Hire Vetted Blockchain Engineers at Upstaff - Page 1
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.
Blockchain
All
Web Application
Data and Analytics
Operations and Cloud
Mobile Application
Digital Platforms
Blockchain
Design and Creative
Quality Engineering and Testing
Delivery Management and Analytics
Desktop Software
Writing and Translation
Marketing and SEO
Scripting and Automation
Embedded Systems
Low-Code
GameDev
Industrial Engineering
JavaScript 8yr.
React 8yr.
TypeScript 5yr.
Node.js 5yr.
Next.js 3yr.
- 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.
Architect/Team-lead
Ukraine
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).
Expert
Mexico
Python 5yr.
Django 3yr.
Mobile development
Flask
API
- Python Developer with 5+ years of experience in backend development and automation: Django (3 years), Flask, and Fast API for web application development;
- Maintaining and supporting production systems using FastAPI and SQLAlchemy, API integrations including financial services and crypto platforms;
- Built and supported Telegram bots and automation tools for business operations;
- 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.
Middle
Ternopil, 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
Senior
Ukraine
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;
Senior
Ukraine
$55/hr
$8000/month
$8000/month
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
Senior
United States
JavaScript 5yr.
Web3.js
React
WebRTC
- 5+ years of experience as a Front-end JavaScript Developer;
- 5+ years of experience in React.js;
- Proficient in Solana Blockchain operations, including managing deposits, executing transfers, creating Phantom wallets, and handling contract call interactions;
- Strong abilities working with Web3;
- Deep experience in Next.js technology;
- Experience with WebRTC, Soket.io;
- Good knowledge of Tailwind CSS, Bootstrap, and Chakra UI;
- Experience working with Redux, and Docker;
- Familiar with Node.js;
- Proficiency in testing frameworks like Jest and Cypress;
- E-commerce, web, and mobile applications, including learning platforms, chatbots, dApps, and cryptocurrency wallet extensions.
Senior
Castel San Giovanni, Italy
TypeScript 5yr.
JavaScript 5yr.
Node.js 5yr.
React 5yr.
Next.js
Software Engineer with 4 years experience, including FAANG tenure, excels in Web3, blockchain, and frontend technologies. Spearheaded development of high-traffic React and Next.js applications, enhancing performance metrics by 35%. Pioneered end-to-end decentralized solutions encompassing DeFi and NFT domains with strong proficiency in EVM, Solidity, and full-stack Web3 practices. Recognized for applying FAANG engineering standards to startup ecosystems, ensuring scalable and maintainable code. Holds a Bachelor's in Computer Science from Lviv Polytechnic National University, demonstrating a robust foundation in technical academia and a commitment to rigorous engineering methods.
Senior
Chervonohrad, Ukraine
Rust
Azure Blockchain
Smart Contract
SOLID
Web3
Accomplished Full Stack Blockchain Developer with over 9 years of experience in the industry, specializing in the integration of Web3, Rust, Solidity, and other technologies to create innovative blockchain solutions and decentralized applications (DApps). Expertise in front-end and back-end development evidenced by projects like BIMA and Bitcross, with skills in JavaScript, React JS, Node.js, and database management. Adept in building robust smart contracts on various blockchains such as EVM, Solana, and Arch Network, having contributed to key projects including Bitflow, Nimbus, and Trustbet. A solid computer science foundation from Rajiv Gandhi Technical University bolsters a career marked by technical proficiency and readiness for team collaboration as well as independent work. Proven track record of leveraging full-stack development capabilities and deep blockchain knowledge to meet and exceed project requirements.
Senior
Ahmadabad, India
JavaScript 4yr.
TypeScript 4yr.
React 4yr.
Ext JS 4yr.
Node.js 4yr.
Expert Full-stack Developer with advanced capabilities in TypeScript, React/Next.js, and Node.js. Possesses a Bachelor's in Computer Science and has taken specialized courses in Full-stack development and blockchain technologies, reflecting a commitment to continual learning. Proven track record in building and scaling high-load applications, particularly in the healthcare, media, and decentralized tech sectors. Demonstrates strength in creating responsive UIs, implementing complex back-ends, and ensuring high code quality through rigorous testing. Technical skill set includes modern JavaScript frameworks, RESTful and GraphQL APIs, microservices, and cloud services (AWS, GCP), supplemented by practical knowledge of SQL/NoSQL databases, Docker, and CI/CD pipelines. Fluent in essential industry practices and proficient in English and several other languages, making for a versatile asset in international and cross-functional teams.
Middle
Germany
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.
Senior
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).
Senior
Lviv, Ukraine
Solidity
React
Blockchain
Smart Contract
Architect/Team-lead
United States
Blockchain
I am a seasoned blockchain developer with proven experience in building, optimizing, and scaling projects across multiple layers and ecosystems.
Beyond development, I also bring strategic connections and marketing expertise to help projects succeed from launch to adoption.
Senior
Odesa, Ukraine
Java
C/C++/C#
PL-Sql
JavaScript
A well-rounded software engineer with a National Diploma in IT and diverse experience across several tech domains. Engineer possesses expertise in a range of programming languages like Dart (Flutter), Java, C#, and PL/SQL, and is also proficient in data automation tools including Power BI, Tableau, and VBA. They have a proven track record in database administration, test automation, and system integration, demonstrated by their work with enterprise clients and contributions to national innovation projects. Notably, the engineer has developed AI-powered platforms and fintech solutions, showing a commitment to innovation and problem-solving. Their methodologies include Agile and SDLC, ensuring efficient and effective project execution. With certifications in modern frameworks and technologies like Hashgraph and BDD testing, the engineer's technical acumen is well-established.
Junior
South Africa
SOLID 8yr.
DeFi
Cross Chain Bridges
Smart Contract
Azure DevOps
Dynamic Senior Blockchain Developer with over 8 years of experience in building and deploying enterprise-grade blockchain applications. Proficient in Solidity and Rust, expertly crafted DeFi protocols managing $75M+ TVL and facilitated $100M+ in cross-chain volume. Proven leadership in guiding engineering teams to deliver high-performance technologies such as a network bridge for Solana-Ethereum interoperability and Cosmos SDK chains. Innovated within the blockchain space by implementing TSS/MPC for secure transactions, designing advanced Layer 2 scaling solutions, developing DEX platforms, and ensuring system robustness through comprehensive DevOps practices. Educated in Computer Science from Sonoma State University, this engineer brings a wealth of knowledge in blockchain frameworks and protocols, programming languages including Solidity, Rust, and Go, as well as cloud infrastructures like AWS/GCP, underpinned by a command of software development methodologies.
Expert
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.
Expert
Adelanto, United States
Python 5yr.
TypeScript 5yr.
C/C++/C#
Robot Framework
Dart
Software engineer with a strong focus on AI integration and full-stack web solutions. A proven track record in building AI-powered tools and automating core processes, coupled with expertise in cross-platform development and containerization. Extensive experience with Python, Docker/Nginx, and deploying reliable APIs. Actively pursuing a Bachelor's in Computer Science and excelling in hands-on roles such as Software Research Engineer. Achievements include reducing log review time by 70% and improving customer agents' response rate from 45% to 85%. Adept in languages like C/C++, JavaScript/TypeScript, and possesses advanced skills in frameworks like Django and ReactJS.
Middle
Lagos, Nigeria
Dart 2yr.
Facebook Auth 2yr.
Clean Architecture
MVVM
Packet Tunnel Provider
Software engineer with specialized expertise in Flutter development for multi-platform applications. Experienced in leading cross-functional teams and optimizing app performance, with hands-on experience in architecture and advanced project management systems. Technical proficiency in Dart, along with familiarity in C++, JavaScript, TypeScript, and a variety of Flutter frameworks and architectures. Proven record in developing high-traffic, secure applications with a focus on user experience, contributing to substantial growth rates in user base and sales. Strong foundation in computer science with a biotechnology and pharmacy degree, underpinned by effective problem-solving skills showcased through the completion of 200+ Leetcode problems.
Middle
Alexandria, Egypt
Smart Contract 8yr.
Blockchain 6yr.
Rust 5yr.
Solidity 5yr.
Go
Software engineer with a Bachelor’s in Computer Science and 8 years of experience specializes in blockchain development, smart contracts, and DApps, mainly in Solidity and Rust. Demonstrated expertise in Ethereum and Solana ecosystems with significant projects such as a fully-featured NFT marketplace and the first multichain swap protocol. Excelled in developing secure, scalable solutions with 99% test coverage in Rust, contributing to the advancement of decentralized protocols. Adept in various technologies including Go, Move, Web3, DeFi, and smart contract auditing, positioning as a valuable asset for blockchain-centric roles.
Senior
Zagreb, Croatia
RESTful API
JavaScript
TypeScript
Seasoned Product Manager and former Research Staff with extensive IT experience, specializing in accessibility and adept in modern programming languages and tools. Notable for leading the development of assistive technology products and contributing to inclusive technology initiatives. Proven experience in API optimization, problem-solving in server-client communication, and enhancing application security using Azure Key Vault. Strong educational foundation with a Bachelor of Engineering in Computer Science and an MBA in Systems. Recognized for technical leadership, strategic project management, and analytical prowess in high-stakes environments.
Expert
Hyderabad, India
Solidity 5yr.
Java 5yr.
Solana 2yr.
- 7+ years of experience building scalable Web3 applications and DeFi platforms with Solidity, Rust, and Java in Blockchain, DeFi, NFT Tokenization, Fin-Tech domains
- Strong expertise in smart contract development across Ethereum, Polygon, Solana, and Hedera, using ERC standards, Anchor, and Foundry
- Designed and optimized zero-knowledge circuits (ZKPs) and decentralized identity systems (DID) for privacy-preserving applications
- Integrated oracle networks (Chainlink, Pyth) and implemented advanced DeFi mechanics: yield farming, auto-compounding, AMMs, and on-chain governance
- Developed secure and gas-efficient smart contracts using EIP-712, proxy patterns, and off-chain signature schemes
- Built robust backend and API layers (Node.js, Java, GraphQL) with optimized database performance in PostgreSQL and MongoDB
- Delivered full-stack dApps with seamless wallet integration (MetaMask, WalletConnect, HashPack) and deployed them on Vercel / AWS
- Contributed to CI/CD, testing, and code quality using Hardhat, Slither, TestContainers, Jenkins, and GitHub Actions
Senior
Warsaw, Poland
Solidity 4yr.
Solana 1yr.
- Blockchain Developer with 5 years of experience building decentralized applications (dApps) using Solidity and Rust across EVM-compatible chains (Polygon, BSC, Base) and Solana.
- Proficient in frameworks such as HardHat and Anchor for developing, testing, and deploying smart contracts, with hands-on experience integrating wallets like MetaMask and working with DeFi protocols including Uniswap, Aave, and Alpaca Finance.
- Experienced in implementing and customizing token standards such as ERC-20, ERC-721, ERC-721A, and ERC-1155, as well as secure signing mechanisms via EIP-712.
- Skilled in smart contract auditing and fuzz testing using tools like Slither, Mythril, and RustSec, ensuring robust and secure codebases.
- Adept in version control and collaboration using Git and GitHub, with a focus on maintainable and testable code.
- Experienced in blockchain data indexing and integration using The Graph/Subgraphs, enabling efficient access to on-chain data across applications.
- Well-versed in cross-chain development and decentralized identity (DID), contributing to secure, scalable, and user-centric Web3 ecosystems.
Senior
Warsaw, Poland
Rust 2yr.
Solana 2yr.
- Blockchain Developer with a 5-year background in financial technologies, specializing in Crypto, De-Fi, and NFT domains.
- Exhibits proficiency in several programming languages, including Solidity, Rust, JavaScript, and TypeScript.
- Key technical experience encompasses Ethereum, Solana, IPFS, and advanced blockchain development tools and practices.
- Has experience in smart contract architecture design, blockchain integration, and secure transaction implementation across multiple projects, such as decentralized gaming platforms, NFT collections, and crypto exchanges.
- Demonstrated capabilities in both backend technologies (Node.js, Express.js) and cloud infrastructures (AWS suite)
- Upper-Intermediate English
Senior
Warsaw, Poland
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.
Senior
Vietnam
Python 8yr.
Django 7yr.
Django REST framework 7yr.
SQL
Backend Software Engineer with over 8 years of experience, specializing in Python, Go, and cloud-native technologies. Expert in API development, system architecture, and integrating distributed systems within research, regulated, and blockchain fields. Proficient in Python, Go, SQL, Docker, Kubernetes, AI/ML tools, and cloud services (GCP, AWS). Has led backend development for decentralized applications, real-time monitoring, file-sharing systems, and automated SDLC focusing on security and performance. Demonstrates proficiency in DevSecOps, regulatory compliance, and modern backend frameworks.
Senior
South Africa
FPGA
VHDL
C/C++/C#
Python
Embedded Systems
- Seasoned FPGA and embedded systems engineer with 10+ years of experience, and a track record of architecting and implementing complex hardware and software solutions;
- Expert knowledge in VHDL, FPGA, CPLD, MCU, and SoC development, with proficiency in tools like Intel(Altera), Xilinx, and Modelsim;
- Strong expertise in cryptographic acceleration, RADAR systems, digital signal processing, and PCB design;
- Experience in leading a development team for a cryptography acceleration project and implementing advanced algorithms in various domains;
- Robust background in electronic device development and embedded programming in C and Python.
Expert
Kyiv, Ukraine
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.
Junior
MS SQL Server Management Studio
Unreal Engine
Linea
Azure VM
Seasoned Head of Engineering with 8+ years of experience in driving technical strategy and leading multidisciplinary development teams. Expertise in AI, blockchain, and full-stack custom software solutions including MERN stack, PHP, and MySQL. Proven track record at Macromodule Technologies, shaping engineering culture with agile principles and maintaining focus on delivering business-aligned, future-ready software products. Holds a Bachelor of Science in Computer Science and has previously elevated backend systems at Dtech Systems and spearheaded full-stack projects at ArhamSoft. Known for integrating emerging technologies and establishing engineering KPIs that foster continuous improvement and technical excellence.
Expert
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.
Middle
Manchester, United Kingdom