 experience
- Links to previous dApps or blockchain projects
- Your preferred tech stack and availability
If you’re an expert in blockchain and Web3 and enjoy building real products from early prototypes, We’d love to hear from you.
We're looking for an experienced Blockchain / Full-Stack Developer to help build a production-ready MVP for a Web3 prediction marketplace.
We’ve already built a basic UI prototype using vibe coding. The goal now is to turn this prototype into a functional, scalable dApp with clean architecture and solid Web3 fundamentals.
This is not a tutorial or experimental project — We’re looking for someone who has real experience shipping blockchain/web3 products.
What You’ll Do
Review and improve an existing UI prototype
Build smart contract logic for a prediction marketplace MVP
Integrate blockchain functionality with the frontend
Develop backend / API logic as needed
Ensure clean, maintainable, production-ready code
Collaborate on product decisions and MVP scope
Tech Stack (Preferred)
Frontend: Next.js / React
Backend: Node.js
Blockchain: Solidity / Rust
Experience with non-EVM chains is a plus (open to discussion)
What We're Looking For
- Strong experience in Blockchain & Web3 development
- Proven ability to build production-ready dApps
- Proficiency in Next.js, React, and Node.js
- Experience designing and shipping MVPs
- Good communication and ability to work independently
Nice to Have
- Previous work on prediction markets, DeFi, or marketplaces
- Experience taking projects from prototype to launch
- Performance, security, and scalability mindset
How to Apply
Please include:
- A brief summary of your Web3 experience
- Links to previous dApps or blockchain projects
- Your preferred tech stack and availability
If you’re an expert in blockchain and Web3 and enjoy building real products from early prototypes, We’d love to hear from you.
Payment in Crypto
Emir Hammami
Looking for a blockchain developer
Whiteman Air Force Base, USA
Whiteman Air Force Base, USA
Full time
Remote
We are looking for a skilled Full-Stack Blockchain Developer to help maintain, improve, and extend the RaiseHive platform. This role involves working across the frontend, backend, and smart contract layers to ensure a stable, secure, and scalable Web3 application.
The ideal candidate has hands-on experience with React, Node.js, Ethereum smart contracts, and real-world Web3 integrations.
Framework: React 18.2 (Vite 3)
Styling: Tailwind CSS 3.4, NextUI
Animations: Framer Motion
Web3: Thirdweb SDK v4, Ethers.js v5
Routing: React Router DOM v6
State Management: React Context API
Libraries: React Markdown, React Image Gallery, Replyke (comments), React Toastify
Runtime: Node.js
Framework: Express.js
Database: MongoDB Atlas (Mongoose ODM)
Email: Nodemailer
Scheduling: Node-cron
Logging: Pino
Network: Ethereum
Smart Contracts: Solidity ^0.8.19
Development Tools: Hardhat
Libraries: OpenZeppelin, Thirdweb Contracts
Wallet Integration: MetaMask
Frontend
Strong proficiency in React (hooks, context, routing)
Experience with Vite or modern build tools
Solid knowledge of Tailwind CSS and responsive design
Experience using component libraries (NextUI, Material UI, etc.)
Backend
Strong experience with Node.js and Express
Proficiency with MongoDB and Mongoose
REST API design and implementation
Environment configuration and deployment awareness
Blockchain & Web3
Hands-on Ethereum development experience
Solidity smart contract development
Experience with Ethers.js / Thirdweb SDK
Understanding of smart contract security and gas optimization
MetaMask wallet integration and transaction handling
General
JavaScript (ES6+)
Git version control
Async programming and debugging skills
Strong problem-solving ability
The ideal candidate has hands-on experience with React, Node.js, Ethereum smart contracts, and real-world Web3 integrations.
Framework: React 18.2 (Vite 3)
Styling: Tailwind CSS 3.4, NextUI
Animations: Framer Motion
Web3: Thirdweb SDK v4, Ethers.js v5
Routing: React Router DOM v6
State Management: React Context API
Libraries: React Markdown, React Image Gallery, Replyke (comments), React Toastify
Runtime: Node.js
Framework: Express.js
Database: MongoDB Atlas (Mongoose ODM)
Email: Nodemailer
Scheduling: Node-cron
Logging: Pino
Network: Ethereum
Smart Contracts: Solidity ^0.8.19
Development Tools: Hardhat
Libraries: OpenZeppelin, Thirdweb Contracts
Wallet Integration: MetaMask
Frontend
Strong proficiency in React (hooks, context, routing)
Experience with Vite or modern build tools
Solid knowledge of Tailwind CSS and responsive design
Experience using component libraries (NextUI, Material UI, etc.)
Backend
Strong experience with Node.js and Express
Proficiency with MongoDB and Mongoose
REST API design and implementation
Environment configuration and deployment awareness
Blockchain & Web3
Hands-on Ethereum development experience
Solidity smart contract development
Experience with Ethers.js / Thirdweb SDK
Understanding of smart contract security and gas optimization
MetaMask wallet integration and transaction handling
General
JavaScript (ES6+)
Git version control
Async programming and debugging skills
Strong problem-solving ability
Payment in Crypto