Principal/Senior Engineer - Blockchain Development Engineer
Hong Kong
Full time
Office
Compensation is not specified
Role
Software Engineer
Description
About the Company
At OKX, we are shaping the future with advanced technology. Established in 2017, OKX stands out as a prominent cryptocurrency exchange for spot and derivatives trading. Utilizing blockchain technology, OKX offers a wide range of innovative products and solutions that are transforming the financial landscape. Trusted by over 20 million users across 180 regions globally, OKX aims to provide a dynamic platform for individuals to delve into the realm of crypto. Alongside the top-notch DeFi exchange, OKX is also known for OKX Insights, a research arm that stays abreast of industry trends. With a diverse array of crypto services and a focus on innovation, OKX envisions a world where financial accessibility is empowered by blockchain technology and decentralized finance.
We value our team just as much as we value technology. We foster a collaborative culture where success is shared, change is embraced, and integrity is paramount. Our mission is to cultivate a welcoming, enriching, and inclusive environment for all team members, regardless of their background, where everyone is appreciated, respected, and offered equal opportunities for growth and success.
Opportunity Overview
- Engage with top talents in blockchain technology, contributing to the development and enhancement of security tools, and remaining at the forefront of this rapidly changing industry.
- Access continuous learning opportunities to enhance skills, including hands-on experience in smart contract auditing and security tools development.
- Make a global impact through the utilization of our widely-used Web3 products, and contribute to their safety and reliability.
Responsibilities
- Direct the design, development, thorough testing, and optimization of performance for L1 or L2 blockchain projects.
- Lead communication efforts and actively contribute to well-known blockchain projects like Ethereum, Polygon, and others in mainstream usage.
- Drive the development of ZKEvm and related components.
- Collaborate with the team to create scalable blockchain solutions.
- Engage in product planning and devise technical roadmaps.
- Address development challenges, conduct fault diagnosis, and implement fixes.
Qualifications
- Bachelor's degree in Computer Science, Software Engineering, or a related field, or equivalent practical experience.
- Preferably possess 2-3 years of experience in blockchain development, with proficiency in Golang, Rust, C++, or related languages.
- Solid comprehension of blockchain technology, including Ethereum, Polygon, Bitcoin, Solana, and L2 networks.
- Exposure to zero-knowledge proof development, particularly zkvm, and familiarity with principles of plonk/halo2/KZG/FRI, along with related libraries or circuit development languages such as plonky2, Circum, gnark.
- Familiarity with performance optimization tools like Gperftools, Profiler, Flamegraph, Pprof, etc., and experience in performance optimization development within projects. Knowledge of zk GPU acceleration is beneficial.
- Excellent analytical skills, problem-solving capabilities, and team collaboration aptitude.
Desirable Qualifications
- Profound understanding of the workings of mainstream ZK-Rollup L2 technology and in-depth awareness of ZKEvm technicalities.
- Hands-on experience in L2 blockchain projects like polygon\linea\zksync.
- Proficiency in ZKP like groth16, fflonk, plonky2.
Benefits
- Competitive total compensation package.
- Extensive insurance coverage for employees and their dependents.
- Further perks and benefits to be elaborated on during the selection process.
Skills Required
OKX
Website
www.okx.comCompany size
Not specified
Location
United States
Description
Not specified
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