Hire Vetted Blockchain Engineers at Upstaff

All vetted software engineers you need to build AI, Web3, and data Products.
  • Dedicated Full-time commitment for long-term or Time& Material for shorter or ongoing support
  • Europe, Israel, LatAm, United States, Asia geography coverage
  • Remote and hybrid engagement
  • Trial period, no termination fees or hidden costs for transparent and risk-free onboarding.
JavaScript 8yr.
React 8yr.
TypeScript 5yr.
Node.js 5yr.
AWS
...
  • 10+ years of experience in web development, M.Sc in Software Engineering, GAI, LLMs.
  • Back-End: Node.js, Next.js, TypeScript , PHP, Java (Basics).
  • Front-End: JavaScript & TypeScript (React, Angular, Vue.js).
  • Mobile: React Native.
  • AWS Cloud infrastructure, Lambda/Serverless, SNS/SQS Queues.
  • Control systems (e.g., Git) and familiarity with DevOps practices for continuous integration and deployment (CI/CD).
  • Unit testing, integration testing, and end-to-end testing.
  • Experience leading and mentoring a team of developers, including assigning tasks, providing guidance, and ensuring the team's success. Conducting assessments and interviews remotely. Ability to motivate and inspire team members, resolve conflicts, and provide constructive feedback.
Show more
Seniority Architect/Team-lead
Location Ukraine
Haskell 3yr.
Scala 2yr.
Plutus 2yr.
Akka
Cardano
...
- 3 years of experience in Plutus / Cardano smart contracts developer role (Plutus Core, Plutarch) - Cardano ecosystem knowledge - Haskell, Scala, Cabal/Stack, GADTs/Type families, Generics, Servant, lenses, mtl, free monads - senior-level professional - Functional programming with FRP, Redux, Event sourcing, Category theory - OOP, OOD, UML, Design patterns, SOLID, DI. TDD, BDD, Unit, functional, and integration testing - 14 years of experience in software engineering
Show more
Node.js 5yr.
React 3yr.
Solidity
NFT
...
• 15+ years of commercial software development experience • Solid knowledge of Solidity, C++, JavaScript, TypeScript; • Deep understanding of blockchain architecture and smart contract logic; • Cosmos, Tron, Avalanche, Binance Smart Chain, Ethereum dApps; • Strong skills in developing NFT smart contracts. Support and payload verification; • NFT Marketplaces (ERC - 721/1155), Crypto Payment Solutions & DeFi Cross Chain Bridges - ERC-20 Tokens, ICO, DEX, Staking, Swapping; • Highly qualified knowledge of Stripe payment system integration to blockchain data; • 10+ years experience working with Python; • 5 years experience working with Node.js; • Strong abilities with Express; • Experience working with Docker, and Kubernetes (K8s); • 3+ years of development experience with React.js. • No scheduled vacations within the next 3 months;
Show more
Seniority Senior
Location Ukraine
Python 5yr.
Django 3yr.
Mobile development
Flask
API
...
  • Python Developer with 6+ years of experience in backend development and automation: Django (4 years), Flask, and Fast API for web application development;
  • Built and supported Telegram bots and automation tools for business operations (dApp Marketplaces, Crypto ATMs, Payments and Casino games)
  • Maintaining and supporting production systems using FastAPI and SQLAlchemy, API integrations including financial services and crypto platforms;
  • Docker containerization: Docker-compose, Docker via Render (serverless). Deployment and Linux server management (Ubuntu);
  • Familiar with data reporting and basic analytics through internal monitoring tools; - Open to part-time and distributed team environments with a focus on ongoing system support.
  • Reached the Top 10 freelance Python engineers on the local market at the age of 17 (showcasing early talent and initiative).
  • Worked on projects with a multi-million user base, contributing to scalable architecture and high-load system stability.
  • Successfully launched an educational platform in the USA, now actively used by students, tutors, and academic institutions.
  • Represented the dev team at the international Wefi Beyond Banking Summit, delivering a product presentation to a global fintech audience.
Show more
Seniority Middle
Location Ternopil, Ukraine
JavaScript 9yr.
React 8yr.
TypeScript
...
  • Front-end JavaScript Engineer with 9 years of commercial experience;
  • 8+ years of hands-on experience with React, and TypeScript, including complex component architectures, shared UI libraries, and micro-frontend approaches using Module Federation;
  • Experience with automated testing, covering unit, integration, and end-to-end tests using Jest, React Testing Library, Cypress, and Playwright;
  • Experience with Next.js, focusing on performance optimization, scalability, and modular application design;
  • Expertise in Web3 and blockchain integrations, including crypto wallets, on-chain data, and decentralized authentication;
  • Background in FinTech and crypto products, delivering secure, user-facing interfaces for wallets, cards, and transaction flows;
  • Experience working and leading within distributed Agile teams, collaborating closely with backend, security, and product stakeholders.

Show more
Seniority Senior
Location Castel San Giovanni, Italy
Rust
Solana
...
- Senior Blockchain Engineer with 20+ years in software development and a strong track record in the Solana ecosystem; - Experienced in Rust for Solana smart contract development, with extensive experience building on-chain programs for DeFi, staking, NFT, and messaging platforms; - Skilled in full-stack development: React and TypeScript for front-end dApps, Node.js and Python for backend systems; - Experience with AWS and Google Cloud for scalable cloud applications and infrastructure; - Ability to lead teams and manage projects, including migrating Ethereum products to Solana (Community Gaming); - Skilled in blockchain frameworks and tools: Anchor, CPI, Metaplex, Token-2022; - Strong SQL background with hands-on experience in PostgreSQL, MySQL, and SQLite; - Experienced in system architecture, Linux server administration, and distributed applications; - Notable achievements include leading Solana product delivery for NeuralBond (on-chain messaging) and Palus Finance (staking platform).
Show more
Python
Django
Flask
...
- 5 years of experience in the IT industry as a Python Engineer - Proficient in using technologies such as Django DRF, Flask, Pandas, BeautifulSoup, SQLAlchemy, Asyncio, Flask + Marshmallow, Apscheduler, Jinja, Quip API, Docker, Nginx, Amazon MWS API, Amazon SP-API, Google API, and Telegram API; - Strong in refactoring, bug-fixing, and working with Python, JavaScript, Django, Django Rest Framework; - Skilled in developing faceted search and matching algorithms using ElasticSearch; - Experienced in PDF generation and importing from various formats; - Developed web applications, API interfaces, and automated scripts for data transformation; - Previous experience includes working as a Python developer focused on data scraping for Amazon, eBay, and Walmart products in dropshipping projects; - Also worked as a C# developer on various projects, specializing in web development, scraping, and parsing data; - Upper-Intermediate English; - Available ASAP
Show more
Seniority Senior
Location United States
Node.js 5yr.
NestJS 4yr.
React 3yr.
Ext JS 3yr.
Go 2yr.
...
  • Full-Stack Developer with 5+ years of experience specializing in React, Next.js, Nest.js, and Golang for scalable web and crypto-rewards platforms.
  • Proven expertise in building high-performance GraphQL APIs, optimizing backend systems, and integrating Web3 wallets and AWS S3 for secure data management.
  • Skilled in Agile methodologies, CI/CD automation using GitHub Actions and Azure, enhancing deployment speed by up to 40%.

Show more
React 2yr.
Node.js 2yr.
PostgreSQL 2yr.
...
  • Blockchain integration across EVM and Solana networks, including real-time token swaps, wallet management, and secure transaction processing.
  • Proficient in designing optimized PostgreSQL schemas and implementing microservices with asynchronous processing for high-throughput financial systems.
  • Master’s degree in Computer Science underpinning solid engineering principles, API design, and agile delivery within cross-functional international teams.

Show more
Rust
C/C++/C#
Python
TypeScript
Solidity
...
  • Expertise in zero-knowledge proof systems including ZK-SNARK, Plonk, Groth16, and zkVM optimization for Layer 2 privacy solutions.
  • Proficient in Rust blockchain development, designing high-performance node components, consensus algorithms, and secure cryptographic primitives.
  • Skilled in cloud-native infrastructure automation using Kubernetes, Terraform, CI/CD, and observability with Prometheus and Grafana ensuring 99.9% uptime.
  • Hands-on experience with decentralized network protocols, peer-to-peer systems using libp2p, and distributed storage architectures.
  • Strong quantitative finance background with MSc in progress, combining advanced cryptography, blockchain protocols, and privacy computing expertise.
Show more
JavaScript 2yr.
TypeScript 2yr.
React 2yr.
Node.js 2yr.
...
  • Senior Software Engineer with 10+ years of expertise in scalable web applications and distributed systems using JavaScript, TypeScript, React.js, Node.js, and Python.
  • Proven leadership in transitioning to event-sourcing architectures, achieving 39× faster read query performance and enhancing system scalability.
  • Extensive experience in microservices, REST API development, and database optimization with MongoDB and PostgreSQL for high-performance applications.
  • Skilled in integrating AI-powered development tools like Claude Code and Cursor IDE to boost engineering productivity and innovation.
  • Strong background in full software development lifecycle, team mentoring, and delivering complex solutions across diverse domains including industrial monitoring, telecommunication, and asset trading.
Show more
Seniority Senior
Location Ukraine
React 5yr.
TypeScript 5yr.
Ext JS 3yr.
...
  • Senior Frontend Engineer with 6+ years of expertise in React.js, Next.js, TypeScript, and modern frontend architectures, delivering high-performance trading interfaces and blockchain-enabled applications.
  • Proficient in state management (Redux Toolkit, MobX), UI frameworks (Tailwind CSS, Material UI), and Web3 integrations including wallet connections and smart contract interactions.
  • Led development of scalable crypto exchange platforms with real-time data processing, multi-currency wallet management, and KYC/AML compliance workflows.
  • Experienced in Agile methodologies, CI/CD pipelines, and test-driven development using Jest, React Testing Library, and Cypress to ensure robust, maintainable codebases.
  • Holds a Bachelor's degree in Information Technologies, with strong skills in backend (Node.js, NestJS), databases (MongoDB, PostgreSQL), and cloud DevOps (Docker, AWS, Azure).
Show more
Node.js 4yr.
TypeScript 3yr.
MondoDB 3yr.
DI 2yr.
...
  • Proficient in TypeScript and Node.js with hands-on experience in building scalable backend systems and real-time integrations using Bun runtime.
  • Developed a multi-account Discord-to-Telegram message bridge featuring modular dependency injection, GPT-4o-mini translation, advanced content filtering, and robust proxy/captcha handling with MongoDB persistence.
  • Skilled in Telegram bot development using Telegraf and node-canvas, implementing multiplayer game logic and dynamic graphical rendering.
  • Experienced with REST APIs, WebSockets, OpenAI API integrations, and complex asynchronous workflows emphasizing clean, maintainable code architecture.
  • Self-taught with a strong focus on practical software engineering principles, modular design patterns, and delivering client-ready solutions under tight deadlines.
Show more
Seniority Junior
Location Russia
Flutter 4yr.
GCP 4yr.
Firebase 4yr.
Go
...
* Software engineer with over 4 years of experience in mobile app development, specializing in Flutter and proficient in Dart, Kotlin, and Go. * Strong technical expertise in building robust backend systems, REST APIs, and has a keen interest in Blockchain technology within the GCP ecosystem. * Demonstrated ability in web development using modern technologies including HTML, CSS, JavaScript, React, and NextJs. * Active contributor to open-source projects, enhancing the value of platforms like APIDash and GoCoin. * Holds a Bachelor's and a Master's degree in Computer Engineering, underpinning a solid understanding of software development practices. * Recognized for building impactful mobile applications such as Edutive for education and Racha for addiction management.
Show more
Seniority Middle
Location Bamenda, Cameroon
Python 7yr.
Solidity 6yr.
Solana 4yr.
JavaScript 3yr.
Rust 2yr.
...
- Team Lead / Tech Lead / Software Engineer / Blockchain Developer with 10 years of experience. - Strong expertise in blockchain development, building decentralized applications (dApps) using Solidity and Rust for EVM and Solana networks. - Proficient in frameworks like HardHat and Anchor. - Develop, test, and deploy smart contracts, integrating wallets (e.g., Metamask) and working with DeFi protocols (Uniswap, Aave) and NFT standards (ERC-20, ERC-721). - Has solid experience in backend development using Django, FastAPI, and SQLAlchemy for scalable APIs and microservices. - Familiar with CI/CD automation (e.g., GitLab CI/CD, GitHub Actions) and cloud infrastructure on AWS (Lambda, EKS, RDS). - Skilled in integrating blockchain technologies with backend systems, ensuring code quality through unit testing, fuzz testing, and security audits with tools like RustSec and Slither.
Show more
Seniority Architect/Team-lead
Location Poland
Payment Gateways 5yr.
WordPress 5yr.
Laravel 7-9 3yr.
Unity 2yr.
Ant Design 1yr.
...
Developer
Show more
Seniority Expert
Location Caracas, Venezuela
React 4yr.
Node.js 3yr.
...
- 7+ years of experience in the IT industry - Mobile & Web developer - Intermediate English
Show more
Seniority Middle
Location Sapporo, Japan
Product Management
...
Product manager with experience in blockchain development, smart contracts, oracle authenticity, and also creation, implementation, and development of NFT products. - Solid knowledge of blockchain and smart contract. - Strong NFT project management skills. - 10+ years of experience. - Fluent English. - Available ASAP.
Show more
Seniority Senior
Location Pawtucket, United States
Python 10yr.
Django REST framework 10yr.
JavaScript 10yr.
React 7yr.
TypeScript 5yr.
...
Senior Software Engineer with a BSc in Computer Science and over 10 years of experience specializing in Python, Django, JavaScript, React, TypeScript, and cloud platforms like AWS and Azure. Demonstrated ability in creating scalable microservice architectures and developing high-performance backend services, with a keen eye for front-end user experiences. Proficient in deploying applications using CI/CD pipelines and proficient in database management with systems such as PostgreSQL. Successfully evolved ML workflows in FinTech, eCommerce, and AI, enhancing operations and boosting performance.
Show more
Seniority Expert
Location Adelanto, United States
JavaScript
TypeScript
Python
SQL
C/C++/C#
...
The engineer is a proficient Full-Stack Developer and R&D Engineer with a core focus on cutting-edge technologies encompassing JavaScript, TypeScript, Python, SQL, and C++. They have demonstrated expertise in frameworks and technologies like NestJS, Node.js, React.js, Next.js, Blockchain, and Cosmos SDK, coupled with strong database skills in PostgreSQL, MySQL, Redis, and LevelDB. With extensive hands-on experience in DevOps & tooling such as Docker, Git, Linux, Prometheus, and Grafana, the engineer has successfully designed and developed high-availability full-stack applications. Their professional experience includes leading feature development to shorten time-to-market and significantly improving system performance and stability through strategic optimizations. The engineer's deep understanding of RESTful APIs, microservices architecture, and workflow orchestration underscores a commitment to technical excellence in software development practices. Notable achievements include architecting critical blockchain integrations and real-time data streaming functionalities for varied user-intensive platforms. Holding a B.Tech in Computer Science from Medicaps University with a notable academic record further anchors their theoretical understanding and practical application of software engineering principles, securing the foundation for continued professional growth and contribution to technology innovation.
Show more
React 6yr.
Node.js 6yr.
Solidity 5yr.
Next.js 4yr.
...
Innovative Full Stack Web Developer with 6+ years of experience building responsive web applications and 3+ years delivering decentralized applications (dApps) across EVM and non-EVM chains. Proven ability to integrate smart contracts, optimize wallet connectivity (ConnectKit, wagmi, Viem), and deploy scalable backends on AWS. Strong foundation in JavaScript/TypeScript, React, Node.js and DeFi protocols like Uniswap, Aave, and Curve. Experienced in secure, performant infrastructure design across both centralized (AWS) and decentralized (IPFS, Fleek) environments.
Show more
FDD
Unreal Engine
NestJS
AWS
Ant Design
...
Senior Backend Software Engineer with over 5 years of experience in software development, specializing in system architecture and backend solutions across various industries. Holds a B.Sc in Computer Science and professional certifications such as Microsoft AZ 900 and an IBM mastery award. Expertise in developing asynchronous backend systems using NestJS, enhancing application performance with technologies like AWS SQS, Lambda, and implementing multi-queue architectures. Proficient in building scalable microservices with integrated payment and analytics features, utilizing Stripe API, and blockchain technology. Demonstrated capability in optimizing APIs, designing serverless architectures, enabling continuous integration/deployment, and ensuring system compliance and security. Strong proponent of best practices in software development lifecycle, possessing hands-on experience with Kafka, gRPC, Kubernetes, Elasticsearch, and CI/CD pipelines.
Show more
Solidity 6yr.
NestJS 6yr.
TypeScript 6yr.
EVM 5yr.
Zero Knowledge 3yr.
...
Software engineer with over 5 years of development experience, specializing in blockchain platforms, DeFi, and DApps. Demonstrates expertise in Ethereum ecosystem (DEX/CEX integrations, GameFi, lending, RWA, wallets, ZK systems), and diverse blockchain technologies such as Bitcoin, Stellar, and StarkNet. Key competences include Solidity development, smart contracts audit, crosschain NFT systems, and proposing standards like ERC-8006. Possesses advanced knowledge in backend engineering utilizing technologies like Node.js, Python, and .NET, with a strong foundation in computer science from Kharkiv National University of Radioelectronics. Skilled in Full SDLC, devises encryption solutions (zk-proof, homomorphic), and excels in developing auxiliary tooling and technical documentation. Active in OSS, contributing to security (Slither, Echidna, Manticore, Mythril) and infrastructure projects (AWS, DigitalOcean, Heroku).
Show more
DeFi
NFT
...
- 12+ years of experience. - Present talks, explain and give classes about web3 concepts and integrations for blockchain, NFTs, cryptocurrencies, and metaverses. - Bridged the gap between Product/Product Marketing providing data for ‘wants vs. needs’ of dev community for product development. - Executed production strategies and campaigns to more than 500 million users worldwide for all content available on Google Play store. - Led the product development for a multi-million dollar mobile Disney game planning sprints and restructuring the entire project. - Directed product development at five tech and game startup companies simultaneously while getting a Master of Science degree. - Led development of ground-breaking web projects at my own startup using custom-built systems and advanced API integrations. - Upper-intermediate English. - Available ASAP.
Show more
Product Manager
Project Management
...
- 9+ years of experience in IT; - Experience working with Blockchain products; - Deep knowledge and skills in development of fintech products (CeFi/DeFi); - Work experience with Development and work on UI / UX design, and web programming (HTML, CSS); - Familiar with logic controller and CNC machine programming; - Experience in project management and sales - Good skills in organizing the work process in a team using Agile methodology; - Good understanding and vision of product development and its design solution; - Upper-Intermediate English; - Available ASAP.
Show more
Project Management 5yr.
MS SQL Server Management Studio 5yr.
Unreal Engine 4yr.
DigitalOcean 4yr.
...
- Accomplished Software Engineer with over 4 years of experience in developing robust code for high-volume businesses. - In-depth expertise in project management and a proven track record of applying skills in the efficient completion of several large-scale projects. - Highly skilled in SEO integration, digital marketing, and community management, particularly within the crypto and blockchain domains. - Holds multiple certifications in Moderating and Community Management, Project Management, Digital Marketing, and web3 management. - Technical prowess in project management platforms, community moderation tools such as Discord and Telegram, and leveraging social media analytics to enhance follower retention and engagement. - Recognized for successfully leading the Web3 community management, with achievements including a 20% improvement in follower retention through the introduction of new analytic protocols.
Show more
Seniority Middle
Location Manchester, United Kingdom
Ruby on Rails 9yr.
...
● 9 years of Ruby on Rails development ● Extensive knowledge in web and mobile development lifecycle ● Skilled in agile and waterfall project management methodologies, SCRUM experience ● Accountable, communicable, dedicated team player, self-motivated, conscientious, creative individual, well-experienced in troubleshooting, able to learn quickly and effectively ● Upper-Intermediate English ● Computer Systems Analyst (Master's degree)
Show more
Seniority Architect/Team-lead
Location Ukraine
C
C++
...
- Senior Blockchain & Full Stack Engineer with over 15 years of experience in Web and Blockchain development. - Highly skilled Blockchain Professional with hands-on experience building Decentralized Applications and NFT Marketplaces. - Deep understanding of the architecture and protocols of Blockchain and Hyperledger including Bitcoin, Ethereum, L2 solutions, Cross-Chain. - Concentrating on ICO/IEO/IDO projects, helped many Startups and enterprising companies to raise funds and build Ecosystems on the Blockchain. - Quant Developer with a rock-solid understanding of Financial Markets, Quant Trading. - Strong at Solidity, Python, Rust, Web3.js, React, Typescript, Next.js, Node.js, Moralis. - A Veteran at C/C++/C#. - Great teamwork and troubleshooting skills. - Full-time remote, 40+ hours a week. - Upper intermediate English
Show more
Solidity
...
- Software engineer with 10+ years of experience, specializing in Web and Blockchain technologies; - Expertise in Solidity for designing and deploying smart contracts; - Experienced in using Hardhat and Truffle for smart contract development and testing; - Deep abilities in Ethereum ecosystems and Solidity-based architectures; - Skilled in Ether.js and Web3.js for building dApps; - Proficient in designing complex systems, including yield farming and DeFi protocols; - Strong background in full-stack development; - Skilled in Node.js, Express.js, PHP, Java, and Kotlin for backend development; - Experienced in front-end development with Vue.js and EJS JavaScript frameworks; - Proven experience leading projects from concept to deployment across the entire SDLC; - Skilled in mentoring remote teams and collaborating effectively across functions; - Experienced in solution architecture, designing scalable systems, and ensuring smooth integration across platforms.
Show more
Seniority Senior
Location Bulgaria
Python
...
- Python Software Engineer with more than 4+ years of experience in software development - Proven ability to design and build telegram chatbots from scratch, implementing functionalities like search algorithms (CV parsing), voice recording, and payment processing integrations (Stripe, Liqpay). - Has experience integrating GPT with telegram bots - Expertise in database management (PostgreSQL, SQL Alchemy) and data security. - Implemented continuous integration and deployment practices (Jenkins, Docker) for streamlined deployments. - Excellent knowledge of common software engineering practices, like OOP principles, modern design patterns, test-driven development, continuous integration, and continuous deployment
Show more
Seniority Middle
Location Kharkiv, Ukraine
Rust
Solidity
...
-As a senior Programmer and Blockchain developer, with over 6 years of development, I am an expert in NFT Website, NFT Art Generation, and NFT Marketplace, Solidity, Web3, EVM based network chains, Custom smart contracts, ERC20/721, ERC1155, NFTs, IDO's, Bridges Block explorers, UI Web3 Dapps Integration, IPFS. - Smart Contract Development (Solidity/ Rust/ Anchor Framework/ Cosmwasm) - Cardano smart contract by utilizing CosmWasm smart contract by utilizing Rust CosmWasm. - Solanasmartcontractimprovement(Unittest,Solana-program-library,Solana-web3,Raydiumtradeandorca)by utilizing Rust and Anchor system. - Polkadot Relay Chain using Substrate in Rust programming. - Smart contract advancement in networks (Ethereum, BSC, Matic/Polygon) by utilizing Solidity. - Uniswap V2, V3, Curve (Yearn, Convex), Sushiswap, Quickswap, etc. - Written smart contracts for ERC20, ERC223, ERC721, ERC1155, ICOs, airdrop, Vesting, MultiSig, Wallet, etc - DeFi, Dex protocols - Front-end development with Smart contract integration by utilizing Web3, truffle. React (Redux/Thunk/Saga), Typescript, Node js. - NFT minting website andNFT marketplace development(Create a listing by admin, flat&Crypto payment,Bundle Sale/ Bulk Transfers, Drop)
Show more
Seniority Middle
Location Buenos Aires, Argentina
React
Web3
...
- Senior software developer with about 7 years of experience - Web applications for crypto finance (including wallet for Ethereum using ether.js (deposit, withdrawal, staking operations) and web3.js (connect Metamask, get balance, withdraw and deposit tokens) - Maintaining web applications with Front-end jQuery, Vue.js, React.js, React Native, Angular.JS, Angular 2+ and PHP Laravel, WordPress - Hands-on experience of both working as a single developer and being a part of big Agile teams.
Show more
Seniority Senior
Location Kharkiv, Ukraine
1 2 3 4