Hire Vetted Web Application 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.
Web Application
All
Web Application
Data and Analytics
Cloud and Operations
Mobile Application
Blockchain
Digital Platforms
Design and Creative
Quality Assurance
Project Management
Desktop Application
Marketing and SEO
Scripting and Automation
Embedded Systems
Writing and Translation
Low-Code and No-Code
GameDev
Industrial Engineering
Kotlin 5yr.
Java 5yr.
Ivan is a Lead Kotlin/Java Engineer with solid experience in backend and Android development. He builds reliable and maintainable applications, works well with cross-functional teams, and enjoys improving codebases and system architecture. Ivan is comfortable mentoring others and contributing to both mobile and backend projects, making sure they run smoothly and efficiently.- Software Engineer with 5+ years of experience in developing Android and backend solutions in the healthcare, fitness, and automotive industries;
- Strong Skills with Kotlin, Java, and TypeScript, creating Android applications on Jetpack Compose, Firebase, Android SDK, KMM, as well as backend solutions on Spring Boot (and basic experience with Node.js / React for integrations and prototypes);
- Experienced with AWS (Serverless, Lambda, S3, API Gateway) and GCP, builds cloud infrastructure, and is undergoing Google Cloud certification;
- Skilled with Firebase as a backend platform;
- Experience CI/CD, Docker, GitHub Actions, works according to Agile principles;
- Interested in implementing AI models in production solutions.
Laravel 5yr.
Vue.js 5yr.
MySQL
* 7 years of experience in a Web Development team environment. Experience with Web Technologies: HTML5, CSS3, PHP, Symfony, Laravel, Javascript, Vue.js and jQuery.
* Working knowledge of Data Formatting Technologies: XML, XSL, and JSON. Experience with Web Servers: Apache and NGINX.
* Strong understanding of Utility Languages: FTP, SSH, Shell Scripting.
* Working knowledge of Content Management Systems: WordPress, modX. Experience with Common Development tools (Git, SVN, etc).
PostgreSQL 5yr.
REST 5yr.
TypeScript 3yr.
Python
Go
* Master’s Degree in Computer Science
* 19 years in Software Engineering: Python, Kotlin, Swift, C/C++, and TypeScript in software engineer, team lead, and software architect roles.
* Data processing with numpy, pandas, moving pandas, airflow, spark,and nifi.
* 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. Good abilities in SCM tools like Git, and in multi-threading and networking. Strong skills in Docker, gRPC;
* Cloud service platforms: AWS, Google Cloud, and MS Azure;
* Experience with DBMS, PostgreSQL, MySQL, MongoDB;
* Certificated knowledge of Blockchain;
* Certified Senior Go Engineer (12 years with GoLang).
Scala
Software Engineer with proficiency in data engineering, specializing in backend development and data processing. Accrued expertise in building and maintaining scalable data systems using technologies such as Scala, Akka, SBT, ScalaTest, Elasticsearch, RabbitMQ, Kubernetes, and cloud platforms like AWS and Google Cloud. Holds a solid foundation in computer science with a Master's degree in Software Engineering, ongoing Ph.D. studies, and advanced certifications. Demonstrates strong proficiency in English, underpinned by international experience. Adept at incorporating CI/CD practices, contributing to all stages of the software development lifecycle. Track record of enhancing querying capabilities through native language text processing and executing complex CI/CD pipelines. Distinguished by technical agility, consistently delivering improvements in processing flows and back-end systems.
XSLT 10yr.
Python
XML
- 12+ years of experience in IT
- 10+ years of experience with XSLT
- Writing, testing and maintaining the XSLT code that applies some filtration and conditions on XML
- Converting IATA NDC Standard XML Content format into IATA NDC Standard XML format using XSLT
- Familiar with many processing engines like Saxon (Java) - libxslt (C) - Python’s package
- Upper-intermediate English
- Available ASAP
AEM
- 14 years of AEM experience in design, development, integration, and delivery of small to large-scale enterprise-level applications.
- An experienced solution architect with a keen interest in business domains, hands-on in technology-based solutions, and a strong focus on delivering measurable value.
- Industry Experience: Vast industry experience covering aviation, telecommunications, media, finance, retail, mutual funds, and services sectors.
- Technical skills: Best-in-class analytical and problem-solving skills with a track record of on-time and within-budget delivery.
- Soft skills: Ability to build strong personal and professional relationships using excellent interpersonal skills.
- E-commerce and AEM Expertise
- Certificated Adobe Experience Architect, Components Developer, ManagerAreas of expertise include:
- Digital transformations including Content Management Systems (CMS) like Adobe Experience Manager (AEM/CQ5).
- Application/Software development right from inception to implementation
- Implementation strategies, planning, and execution
- Agile methodologies such as continuous integration and continuous delivery, features/domain-driven development, extreme programming
- Worked with esteemed customers like ANZ Bank, Old Mutual Group (South Africa), Ford, Farmers Insurance, Aegon Insurance, LaQuinta, Cummins, and AT&T in consulting roles
- Fluent English
$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
Delphi 20yr.
React
Node.js
- Software Engineer with over two decades of experience, specializing in system design, and system integration (System Design, Technical Leadership, System Integration, Scalability, Security, Communication, Documentation);
- Strong abilities with React.js for building, interactive web applications;
- Experienced in Java, Spring Boot, and creating microservices;
- Skilled in Node.js for backend development;
- More than 20+ years of experience with Delphi, Deep knowledge with different versions of Delphi to 10.2;
- Experience with various localisations and Delphi UIs;
- Expert in various programming languages including C++, JavaScript, and Python;
- Experienced in database management with Oracle, MySQL, and PostgreSQL among others (Data Modeling Database Management, Normalization and Denormalization, Data Integrity, Data Warehousing, ETL, SQL and Query Optimization, Database Design, Stored Routines and Packages, Data Backup and Recovery, Data Migration, Web Scraping);
- Experience in technical leadership in various domains such as enterprise software, finance, and healthcare.
Rust 3yr.
Python 1yr.
Solidity
Software engineer with experience in fintech and Web3. Built production-ready applications with cryptocurrency exchange integrations to collect and analyze market data. Familiar with both Ethereum or Solana ecosystems and the best security practices.
Android 6yr.
Kotlin 3yr.
iOS 3yr.
- Mobile developer with 7+ years in Android, iOS, Xamarin, Flutter, and .Net technologies.
- Experienced in backend API and microservices development using ASP .Net Core and Azure.
- Led architectural design and tech support across multi-platform mobile projects.
- Proficient in Kotlin, .Net 6, Xamarin.Forms, and cross-platform frameworks like MvvmCross.
- Strong foundation in computer science with degrees in Information Systems and Multimedia Web Design.
TypeScript 5yr.
Node.js 5yr.
React 5yr.
microservices architecture 5yr.
NestJS 3yr.
- Lead Full-Stack Engineer with 12+ years in distributed systems, AI-driven platforms, and payment ecosystems.
- Expert in event-driven microservices, multi-tenant SaaS, and secure fintech transaction processing.
- Proficient in Typescript, Node.js, React, AWS, Kafka, and AI integrations including LLMs and agentic workflows.
- Architected scalable real-time systems with WebSockets and built AI automation for KYC, risk management, and customer support.
- Strong background in system architecture, prompt engineering, and delivering complex, high-load applications in fintech and iGaming domains.
JavaScript
TypeScript
Python
React
Next.js
- Full-Stack Software Engineer with 7+ years delivering end-to-end web applications using React, Next.js, Vue, NestJS, Django, and FastAPI.
- Expertise in database schema design and optimization with PostgreSQL, MongoDB, MySQL, and Redis.
- Proven experience integrating LLM APIs (OpenAI, Anthropic, LangChain) and building multi-agent AI automation systems reducing manual workload by 70%.
- Skilled in REST API, OAuth 2.0, JWT authentication, RBAC, multi-tenancy, and event-driven architectures.
- Strong background in DevOps with CI/CD, Docker, Kubernetes, AWS, GCP, and automated testing for scalable deployments.
Java 5yr.
Scala 2yr.
- Backend engineer with expertise in Scala, Java (17-21), Python, and cloud-native technologies including Kubernetes, Docker, and AWS.
- Proven track record in end-to-end backend development for B2B SaaS platforms, AI content generation, and e-commerce ecosystems.
- Skilled in system design, API development (gRPC/REST), and integration with external partners and SSO solutions.
- Experienced in microservices architecture, event-driven systems using Kafka and RabbitMQ, and database management with , PostgreSQL, MongoDB, and caching strategies.
- Master’s degree candidate in applied mathematics, with strong foundations in software engineering best practices, code quality, and cross-functional collaboration.
Java 5yr.
Scala 2yr.
- Backend engineer with expertise in Scala, Java (17-21), Python, and cloud-native technologies including Kubernetes, Docker, and AWS.
- Proven track record in end-to-end backend system design, development, deployment, and production support for B2B SaaS and AI-driven projects.
- Skilled in microservices architecture, API design (gRPC/REST), messaging systems (Kafka, RabbitMQ), and database management (PostgreSQL, NoSQL).
- Experienced in CI/CD pipelines, code quality assurance, and cross-functional collaboration to solve complex technical challenges.
- Master’s degree candidate in Applied Mathematics with award-winning problem-solving skills demonstrated by 1st place in Luxoft techground hackathon.
Ruby 5yr.
Ruby on Rails 5yr.
- Over 6 years of experience in software engineering with a strong focus on Ruby and Ruby on Rails, delivering backend solutions in finance, e-government, and construction domains.
- Expertise in building and optimizing GraphQL APIs, asynchronous processing with RabbitMQ, and integrating AWS S3 for file management.
- Proficient in test-driven development using RSpec, improving code quality, reducing technical debt, and maintaining microservices architectures.
- Skilled in PostgreSQL, Redis, RESTful services, and infrastructure collaboration, ensuring high reliability and performance in production environments.
PHP 12yr.
Vue.js 8yr.
Laravel 7yr.
Symfony 4yr.
Full-stack Software Engineer with 12+ years of experience building scalable web applications using PHP, Symfony, Laravel, Vue.js, React, and API Platform. Experienced with PostgreSQL, MySQL, MongoDB, Google Cloud Platform, and Stripe integrations. Skilled in automated testing (PHPUnit, Jest, Cypress), CI/CD, Docker, Kubernetes, and Agile development. Built AI-powered solutions using OpenAI GPT-4o and Microsoft Copilot Studio. Strong expertise in API-first architecture, GraphQL, OpenAPI, and secure authentication with Laravel Passport and Auth0.
Ruby 9yr.
Angular 6yr.
Ruby on Rails 3yr.
- Over 10 years of expertise in Ruby and Ruby on Rails, specializing in scalable web applications, PostgreSQL optimization, and REST/GraphQL API development.
- Proven track record in designing modular microservices architectures and implementing automated KYC systems, enhancing verification success and reducing manual workload.
- Extensive experience with Angular (5+ years) and React for full-stack development, delivering high-traffic social networks and CRM platforms.
- Skilled in performance tuning, reducing API latency by ~30%, and integrating advanced features like face recognition to streamline moderation.
JavaScript 7yr.
React 7yr.
Azure Arm templates 7yr.
- Frontend developer with 7+ years of experience specializing in BigCommerce and e-commerce platforms, proficient in custom app development and Stencil theme customization.
- Expertise in JavaScript, ReactJS, and reusable Web Component widgets, enhancing interactive and scalable frontends.
- Skilled in API integration, responsive design, and Agile Scrum methodologies, ensuring seamless collaboration and efficient development cycles.
- Proficient with Git, BigCommerce Stencil, Shopify Liquid templating, and WooCommerce theme customization, delivering tailored e-commerce solutions.
RESTful API
Backend
React
I'm a Senior Software Developer with 13+ years of experience building scalable web applications for international remote teams. My primary stack includes React, Node.js, Python, PostgreSQL, and cloud platforms such as Google Cloud and AWS. Recently, I've been developing AI-powered web applications and automation workflows while collaborating with distributed teams across the US, Singapore, and Europe. I enjoy creating clean, maintainable solutions, continuously learning new technologies, and contributing to products that deliver real business value.
Java
microservices
TypeScript
Spring Boot
Node.js
Led backend teams and delivery for critical Java services; designed and evolved scalable APIs and microservices; improved production reliability through observability, testing and CI/CD; mentored developers; delivered integrations and payment-related systems; built and operated modern serverless product infrastructure using TypeScript, PostgreSQL and cloud services.
Java 3yr.
Spring Boot 3yr.
FDD 3yr.
- Backend Developer with 3+ years in enterprise AdTech, specializing in publisher onboarding, campaign management, and automation for platforms handling $1M+ ad spends.
- Proficient in Java, Spring Boot, microservices, REST APIs, and asynchronous integration flows across multiple ad channels including Reddit, LinkedIn, Apple Search Ads, and Snapchat.
- Skilled in designing and implementing scalable backend features, handling complex API integrations, rate limits, entity mapping, and timezone offsets.
- Experienced in AWS, Kafka, Kubernetes, Docker, Jenkins and GitHub Actions.
- Strong testing and monitoring expertise with unit, E2E, API tests, Datadog metrics, dashboards, and alerts.
Python 14yr.
TypeScript 14yr.
PHP 12yr.
React 10yr.
React Native 9yr.
- 14+ years architecting and deploying scalable AI chatbots and multi-tenant web platforms, automating 80%+ client support inquiries and supporting 10M+ monthly users.
- Expertise in Python, PHP, JavaScript/TypeScript, with advanced use of frameworks like Django, FastAPI, Laravel, React.js, and React Native for full-stack development.
- Proficient in AI tools including Rasa, Dialogflow, LangChain, OpenAI APIs, and vector databases, delivering HIPAA-compliant healthcare and fintech solutions.
React 7yr.
Node.js 7yr.
NestJS 7yr.
TypeScript 7yr.
JavaScript 7yr.
- Software engineer with 7+ years of experience specializing in MERN stack, PHP, and modern JavaScript frameworks including React.js, Node.js, and Nest.js.
- Proficient in TypeScript, Laravel, CodeIgniter, MongoDB, and MySQL, delivering scalable web applications following best SDLC practices.
- Strong foundation in computer science with a B.Tech degree, applying engineering principles to develop robust backend and frontend solutions.
- Experienced in agile methodologies and software design patterns, contributing to projects at RipenApps
- Demonstrated ability to integrate complex systems and optimize performance in diverse domains, ensuring maintainability and code quality.
Python 6yr.
TypeScript 4yr.
Node.js 4yr.
React 4yr.
AI-agents 2yr.
- Senior Full-Stack Engineer with 10+ years designing and deploying scalable SaaS platforms and agentic AI systems using Python, TypeScript, Node.js, and React.
- Expertise in building multi-step autonomous workflows, tool-calling agents, RAG pipelines, and LLM evaluation harnesses leveraging LangChain, OpenAI, Claude APIs, and vector search technologies.
- Holds a Bachelor of Computer Science degree, with extensive experience in software development lifecycle, prompt engineering, agent orchestration, and advanced AI-driven enterprise solutions.
Web Development
Front-End Web Development
Backend
Designed and delivered scalable web and mobile applications using React, Next.js, Node.js, Flutter, and Supabase. Built secure APIs, AI-powered solutions, authentication systems, payment integrations, and responsive user interfaces. Improved application performance, optimized databases, automated workflows, and successfully delivered multiple full-stack projects while collaborating with cross-functional teams to create reliable, user-focused software that met business goals and enhanced customer experiences.
SQL 5yr.
Go 4yr.
Docker 3yr.
Git
RESTful API
- Backend developer with 4+ years of experience specializing in Golang, SQL, Docker, and cloud-native solutions on AWS and GCP.
- Proven expertise in designing and implementing scalable backend services, SDKs, and cross-cloud integrations with database-level synchronization (pglogical).
- Strong background in blockchain technologies, microservices, and smart contract development using Solidity, Rust, and Typescript.
- Skilled in observability tools (Prometheus, Grafana), authentication mechanisms (JWT, 2FA).
- Holds Bachelor's and Master's degrees in Cybersecurity, combining solid computer science education with practical software development and DevOps practices.
AI Agents: n8n 2yr.
Workflow Management 2yr.
CRM 2yr.
Designed and implemented AI solutions including custom AI agents, Retrieval-Augmented Generation (RAG) applications, and OpenAI integrations. Delivered automation workflows that reduced manual effort, improved customer engagement, and streamlined business operations through scalable, production-ready AI systems.
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.
React 5yr.
Node.js 5yr.
TypeScript 5yr.
Vue.js 4yr.
Express 4yr.
- Full-stack developer with 5+ years of experience delivering scalable web applications using Vue.js, React, Next.js, Node.js, and Express.js, Nest.js.
- Proficient in TypeScript, Vue 3 Composition API, RESTful API design, and backend microservices architecture.
- Skilled in modern frontend frameworks, Material Design libraries, and responsive UI development with strong emphasis on reusable components and performance optimization.
- Experienced in integrating AI-assisted coding tools (Claude Code, Cursor) to enhance development efficiency and code quality.
- Solid expertise in software development lifecycle, Git, CI/CD, and cloud platforms (AWS, GCP, DigitalOcean).
React Native 2yr.
JavaScript 2yr.
TypeScript 2yr.
Node.js 2yr.
Express JS API (NodeJS) 2yr.
Main Achievements:
- Built scalable full-stack web applications using modern frameworks and DevOps practices for seamless deployment.
- Developed cross-platform mobile apps with React Native, delivering high-performance user experiences.
- Automated CI/CD pipelines to improve deployment efficiency and reduce manual errors.
- Created responsive front-end solutions that enhance user engagement and site performance.
- Earned certifications in React and DevOps to stay updated with industry best practices.
website
Website optimizations
Sales Landing Page
Web Development
Front-End Web Development
Designed and optimized modern websites and sales landing pages that improve user experience, mobile responsiveness, and business conversions. Delivered responsive front-end solutions, enhanced website performance, and implemented SEO best practices to help businesses strengthen their online presence. Experienced in web development, website optimization, and creating scalable websites that meet both client and user needs.
React 9yr.
Blockchain 2yr.
Spring Boot
Gemini 3
OpenAI
I am a senior software architect and blockchain automation engineer , with over 20 years of professional development experience and 4+ years dedicated to crypto, trading bots, WebSocket systems, and SaaS automation platforms.
My career spans enterprise systems, mobile applications, cloud analytics, authentication infrastructure, and large-scale data platforms — evolving into high-performance blockchain automation and bot engineering across Solana and Ethereum ecosystems.
I specialize in building:
- Real-time token tracking systems
- Telegram trading bots
- Solana Token Bundling, Deployment and tracking platforms,
- Rug detection & dev-sell intelligence
- MongoDB-driven analytics platforms
- Event-driven SaaS backends
All systems are designed for 24/7 uptime, restart persistence, and real trader usage — not prototypes.
Core Expertise
Blockchain & Crypto
- Solana Web3.js
- Ethereum (EVM)
- Pump.fun SDK
- Token metadata indexing
- Market cap & liquidity tracking
- Dev-sell detection
- Rugpull analysis
- ATH / ROI analytics
- Wallet behavior monitoring
Bot & Automation Systems
- Trading bots
- Token sniper trackers
- Telegram bots
- Volume simulation bots
- Alert engines
- Subscription lifecycle managers
Real-time ranking systems