Hire Vetted Web Application Engineers at Upstaff - Page 7
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
Java 9yr.
Go 6yr.
Spring Boot 6yr.
- Senior Software Engineer with 9+ years in fintech and banking, specializing in Golang, Java, Kotlin, and Python for scalable, cloud-native microservices architectures.
- Proven expertise in AWS (Lambda, S3, CloudFormation), event-driven systems (Kafka, RabbitMQ, Debezium CDC), and CI/CD pipelines with Blue/Green deployments ensuring zero-downtime releases.
- Led multiple engineering teams delivering complex financial platforms including digital lending, credit line, factoring, and trade finance with integrations to banking and government APIs.
- Strong background in software design patterns, RESTful and RPC APIs, automated testing (Cucumber, Spock), and observability tools (Grafana, ElasticSearch, CloudWatch).
- Holds a Computer Science degree and Information Systems management education, combining deep technical skills with leadership in Agile environments and extensive interviewing experience.
React
Node.js
TypeScript
- Senior Full Stack Engineer with 7+ years of expertise in React, Next.js, TypeScript, Node.js, NestJS, and PostgreSQL.
- Experience in Gambling, SaaS, Fintech, and consumer applications, including high-load systems, real-time features, and third-party integrations.
- Expertise in cloud infrastructure and DevOps with AWS, GCP, Azure, Docker, Kubernetes, and CI/CD pipelines.
- Backend skills, including REST API, GraphQL, Strapi CMS, serverless Firebase Cloud Functions, and database design with PostgreSQL, MongoDB, and Cosmos DB.
- Worked with different architectural approaches, including micro-frontends, BFF (backend-for-frontend) layers, and serverless solutions.
Java 10yr.
Spring Boot 5yr.
RESTful API 5yr.
microservices 3yr.
AWS 3yr.
- Senior Java Backend Engineer with 10+ years of experience delivering high-throughput, production-grade systems in healthcare and fintech domains.
- Expertise in Java (8 to 22), Spring Boot (2.7 to 3.5), microservices, Hexagonal and Clean Architecture, and SOLID principles ensuring scalable and maintainable codebases.
- Proven track record in architecting backend services, optimizing PostgreSQL performance, and integrating AWS cloud services including S3 and ECS.
- Hands-on experience with real-time big data pipelines processing 20+ TB/day using Kafka, Spark, Hadoop, and Cassandra.
- Strong foundation in computer science with M.Sc. degree and extensive knowledge of RESTful API design, CI/CD pipelines, and test-driven development using JUnit, Mockito, and Jacoco.
Kotlin 4yr.
Spring Boot 4yr.
Azure DevOps 2yr.
Docker 2yr.
- 9+ years of experience in Java and Kotlin software engineering, specializing in microservices architecture, DevOps, and cloud-native applications.
- Proficient in Spring Boot, Spring Cloud, Docker, Kubernetes, AWS, and CI/CD pipelines, with hands-on experience in Terraform and Jenkins for infrastructure automation.
- Strong background in secure software development, including Keycloak integration, OAuth2, and PCI DSS-compliant cryptographic SDKs.
- Expertise in designing and implementing scalable backend systems using Kafka, RabbitMQ, Elasticsearch, and various databases like PostgreSQL, OracleDB, MongoDB, and Cassandra.
- Experienced in Agile methodologies (Scrum, Kanban), test-driven development (JUnit, Mockito, Testcontainers), and modern software engineering best practices.
C/C++/C# 5yr.
Robot Framework 5yr.
.NET Core 5yr.
ASP.NET Core Framework 5yr.
ASP.NET MVC
Senior .NET Developer with over a decade of professional experience, showcasing advanced competencies in scalable and secure web application development, microservices architecture, and cloud solutions. Expertise in crafting optimized code by leveraging C#, ASP.NET Core, Entity Framework, and diverse databases like MS SQL Server and MongoDB. Proven track record in improving system performance, maintainability, and accelerating development cycles through SOLID principles and modern DevOps practices. Demonstrated ability touring in enterprise-level API development, and security enhancements, further leveraging CI/CD, containerization, and serverless technologies in both Microsoft Azure and AWS environments. Adept in applying design patterns and software engineering principles like CQRS, DDD, and the Akka.NET actor model to build robust and fault-tolerant systems.
HTML
CSS
Ruby
Java
- Proficient in front-end and back-end development with expertise in HTML, CSS, Ruby, Java, and Vim, complemented by 3+ years of hands-on experience in software engineering.
- Currently engaged in networking projects, applying practical knowledge of system integration and network protocols to enhance infrastructure reliability.
- Strong foundation in Information Technology from Karatina University, emphasizing software development lifecycle (SDLC) and modern programming paradigms.
- Skilled in using Blender for 3D modeling, demonstrating versatility in both software development and digital content creation.
- Fluent in English and Kiswahili, facilitating effective communication in diverse team environments and cross-functional collaborations.
HTML
CSS
Ruby
Java
- Proficient in front-end and back-end development with expertise in HTML, CSS, Ruby, Java, and Vim, complemented by 4+ years of academic and practical experience in Information Technology.
- Currently engaged in networking projects, applying software development lifecycle (SDLC) principles to deliver scalable and maintainable solutions.
- Strong foundation in software engineering methodologies, with hands-on experience in programming paradigms and tools including Blender for technical visualization.
- Academic background from Karatina University, specializing in Information Technology, ensuring a solid understanding of computer science fundamentals and engineering principles.
- Demonstrated ability to integrate diverse technologies and tools to optimize system performance and user experience in real-world applications.
Python 7yr.
Django REST framework 2yr.
Flask 2yr.
FastAPI
Celery
- Senior Backend & AI Engineer with 7+ years designing scalable, low-latency distributed systems and GenAI platforms in YC-backed and enterprise environments.
- Expert in Python, FastAPI, Django/DRF, and event-driven microservices, specializing in resilient, self-scaling cloud-native backends using AWS, GCP, and Kubernetes.
- Proficient in Agentic RAG pipelines, LangChain, LLM inference (Ollama/VLLM), vector databases, and real-time data pipelines for fintech and AI-driven applications.
- Led teams and architected high-throughput data systems ensuring 99.9% uptime during transaction spikes and optimized database performance with PostgreSQL, MongoDB, and advanced ORM techniques.
- Holds MCA and PGDCA degrees with a strong foundation in computer science, delivering end-to-end solutions across SDLC, CI/CD, Terraform, and security audits for global clients.
Angular 4yr.
TypeScript 4yr.
JavaScript 4yr.
- Software Engineer with 4+ years of experience specializing in Angular (v7-v18), NgRx, SolidJS, and TypeScript for high-performance web applications.
- Proficient in designing and implementing CI/CD pipelines, automated workflows using Azure DevOps, and integrating analytics tools like Power BI and Amplitude for data-driven insights.
- Strong background in computer engineering with hands-on expertise in secure payment platforms, cloud-based solutions, and system automation using Ansible and Debian packaging.
- Demonstrated ability to optimize application performance, reduce load times by 30%, and enhance modularity and testing coverage with Jasmine and Cypress.
- Contributor to open source security improvements and recognized for technical excellence with an Employee of the Quarter award.
JavaScript 4yr.
React 4yr.
Node.js 4yr.
TypeScript 4yr.
React Native 2yr.
- Full-stack developer with 4+ years of experience specializing in JavaScript, TypeScript, React, Next.js, Node.js, and PostgreSQL, delivering scalable, production-grade web applications.
- Proficient in modern software architecture, microservices, event-driven systems, and cloud infrastructure using AWS (Lambda, RDS, API Gateway, Cognito, S3).
- Led backend teams to implement subscription management features in a sports streaming platform using Node.js, Docker, Terraform, and CI/CD pipelines.
- Expertise in state management (Redux, MobX, Zustand), real-time communication (WebSocket, WebRTC), and UI/UX design with pixel-perfect responsive interfaces.
- Strong background in Agile methodologies, code quality assurance through unit/integration testing, and collaborative development workflows with Git, GitHub, and GitLab.
React 8yr.
TypeScript 8yr.
Python 8yr.
Ext JS 5yr.
- Senior Full-Stack Engineer with 10+ years of experience delivering enterprise-grade web applications using React, Next.js, TypeScript, Python, and cloud-native technologies.
- Expertise in designing and integrating REST APIs, backend services with Django REST Framework and FastAPI, and optimizing frontend performance with reusable components and advanced state management.
- Proficient in containerization and orchestration using Docker and Kubernetes, with hands-on experience in AWS-hosted CI/CD pipelines and GitHub Actions for stable, efficient releases.
- Strong background in agile software development, technical documentation, and client collaboration to translate complex business requirements into scalable technical solutions.
- Holds a Bachelor of Computer Science degree and completed advanced training in React, Redux, and Python design patterns, ensuring up-to-date engineering practices and design principles.
Ruby
Ruby on Rails
- 15+ years of professional experience in software engineering, including 10+ years specializing in Ruby on Rails.
- Skilled in Ruby, Ruby on Rails, JavaScript/TypeScript, React JS, Angular JS, and RESTful API design, cloud platforms (AWS, Azure, GCP) and containerization (Docker, Vagrant).
- Experience in software architecture, design patterns, UML, MVC, TDD, BDD, and Agile methodologies (Scrum, Kanban, XP), SDLC.
- Leadership in large-scale projects including telemedicine, legal services, and e-commerce platforms, driving architecture, team coaching, and performance optimization (Elasticsearch, Sidekiq), and advanced database technologies (MySQL, PostgreSQL, MongoDB).
- Skilled in memory optimization, big data processing, API integration, code refactoring, and comprehensive documentation, delivering scalable and maintainable solutions across diverse domains.
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.
Ruby
Ruby on Rails
SQL
MongoDB
PostgreSQL
- 12+ years of professional experience specializing in Ruby on Rails development, DevOps engineering, and team leadership.
- Skilled in Ruby, Rails, SQL, MongoDB, Terraform, Docker, AWS, and Hetzner.
- Ability to optimize backend logic, database queries, and application performance, including resolving complex memory leaks and enhancing system reliability.
- Skilled in integrating frontend technologies such as ReactJS and CoffeeScript, and implementing CI/CD pipelines, infrastructure as code, and containerization.
- Experienced in leading teams, coordinating workloads, mentoring developers, and managing client requirements to deliver high-quality software solutions.
PHP 4yr.
MySQL 4yr.
Redis 4yr.
Laravel 2yr.
- Software engineer with 4+ years of experience specializing in backend development using PHP, Laravel, Phalcon, and Symfony, delivering optimized web applications and scalable APIs.
- Proficient in database design and management with MySQL, Redis, and Elasticsearch, alongside expertise in queue processing and performance optimization.
- Skilled in cloud infrastructure and DevOps tools including Docker, AWS (EC2, S3, CloudWatch), Azure, Nginx, Linux, and CI/CD pipelines to ensure robust deployment workflows.
- Strong foundation in computer science with a Bachelor's degree, covering algorithms, data structures, design patterns, OOP, SOLID principles, and multiple programming paradigms.
- Experience mentoring developers and integrating complex APIs, with additional knowledge in C++, JavaScript, and machine learning concepts, contributing to diverse project success.
$32/hr
.NET Core
ASP.NET Core Framework
Azure
- Software Engineer with 5+ years of experience in .NET Core, C#, ASP.NET Core, and TypeScript.
- Experienced in cloud and integration development (Azure Functions, Logic Apps), and AWS, with a focus on event-driven and distributed systems (RabbitMQ, Redis, Hangfire).
- Skilled in designing integration workflows, data transformation pipelines, and solutions aligned with iPaaS and ETL principles.
- Experience in modernizing legacy systems and migrating to cloud-native, microservices, and API-led architectures.
- Skilled in REST, gRPC, and database design (PostgreSQL, MSSQL, MongoDB), along with CI/CD and testing.
TypeScript
Node.js
React
- Senior Full Stack Engineer with 5+ years of experience developing web and mobile applications;
- Implemented APIs and microservices with Node.js, Nest.js, PostgreSQL, including caching, queue management, and AWS infrastructure (Proxet, NovaPay, and Web3 Startup);
- Built interfaces and component libraries using React, Vue, React Native, Next.js, TypeScript, and JavaScript (Proxet (SSR web platform), NovaPay (mobile app), and Web3 Dashboard);
- Experienced in fintech, Web3, and enterprise platforms, delivering production features, maintaining existing systems, and working in Agile teams.
Python 9yr.
JavaScript 8yr.
Django REST framework 6yr.
Flask 6yr.
AngularJS 6yr.
- Over 11 years of experience in backend and full-stack development with expertise in Python (Django, Flask, FastAPI) and JavaScript frameworks (Angular, Vue.js, React).
- Proficient in designing scalable microservices and monolithic architectures, optimizing API performance (e.g., reducing heavy request times from minutes to under 1 second).
- Strong skills in DevOps and cloud infrastructure including AWS, Docker, Jenkins CI/CD, and infrastructure automation with Ansible.
- Hands-on experience with databases (PostgreSQL, MySQL, ClickHouse, Neo4j), caching, messaging systems (Kafka, Redis), and search technologies (Elasticsearch, Solr).
- Computer Science education with a Bachelor’s degree in Automated Systems of Information Processing; led teams and delivered complex features improving system responsiveness and client satisfaction.
C/C++/C#
Java
Kotlin
PHP
- Undergraduate in BSc Software Engineering at Cardiff Metropolitan University with hands-on experience in full stack web and API development.
- Proficient in C#, Java, PHP, ASP.NET Core, Entity Framework Core, React, and mobile development using Java/Kotlin and Android Studio.
- Developed multiple real-world projects including e-commerce platforms, veterinary management systems, and freelance service marketplaces using SQL Server, MySQL, and SQLite databases.
- Skilled in building responsive, user-friendly web applications and backend APIs following modern software development practices and version control with Git.
- Experience in end-to-end software development lifecycle, from requirement analysis to deployment, demonstrated through academic and freelance projects.
Python 6yr.
Django REST framework 2yr.
Flask 2yr.
JavaScript
FastAPI
- Senior Backend Engineer with 7+ years of expertise in designing and deploying scalable, secure backend systems and AI-powered platforms using Python, Django, Flask, and FastAPI.
- Proficient in integrating databases (MySQL, PostgreSQL, MongoDB) with ORM tools like Django ORM and SQLAlchemy, and experienced in cloud-native architectures across AWS, Azure, and GCP.
- Hands-on experience in AI/ML, LLM inference, Agentic RAG pipelines, and productionizing intelligent systems for real-time, high-traffic consumer applications.
- Strong engineering background with a Master’s in Computer Application and top academic performance, complemented by leadership roles mentoring development teams and managing end-to-end project delivery.
- Skilled in distributed systems, API development, automation, cybersecurity best practices, and modern software development methodologies ensuring system stability and performance.
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).
JavaScript 5yr.
TypeScript 5yr.
Node.js 5yr.
Go 3yr.
NestJS 1yr.
- Software engineer with 7+ years of experience specializing in full-stack development using JavaScript/TypeScript, C#, Go, and Python across macOS, Unix, and Linux environments.
- Proven expertise in architecting scalable microservices, event-driven systems, and cloud-native applications leveraging AWS, Azure, GCP, Kubernetes, Docker, and CI/CD pipelines.
- Strong background in designing and optimizing databases (PostgreSQL, MongoDB, Cassandra, Neo4j) and implementing high-performance caching and real-time data streaming solutions with Kafka and Redis.
- Skilled in modern frameworks and tools including Node.js, Nest.js, React, Django, and Spring, with hands-on experience in OAuth 2.0, JWT security, and compliance with ISO 27001 and GDPR.
- Computer Science degree with demonstrated success in improving system performance by up to 40%, automating workflows, and leading migrations from monolithic to microservices architectures.
React 2yr.
Facebook Auth 1yr.
Java 1yr.
- Front-End Developer with expertise in React.js and Flutter, delivering responsive, high-performance web and cross-platform mobile applications.
- Proficient in translating UI/UX designs into scalable, pixel-perfect interfaces, with strong skills in component-based architecture and performance optimization.
- Experience in Agile methodologies, collaborating with cross-functional teams to deploy digital solutions and enhance user engagement.
- Background in Agricultural & Bio-environmental Engineering with additional certifications in Business Strategy, CRM, HR, and Project Management.
- Hands-on knowledge of blockchain technology and decentralized platforms, complemented by full-stack development experience using Java and Asp.Net.
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.
Ruby 13yr.
Ruby on Rails 13yr.
- Experienced full-stack web developer and team lead with a solid knowledge of strategies, patterns, and technologies.
- Proven experience and expertise in building and maintaining full-stack applications, adept at both backend and frontend development using technologies such as Ruby on Rails, Elixir, Phoenix, JavaScript, React.js, and Go.
- Proficient in configuring cloud architectures using AWS CDK scripts and deploying applications to cloud services such as AWS and GCP
- Extensive background in backend API development, including building messaging platforms, digital contracts signing platforms, and social network MVPs using technologies like Elixir, Phoenix, and GraphQL API.
- Strong database architecting and management expertise, with hands-on experience in PostgreSQL, Redis, and other database technologies, contributing to efficient data storage and retrieval.
- Demonstrated leadership as a CTO, leading teams, setting strategic goals, managing team dynamics
- Upper-Intermediate English
Java
- Full-Stack Developer with experience in various projects, including military weapon maintenance, truck analytics, app store launch, social benefits management, ISP monitoring, and router web interface.
- Over 6 years of experience and a solid background in object-oriented analysis and design, comprehensive knowledge of system development life cycle, physical and logical data modeling, performance tuning, and enterprise-level system development.
- Led a team responsible for data migration to the cloud, enabling server-to-cloud data synchronization and strengthening software security.
- Upper-Intermediate English
Ruby on Rails
PostgreSQL
React
Elasticsearch
Angular
14 years of professional expertise in IT industry;
12+ years using Ruby on Rails framework and Rails ecosystem;
4+ years using JavaScript; (Angular JS, React JS, Backbone Js, Vue Js, Vanila Js)
Rich experience in Web development using JQuery, CSS, HTML,
Bootstrap, 3 less);
Experience in databases: PostgreSQL, Mongo DB;
Agile CRM
Java
API
TypeScript
Angular
JavaFX
An adept Full Stack Software Developer with over 14 years of comprehensive experience in IT, specializing in Java and Continuous Integration/Continuous Delivery (CI/CD) practices. Technically proficient in developing RESTful APIs, tailoring frontend libraries with Angular and TypeScript, and securing applications with Spring Security. Proven history of leveraging agile methodologies to advance software development life cycle (SDLC) processes in international projects, focusing on industries like gaming and traffic control. Passionate about knowledge sharing, evidenced by contribution to a Java newsletter and mentoring roles. This engineer's history showcases a solid foundation in electrical engineering technologies and a consistent drive for enhancing software manufacturing through innovation and rigorous quality assurance.
$25/hr
$4500/month
$4500/month
Ruby
JavaScript
7+ years of web development experience, during last 4 years I have been dedicated to RoR.
React
Node.js
- 5+ years of professional experience using front-end and back-end technologies
- Solid experience in building rich web applications (monolith and MSA) using frameworks and libraries such as React, NestJs, Express
- Most of the development experience was gained in projects related to business corporate networks, coaching
platforms, insurance, fintech, leasing, and event-management systems
- Front-end: JavaScript(ES6), React, Redux, Next.js, Redux-saga, Context API, React Hooks, Chartjs, HTML, CSS(SCSS), MaterialUI, AntDesign, Tensorflow
- Back-end: NodeJS (Express, NestJS), REST API, Docker, Terraform
- Upper-Intermediate English
Laravel
- Sauvik Kundu is a Senior Software Engineer with 6+ years of experience in backend development.
- He has expertise in PHP, Laravel, MySQL, and Web Services API.
- Sauvik has worked on projects related to Management, SaaS-based, CRM, ERP, E-commerce, and Chat apps.
- He has experience in optimizing project queries and integrating various APIs and tools.
- Sauvik has a strong understanding of Agile methodologies and Test Driven Development.
- He has a Master's degree in Computer Science and Engineering from BRAC University.
- Sauvik is passionate about product growth and user-centric design, and aims to work in dynamic, product-focused companies.
React Native
- Senior Software Engineer with 6 years of experience in the IT industry, 5+ of them at cross-platform mobile development.
- Mostly works with React and React Native.
- He does his best to keep up with modern practices and modern technologies, that way he can offer clients the most up to date solutions that give the users of their application the best experience.
- Team player and flexible in the working environment.
- Responsible Engineer willing to grow professionally and create new effective solutions for business.
- Upper-Intermediate English.