Hire Vetted Blockchain Engineers at Upstaff - Page 2

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.
Solidity
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- 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.
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Seniority Senior
Location Bulgaria
JavaScript 5yr.
Swift 5yr.
FDD 5yr.
Node.js
React
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Software engineer with 9+ years of experience, excelling in full stack development with expertise in JavaScript, Swift, and iOS development. Proven track record of leading successful projects, including winning multiple hackathons and developing robust blockchain-based solutions. Demonstrates strong technical leadership, having managed diverse engineering teams and fostering agile best practices. Well-versed in various technologies like Node.js, React.js, Firebase services, Ethers.js, Web3.js, and AWS, with a solid foundation in computer science from Universidad Nacional del Nordeste. The engineer's proficiency in building scalable systems for music streaming, live video monitoring, and blockchain integration positions them as a valuable asset to any team seeking deep technical expertise and innovative solutions.
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Blockchain 7yr.
Smart Contract 7yr.
Solidity 6yr.
Dapp 6yr.
DeFi 6yr.
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Blockchain Developer | Web3 Engineer | Smart Contract Specialist Experienced Blockchain Developer with a deep understanding of decentralized applications (dApps), smart contracts, and blockchain architecture. Skilled in Ethereum, Solana, and Binance Smart Chain (BSC), with expertise in Solidity, Rust, and Web3 integrations. Passionate about building scalable, secure, and efficient blockchain solutions that drive innovation in DeFi, NFTs, and enterprise blockchain applications.Key Skills & Expertise: ✅ Blockchain Development: Smart contracts, tokenomics, DeFi protocols, NFT marketplaces ✅ Smart Contract Programming: Solidity, Rust, Move, Cairo ✅ Fullstack Web3 Development: Node.js, React, Next.js, Nest.js, Web3.js, Ethers.js ✅ Blockchain Frameworks: Ethereum, Solana, BSC, Polygon, Hyperledger ✅ Security & Auditing: Smart contract security, cryptography, vulnerability mitigation ✅ Infrastructure & DevOps: IPFS, The Graph, Oracles, Infura, Alchemy, Hardhat, Truffle ✅ Consensus & Protocols: Proof of Work (PoW), Proof of Stake (PoS), Layer 2 scaling
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Seniority Senior
Location United States
React Native
React
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- React/React Native Engineer with almost 6 years of professional experience - Experience with Amazon/Amplify/S3/Code push - Successfully developed both iOS and Android applications using React Native - Developing React/React Native apps that interface with Restful APIs - Experience with React/Redux/Third-Party API Integrations - Experience with GraphQL/Apollo - Upper Intermediate English - Available ASAP
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Seniority Senior
Location Armenia
PHP 9yr.
JavaScript 9yr.
MySQL 9yr.
Solidity
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- 10+ years experience as a Full-Stack Developer with of developing robust web applications and services, including extensive experience in both frontend and backend technologies; - Technical proficiency with PHP and MySQL for server-side development, advanced JavaScript utilization on the client side; - Strong abilities with blockchain technology engagement, including smart contracts and wallet development using Solidity, Hardhat, Truffle, WalletConnect, and Metamask SDK; - Experienced with libraries Web3.js, and Ethers.js; - Ability to work Ethereum Blockchain, Binance Smart Chain (BSC), with different wallets including MetaMask; - Adept at working with a variety of frameworks and languages beyond core competencies, such as Laravel, Solidity, Node.js, and C++; - Up-to-date with modern practices, possessing comprehensive experience in codebase upgrades, performance optimization, and integrating third-party APIs; - Successfully led a development team, demonstrating strong leadership and project estimation skills.
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Seniority Senior
Location Ukraine
Python 7yr.
Solidity 6yr.
Solana 4yr.
JavaScript 3yr.
Rust 2yr.
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- 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.
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Seniority Architect/Team-lead
Location Poland
Go 3yr.
Python 1yr.
TypeScript 1yr.
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Software Developer | Backend & Web3 Engineer | Golang, TypeScript, PythonResults-driven software developer with 3+ years of experience in building scalable backend systems, financial infrastructure, and Web3 solutions. Proficient in Golang, Python, TypeScript, C++, and cloud-native technologies (AWS, Kubernetes, Docker).🔹 Currently at Syndr, designing high-performance exchange servers, optimizing data pipelines, and developing Web3 SDKs. 🔹 Previously at Epifi, led UPI-based financial workflows and transaction processing using Temporal. 🔹 Ex-Smarsh, where I improved database architecture and query performance for SaaS compliance solutions.Passionate about distributed systems, blockchain, and high-performance computing. Active contributor to open-source and tech communities.📌 GitHub: AbhinitKumarRai | LinkedIn: Abhinit Rai
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Project Management 5yr.
MS SQL Server Management Studio 5yr.
Unreal Engine 4yr.
DigitalOcean 4yr.
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Software Engineer with 4 years of experience specializing in high-volume business code development and project management. Expertise in SEO integration, digital marketing, and Web3 community management with a strong background in using project management platforms and community moderation tools. Holds certifications in Community Management, Project Management, Digital Marketing, and Web3 management. Recognized for leading Web3 community initiatives, improving follower retention by 20% with analytical protocol enhancements. Technical skills include Project Management (5 years), Unreal Engine, DigitalOcean, and MS SQL Server Management Studio (each 4 years), along with proficiency in iOS Core Graphics and CSP.
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Seniority Middle
Location Manchester, United Kingdom
Go 14yr.
React
JavaScript
PostgreSQL
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- Certified Senior Go Engineer ( 12 years with Go, 19 years in Software Engineering) with experience in software engineer, team lead and software architect roles. - Master’s Degree in Computer Science - Designed and implemented a scalable multi-microservice backend for an enterprise AdTech CRM, integrating 10+ third-party services and streamlining client management operations. - Built and deployed a billing system for a money exchange platform, integrating third-party payment systems and delivering a user-friendly web interface for seamless transactions. - Optimized data processing pipelines by implementing quantiles on streams, enabling real-time analytics and supporting large-scale data operations for scientists and business stakeholders. - Extensive background in data processing and reporting.
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Seniority Expert
Location Kharkiv, Ukraine
Node.js 8yr.
Web3.js 4yr.
Solana 2yr.
EthereumJS 2yr.
React
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- Full-Stack Engineer with over 8 years of experience specializing in Web2 and Web3 technologies, blockchain development, and Full-Stack architecture. - Has 4 years of experience working with web3, implementing blockchain solutions using Ethereum, Solana, and smart contracts. - Proven expertise in tokenization, NFT integration, and cryptocurrency transactions for real estate, voluntary donation, and other industries. - Expertise in Node JS, Nest JS, and RESTful APIs, with proficiency in React JS for frontend development. - Strong experience with databases like PostgreSQL, Redis, MongoDB, and DynamoDB. - Well-versed in cloud services, including AWS and GCP, and experienced in container orchestration with Kubernetes. - Proficient in CI/CD using Jenkins, GitHub Actions, Bitbucket Pipelines, and Terraform. - Familiar with Nginx for web server management and ensuring smooth application deployments.
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Seniority Senior
Location Warsaw, Poland
Rust 2yr.
Solidity
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- Engineer who has 6+ years of experience with many programming languages, frameworks, and platforms; - 2+ years experience with developing smart contracts on Rust; - Solid skills with Solidity; - Working experience in building an NFT marketplace platform on Polygon and Binance Smart Chain using ERC-721 and ERC-1155; - Experience with ether.js, web3.js, and JS/TS frameworks; - Familiar with blockchain Ethereum, Binance, Tron, Solana, Polkadot, Tezos, Polygon, Huobi ECO chain, etc; - Deep knowledge in implemented Metamask, Torus, and other wallets to increase user experiences with the web apps; - Advanced English; - Available ASAP.
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Seniority Senior
Location Singapore
Web3
Node.js
NestJS
PostgreSQL
AWS
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- Full Stack Developer with strong blockchain skills. - Over 10 years of experience in IT. - More than 7 years of experience with Node.js and Nest.js. - Strong skills with Express.js. - Over 7 years of experience with PostgreSQL. - In-depth knowledge of Docker and Kubernetes. - Experience with Angular. - Experienced in blockchain projects since 2017. - In-depth knowledge of blockchain integration into the backend. - Upper-intermediate English. - Available ASAP.
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Seniority Senior
Location Ukraine
NFT 5yr.
Smart Contract
FDD
CI/CD
SOLID
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Accomplished Blockchain Developer with over 5 years of expertise in designing and implementing advanced applications with a focus on blockchain technology, smart contract and dApp development. Strengths include hands-on experience with PoS/PoA sidechains, Ethereum, Binance, Tron, and a plethora of ERC standards, backed by robust skills in Golang, JavaScript, Solidity, and cloud technologies. Proficient in fostering innovative database design, API development, and server management, which are further enhanced by a seasoned track record in deploying blockchain solutions on AWS and GCP. Distinguished by participation in high-profile projects like decentralized exchanges and NFT platforms, showcasing not only technical prowess but also effective collaboration with cross-functional global teams and deployment of CI/CD pipelines.
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Seniority Senior
Location Indore G.P.O., India
PHP
NestJS
microservices architecture
TypeScript
React
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Senior Full Stack Developer with a Master’s in Computer Science and a depth of experience in front/backend technologies across multiple domains. Practical knowledge of Python, Django, Next.js, NestJS, and a robust foundation in PostgreSQL. Proven capability in leading development projects, optimizing database schemas, and leveraging CI/CD pipelines with Docker and Kubernetes. Skilled in Agile methodologies, project management, and UI/UX design paired with a substantial background in IoT solutions, showcasing versatility and technical prowess. Recognized for streamlining operations, reducing costs through automation, and advancing retail technology platforms.
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Seniority Senior
Location Frankfurt, Germany
Go 2yr.
JavaScript
Rust
Node.js
NestJS
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- 6+ years experience as a Software Engineer; - 2 years experience working with Go; - Deep abilities working with Rust; - Good knowledge of creating smart contracts; - 4 years experience working with JavaScript, React, Next.js, Redux; - Experience working with TypeScript; - 3+ years of experience working with Node.js; - Good skills working with NestJS; - Experience working with Python, Swift, Kotlin, Flutter, Express; - Experience working with AWS; - Experience working with PostgreSQL, MongoDB; - Good skills on team lead - led ~12 people; - Took part in all aspects of product design and engineering, from marketing, and business investigation to the MVPs for start-ups, pitch decks, and mock-ups; - Upper-Intermediate English.
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Seniority Senior
Location Estonia
AA RPA
Business Analysis
Power Automate
Visual Basic .NET
Robot Framework
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Software engineer with 3+ years of experience in RPA and software development. Holds a Bachelor's in Mechanical Engineering and a Master's in Information Systems. Proficient in Power Automate, UiPath, Power Apps, and has extensive work with automation tools across E-Commerce, Healthcare, Finance, and Banking sectors. Technical expertise in scripting and programming languages such as VB.NET, ASP.NET, Java, JavaScript, Python, and SQL. Recognized for significant contributions to client project success and process efficiencies in professional tenure. Skilled in SDLC, RPA lifecycle, cloud services, and migrations from UIPath to Power Automate, indicating versatility and readiness for complex technical challenges.
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Flutter 4yr.
GCP 4yr.
Firebase 4yr.
Go
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* 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.
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Seniority Middle
Location Bamenda, Cameroon
Rust 1yr.
C/C++/C# 1yr.
Solana
Axum
Tokio
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Software Engineer with expertise in backend development, blockchain technology, and big data, boasting a solid foundation in computer science from Ukrainian Catholic University. Holds a strong junior/middle experience level, with hands-on Rust, C++, and a gambit of modern technologies such as Solana, Axum, and Kafka. Proven track record of developing robust solutions for cryptocurrency swapping and NFT architecture, time-series data manipulation, and digital media copyright solutions. Notable achievements include contributions to open-source projects, and winning a national programming tournament. Fluent in advanced software engineering paradigms and well-versed in real-time streaming and machine learning library development.
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Seniority Junior
Location Lviv, Ukraine
Go
Solidity
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- Fast-paced, high-quality, detail-oriented, and self-motivated developer with more than 10 years of experience in the IT industry. - I use the TDD approach for designing the architecture and implementing scalable and maintainable web apps/services. - I have been working on a bunch of projects and meanwhile, I worked in several positions across frontend developer, backend developer, full-stack developer, and lead engineer. - Bridge Smart Contract which is for transferring tokens across networks. - NFT Dapps such as madlab, Art Basel, Fateful Youth - eWallet App and GSM e-commerce product. - Smart contracts in complex Defi and DEX structure - Blockchain networks including Ethereum, BSC, Polygon, and Solana. - Deploy and work on various kinds of tokens - ERC20, ERC721, ERC721A, ERC1155. - Cross-chain smart contracts using LayerZero - NFT market smart contract for auction and offer with lazy minting - Proxy smart contract - NFT marketplace Dapp using Venly - Available: ASAP
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Seniority Senior
Location Hong Kong
C
C++
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- 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
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Seniority Senior
Location Canada
Rust
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- 5+ years of experience in blockchain development - Advanced English - Available ASAP
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Seniority Senior
Location Sydney, Australia
Rust
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- 15 years experience with programming languages VB, C/C++; - First projects - embedded devices on AVR/STM32/ESP and applications for windows. - But since ~2017 I'm using an embedded experience very seldom and mostly developing software for Linux on C++. - Since 2022 I have switched the Rust and don't want to use C++ as the main language anymore. - Intermediate English.
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Seniority Senior
Location Ukraine
Rust
Solidity
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-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)
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Seniority Middle
Location Buenos Aires, Argentina
Node.js 5yr.
Go 3yr.
Solidity
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- Fast-paced, high-quality, detail-oriented, and self-motivated developer with more than 10 years of experience in the IT industry; - I use the TDD approach for designing the architecture and implementing scalable and maintainable web apps/services. - I have been working on a bunch of projects and meanwhile, I worked in several positions across frontend developer, backend developer, full-stack developer, and lead engineer; - In-depth skills develop smart contracts on Solidity; - Good skills working with Go; - 3 years experience with Rust; - 2 years experience with Substrate; - Smart contracts in complex DeFi and DEX structure; - Bridge Smart Contract which is for transferring tokens across networks; - Proxy smart contract; - eWallet App and GSM e-commerce product; - Blockchain networks including Cosmos, Ethereum, BSC, Polygon, Avalanche and Solana; - 5+ years experience with Node.js; - Deep skills working with Apollo GraphQL; - Good abilities working with Hardhat framework; - Deploy and work on various kinds of tokens - ERC20, ERC721, ERC721A, ERC1155; - Cross-chain smart contracts using LayerZero; - NFT Dapps such as madlab, Art Basel, Fateful Youth; - NFT market smart contract for auction and offer with lazy minting; - NFT marketplace Dapp using Venly; - Available: ASAP.
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Seniority Senior
Location China
Rust 3yr.
Solidity
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- 3 years of experience with Rust - Efficiently deployed web application powered by rust backend. - Built innovative microservices and Web Services using Web Actix and diesel. - Engineered and maintained modern web assembly application using Rust . - Developed web application using sqlx and Web Actix. - Strong front-end interaction skills with Solidity transactions. - Highly qualified knowledge of working with Metamask wallet, transactions, and fees for them. - Upper-Intermediate English. - Available ASAP.
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Seniority Middle
Location Nigeria
Rust 2yr.
Solana
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- 7+ years experience as a web developer; - 2 years of experience with developing smart contracts in Rust; - Deep skills working with Solana blockchain; - Good abilities working with Anchor; - 5+ years experience working with C#; - Good knowledge of JavaScript, and TypeScript; - 2+ years experience working with Angular framework; - Experience with Node.js, and NestJS; - Good abilities working with .NET; - Experience working with Docker; - Upper intermediate English.
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Seniority Senior
Location Kyiv, Ukraine
Rust
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- More than 17 years of commercial experience in IT; - Experience cooperating with clients worldwide and building products related to various spheres: e-commerce, real estate, custom CRM, trading, social media and many more. Product tech design and full cycle of development and support; - Deep experience in development web applications using Ruby on Rails, Rust, Java, JavaScript, Go; - Strong experience of AWS, Azure Clouds, Google Clouds; - Experience in team leading and CTO; - Upper-Intermediate English; - Available: ASAP.
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Seniority Senior
Location Ukraine
Rust
Solana
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- 8 + years experience in IT; - 5+ years experience working with Rust; - Good skills in creating smart contracts for Solana and NEAR Blockchains; - Experience in building a bridge to Casper Network; - Experience working with Filecoin, Zero Knowledge modules, and Fuel Blockchain; - Deep abilities with MySQL, PostgreSQL, MongoDB; - Experience working with Python, Java, PHP, Scala, and Spring; - Good knowledge of AWS ElasticSearch; - Experience working with Docker and Kubernetes (K8s); - Experience working with DeFi and DEX projects; - Deep skills with Apache Cassandra and Apache Spark; - English: Upper-Intermediate.
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Seniority Senior
Location Czech Republic
Rust 2yr.
Python 2yr.
Actix Web
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- 4 years of development experience, including 2 years of Rust development and 2 years of previous Python backend development experience. - Development and design of high-load fintech solutions using Rust and Python - Experience with Rust microservices (Actix Web, Rocket, AWS Lambda) - Upper-Intermediate English
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Seniority Middle
Location Kyiv, Ukraine
Elixir 3yr.
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- Started career as a Ruby on Rails developer and worked exclusively with it for around 4 years, after which switched to Elixir and have 3.5 years of commercial experience with it - Last version engaged with RoR: 5.2 - Proficient in Phoenix / Elixir, Ruby on Rails, and AngularJS, focusing on performance improvements, test coverage, and refactoring. - Foundational knowledge of Haskell and Plutus for writing smart contracts on the Cardano blockchain. - Upper-Intermediate English
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Seniority Middle
Location Serbia
TypeScript 10yr.
JavaScript 10yr.
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- More than 10 years of experience in developing applications using JavaScript and TypeScript - Experience with a setup a blockchain IoT network using the Hyperledger(infrastructure) - Built a system and smart contracts, that are deploying into ETH network for digital signing of contracts for each deal of customers - Setup an ETH explorer - Build a web game, based on Solana, NFT tokens - Experience with a migration from a monolithic architecture to microservices, it helped to spread jobs between teams and increased development speed, also here grew and lead the most productive team in the company (11 people) - For the KYB/KYC platform startup based in Estonia architectured and implemented a whole app with Nest.js and React, it helps to build scale and flexible application, CQRS architecture - Built processes for project lifecycle from development to release, CI/CD, started and scaled team, held workshops for the team - Built a headless modern framework for frontend that based on React, swiftly increased a development speed - Solved problem with a slow project building, increased speed x7.7 (210s ->27s) - Supported a quite aging project and migrated some parts to microservices, wrapped into Kubernetes - Optimized database queries, increased x3 - Suggested a better structure for a codebase for GraphQL and React, increased development speed - Architecture & Tech Lead at Node.js Department
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Python
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- 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
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Seniority Middle
Location Kharkiv, Ukraine