Hire the Best Sinatra Framework Developers

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Zehao J.

Qingdao, China

$25/hr
5.0
7 jobs

โœ… 6+ Years of Java Development Experience โšก Full-Cycle Backend Development & Architecture โšก AI-Powered Development for Faster Delivery & Better Code Quality ๐Ÿ‘€ Click Invite or Hire for Scalable Java Backend Solutions Looking for a Java Developer who can build scalable backend systems, SaaS platforms, enterprise applications, and cloud-native solutions designed for long-term growth? For 6+ years, I have hands-on experience taking multiple backend systems from zero to production โ€” covering API design, database modeling, AI/LLM integration, payment systems, and server deployment end-to-end. My primary stack is Java and Spring Boot, with a strong focus on building systems that are clean, maintainable, and ready to scale. What I can do for you: ๐๐š๐œ๐ค๐ž๐ง๐ ๐€๐๐ˆ ๐ƒ๐ž๐ฏ๐ž๐ฅ๐จ๐ฉ๐ฆ๐ž๐ง๐ญ | Java ยท Spring Boot ยท Spring MVC ยท Spring Security ยท JWT ยท Design and build RESTful APIs from scratch ยท Implement authentication & authorization (JWT, Spring Security, role-based access control) ยท Structure business logic that is clean, testable, and maintainable ๐€๐ˆ & ๐‹๐‹๐Œ ๐ˆ๐ง๐ญ๐ž๐ ๐ซ๐š๐ญ๐ข๐จ๐ง | Claude API ยท OpenAI ยท Prompt Engineering ยท Integrate Claude or OpenAI into real product workflows โ€” not just demos ยท Build multi-turn dialogue flows and connect model outputs to backend logic ยท AI-powered automation pipelines and event-driven AI workflows ๐ƒ๐š๐ญ๐š๐›๐š๐ฌ๐ž ๐ƒ๐ž๐ฌ๐ข๐ ๐ง & ๐Œ๐š๐ง๐š๐ ๐ž๐ฆ๐ž๐ง๐ญ | PostgreSQL ยท MySQL ยท Redis ยท Spring Data JPA ยท Qdrant ยท Design schemas and data models from scratch ยท Write complex queries and handle migrations ยท Performance optimization and caching with Redis ยท Vector database setup and operations โ€” storing embeddings, similarity search, and retrieval pipelines (Qdrant) ๐๐š๐ฒ๐ฆ๐ž๐ง๐ญ & ๐’๐ฎ๐›๐ฌ๐œ๐ซ๐ข๐ฉ๐ญ๐ข๐จ๐ง ๐’๐ฒ๐ฌ๐ญ๐ž๐ฆ๐ฌ | Stripe Connect ยท Webhook ยท Integrate Stripe โ€” subscription tiers, billing cycles, webhook event handling ยท Build payout logic and third-party payment flows ๐’๐ž๐ซ๐ฏ๐ž๐ซ ๐ƒ๐ž๐ฉ๐ฅ๐จ๐ฒ๐ฆ๐ž๐ง๐ญ & ๐ƒ๐ž๐ฏ๐Ž๐ฉ๐ฌ | DigitalOcean ยท Docker ยท Nginx ยท CI/CD ยท Linux ยท Set up and manage production environments ยท Docker containerization, Nginx reverse proxy, SSL, CI/CD pipelines ๐“๐ก๐ข๐ซ๐-๐ฉ๐š๐ซ๐ญ๐ฒ & ๐–๐ž๐›๐ก๐จ๐จ๐ค ๐ˆ๐ง๐ญ๐ž๐ ๐ซ๐š๐ญ๐ข๐จ๐ง | FCM ยท APNs ยท OAuth ยท REST ยท Connect backend to external services via REST APIs or webhooks ยท Push notifications (FCM / APNs), OAuth, event-driven automation ๐…๐ซ๐จ๐ง๐ญ๐ž๐ง๐ ๐‚๐จ๐ฅ๐ฅ๐š๐›๐จ๐ซ๐š๐ญ๐ข๐จ๐ง | Vue3 ยท Nuxt.js ยท TypeScript ยท Tailwind CSS ยท Work alongside frontend teams or handle supporting frontend work independently ยท Define API contracts, handle CORS, integrate backend services end-to-end I communicate clearly, deliver on schedule, and am comfortable working independently from requirements through to deployment. Feel free to reach out with your project.

  • Spring Boot
  • Java
  • Spring Framework
  • Spring Data
  • Auth0
  • Rust
  • MyBatis
  • Database
  • PostgreSQL
  • MySQL
  • Thymeleaf
  • JavaScript
  • React
  • Nuxt.js
  • Vue.js
Rida B.

Casablanca, Morocco

$220/hr
5.0
54 jobs

With 20 years of experience across industries like logistics, finance, education, e-commerce, and telco, I bring deep technical expertise and leadership to every project. My career spans roles at global companies like Nespresso and multiple CTO positions in startups, where Iโ€™ve architected and scaled systems from MVP to production. As an UpWork Expert-Vetted freelancer (Top 1%), Iโ€™ve helped clients worldwide design, build, and optimize complex platforms โ€” from mission-critical enterprise systems to lean MVPs. Clients trust me to step in at any stage: rescue high-stakes projects, design scalable architectures, or lead end-to-end product delivery. ๐Ÿ’ก Selected Highlights - CTO, MarocSchoolBus.com โ€“ Built a real-time school bus tracking system with React, TypeScript, and AWS serverless, used by schools, drivers, and parents. - Technical Lead, ScienceBank.com (Harvard-affiliated) โ€“ Guided the architecture and delivery of a scientific peer review platform on AWS serverless and React. - Principal Engineer, LittleVista.ie โ€“ Managing full-stack development and DevOps for a childcare SaaS platform. - Enterprise Projects โ€“ Led Java migrations and system integrations for Nespresso, Ericsson, and other major organizations. ๐Ÿ”ง Technical Expertise Cloud & DevOps - AWS Certified (Solutions Architect, Developer, SysOps) - Serverless, Microservices, CI/CD pipelines, Infrastructure as Code Backend Architecture - Java (Oracle Master Certified Java EE Architect) - Node.js, REST APIs, event-driven systems, blockchain integration Frontend Engineering - ReactJS, Angular, TypeScript, Next.js, SPA development Startup Enablement - MVP design & execution - CTO-as-a-Service - Architecture consulting & scaling strategies ๐ŸŽฏ Whether you need a scalable architecture from scratch, an MVP to validate your vision, or expert guidance to optimize an existing system, I deliver solutions that are robust, future-proof, and tailored to your business goals.

  • Java
  • Amazon Web Services
  • Microservice
  • Git
  • JavaScript
  • Angular
  • React
  • SQL
  • Web Development
  • DevOps
  • Google Cloud Platform
  • Unix Shell
  • API
  • Serverless Computing
Vipul T.

Gurgaon, India

$25/hr
5.0
19 jobs

Hello, Thank you for checking out my profile, I'm an independent freelancer working in software dev for more than a decade now. Below is a quick overview of my core strengths as a solution developer and technical architect. Technical Overview: โ€ข Coded expense manager, flight data service, Battleship games, Bidding system, weather monitoring service, etc for multiple users. โ€ข The expert mode in REST API's development using Spring Boot 3/Spring Cloud Streams, Spring Security, and Spring Gateway along with microservice architecture. โ€ข In Databases, for RDBMS (Postgres, Mysql, Clickhouse), NoSQL (AWS Dynamo, MongoDB, Redis), and Elastic Search. โ€ข Extensively worked in AWS techs like SQS, SNS, Fargate (ECS), and MSK (Kafka). โ€ข Dockerized microservices and created CI CD pipeline for service deployment . โ€ข Have designed multiple complex systems from zero to full-fledged deployment in production. โ€ข A problem solver for any complex system with minimal guidance. You can count on me. How can I help you: โ€ข Have worked in multiple domains like banking, financial, telecom, gaming, travel, supply chain, etc so can help with any type of project. โ€ข Designed complex architecture in the past so can help in technical architecture space for pros and trade-offs of the current system. โ€ข Consult for any software development that needs data management or a high level of concurrency or even if you are stuck at an unknown place during development. Thanks. Looking forward to working with you. On Upwork have worked on Google API, AWS, Websocket, Otel, MongoDB, Postgres and Elastic search.

  • API Development
  • MongoDB
  • RESTful API
  • Spring Framework
  • Database Programming
  • Docker
  • Apache Kafka
  • Spring Boot
  • Redis
  • Kubernetes
  • Amazon Web Services
  • MySQL Programming
  • Java
  • Elasticsearch
  • Oracle Database
Umar F.

Lahore, Pakistan

$25/hr
5.0
2 jobs

Full Stack Developer | Senior Ruby on Rails Engineer | AI Integrations, RAG & MCP | SaaS Need a Full Stack Developer who can turn a Rails codebase โ€” or a fresh idea โ€” into something that actually runs in production? You're in the right place. I'm a Senior Ruby on Rails developer with 6+ years of experience building and scaling SaaS products across PropTech, healthcare, and e-commerce. More recently I've focused on integrating AI into production systems: RAG search, LLM-powered workflows, and MCP servers that let AI agents interact safely with live applications. Specialization & Focus I specialize in Ruby on Rails, Python, Node.js, React, and Next.js, helping teams: - Ship AI features that run in production, not just demos - Build and scale multi-tenant SaaS platforms - Modernize legacy Rails codebases without breaking what already works - Integrate third-party APIs, CRMs, and payment systems reliably - Automate backend workflows with background jobs and queues What I Build SaaS & Backend Systems - Rails APIs and backend architecture for multi-tenant SaaS platforms - PostgreSQL schema design, query optimization, and data modeling - Sidekiq background jobs, queues, and asynchronous processing - React and Next.js frontends on top of Rails APIs AI & Automation - RAG pipelines using pgvector for retrieval-augmented generation - MCP server development so AI agents can safely query live systems - OpenAI API integrations โ€” embeddings, workflow automation, AI-powered features - AI-assisted development using Claude Code for faster, cleaner delivery Integrations & Payments - Stripe billing โ€” subscription lifecycles, webhooks, invoicing - CRM and third-party API integrations โ€” GoHighLevel, Google Places, Google Calendar - REST API design and third-party service integration Cloud & Production - AWS and Docker deployments - Redis for caching and job queues - Performance tuning and legacy system modernization Industries I Work With - PropTech & Real Estate โ€” property management SaaS, compliance platforms, rental scheduling - Healthcare โ€” patient management, subscription billing, sensitive data handling - E-commerce & ERP โ€” Stripe-powered billing, customer portals - SaaS & B2B Platforms โ€” multi-tenant architecture, workflow automation Technical Background - Backend: Ruby on Rails, Python, Node.js, Sidekiq, REST APIs - Frontend: React, Next.js, Hotwire (Turbo & Stimulus), Tailwind CSS - Databases: PostgreSQL, MySQL, Redis, pgvector - AI/LLM: OpenAI API, RAG, MCP servers, embeddings, Claude Code - Infrastructure: AWS, Docker, Heroku - Integrations: Stripe, GoHighLevel, Google Places API, Google Calendar Why Clients Choose to Work With Me - 6+ years building and scaling production Rails SaaS products - Real AI systems built from scratch โ€” RAG, MCP, LLM workflows โ€” not API wrappers glued together - Experience across PropTech, healthcare, and e-commerce domains - Clear communication, no jargon, no disappearing after the deposit - I take on legacy code other developers avoid and modernize it without breaking what works Whether you need to add AI capabilities to an existing Rails app, build a SaaS product from scratch, or fix a codebase someone else left behind, I focus on shipping something that runs in production โ€” not something that only looks good in a pitch. Full Stack Developer | MERN Stack Developer | React Developer | Node.js Developer | Next.js Developer | Full Stack React Developer | Node.js Full Stack Developer | React Node Developer | MERN Developer | Full Stack MERN | MERN Stack | SaaS Developer | Full Stack SaaS Developer | Multi-Tenant SaaS | SaaS Application Development | SaaS Expert | Next.js Full Stack Developer | eCommerce Developer | Laravel Developer | Python Developer | API Developer | REST API Full Stack Developer | GraphQL Developer | Backend Developer | NestJS Developer | Web Application Developer | Full Stack Development | Web Development | AI App Full Stack Developer | AWS Full Stack Developer Developer | Docker | DevOps | React Full Stack Developer | Microservices | Full Stack Developer

  • Ruby
  • Ruby on Rails
  • MySQL
  • PostgreSQL
  • JavaScript
  • Python
  • Node.js
  • React
  • Docker
  • Redis
  • Amazon Web Services
  • Artificial Intelligence
  • Large Language Model
  • Retrieval Augmented Generation
  • AI Chatbot
  • SaaS Development
  • API Integration
  • AI Development
  • Full-Stack Development
  • Software Development
Vrezh U.

Vanadzor, Armenia

$35/hr
4.8
13 jobs

I am a dedicated Software Engineer with 8+ years of hands-on experience building and maintaining production web applications across different domains. I specialize in full-stack development, creating reliable and scalable solutions using modern frontend and backend technologies. Throughout my career, I have worked on commercial products including AI-powered test automation platforms, healthcare systems, identity verification solutions, and real estate platforms. My experience includes developing frontend applications, backend services, REST APIs, database integrations, cloud-based solutions, real-time communication, and improving application performance. Technical Skills: Programming Languages: TypeScript, JavaScript (ES6+), C, C++, Swift, Objective-C, Java Frontend: React, React Native (Expo), Redux Toolkit, Tailwind CSS, HTML/CSS, jQuery, Recharts, Mapbox, Vite Backend: Node.js, Express.js, Koa, REST APIs, GraphQL, Socket IO, Sequelize, AWS Lambda, MCP, AI integrations Databases: PostgreSQL, MySQL, MongoDB, Redis, SQLite Cloud & DevOps: AWS (Lambda, S3, SES, Bedrock), Docker, Docker Compose, Kubernetes, CI/CD, GitHub Actions, Jenkins Messaging & Testing: RabbitMQ, Jest, Playwright, Swagger Tools & Platforms: Git, GitHub, JIRA, Splunk, Cursor, Copilot, Xcode, Qt Creator, CMake Additional Experience: Electron, OpenCV, STL, Core Data, UIKit, Foundation I am passionate about building high-quality software, solving complex technical challenges, and collaborating with teams to deliver reliable and maintainable solutions.

  • iOS
  • Spring Framework
  • Java
  • C++
  • Python
  • JavaScript
  • Swift
  • React
  • CMake
  • Git
  • Django
  • Desktop Application
  • Docker
  • Database
  • RESTful API
Afaq F.

Lahore, Pakistan

$20/hr
5.0
1 jobs

๐Ÿš€ I build scalable backend systems and full-stack applications for SaaS platforms, startups, and enterprises โ€” with 5+ years shipping production Java / Spring Boot systems, and hands-on MERN stack experience when projects call for a JavaScript-based full-stack build. I currently work as a Senior Software Engineer on Xcelerate, a microservices-based SaaS platform for restoration companies, where I develop and maintain 20+ Spring Boot microservices, build real-time messaging systems, and integrate third-party platforms like QuickBooks, RingCentral, Zapier, and Encircle. What I can help you build: โœ” Java & Spring Boot backend systems โœ” Microservices architecture & REST APIs โœ” MERN stack applications (MongoDB, Express, React, Node.js) โœ” Third-party integrations (QuickBooks, Stripe, Twilio, Zapier, RingCentral) โœ” Cloud deployments โ€” AWS, Azure, GCP โœ” CI/CD pipelines (Jenkins, GitHub Actions), Docker โœ” Database design & query optimization (PostgreSQL, MySQL, MongoDB) โœ” Legacy system modernization (Java 8 โ†’ Java 21 migrations) Highlights: Led backend development across 20+ microservices for Xcelerate, a live SaaS platform for restoration companies Migrated infrastructure from VMs to Azure App Services, implementing Azure Front Door for traffic routing and load balancing Built WS Glam, a full-stack e-commerce platform from scratch โ€” frontend, backend, admin panel, payment integration, and role-based access control Integrated Stripe subscription billing for Remojo and overhauled its backend architecture for scale Built a custom AML (Anti-Money Laundering) system from scratch, including case management tools and fraud detection workflows I think in terms of failure modes before I write code โ€” what happens when a webhook fires twice, when an API rate-limits mid-sync, when a migration needs to run without downtime. I communicate proactively and hand off production-ready code with documentation to match. Let's talk about what you're building โ€” I'll give you a straight technical assessment and a clear path forward.

  • Java
  • Spring Boot
  • React
  • Tailwind CSS
  • DevOps
  • Jenkins
  • Amazon EC2
  • Azure DevOps
  • PostgreSQL
  • Google Cloud Platform
  • Elasticsearch
  • Docker
  • MongoDB
  • QuickBooks Enterprise
  • Amazon QuickSight
  • CI/CD
  • Stripe
  • FinTech

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Don't just take our word for it

What does a Sinatra Framework developer do?

A sinatra framework developer builds lightweight Ruby web applications by defining precise HTTP routes and managing request logic without the overhead of larger frameworks. This role focuses on creating modular services where code clarity and direct control over the request lifecycle matter more than convention-based scaffolding. You write clean route handlers that map URLs to specific actions, configure middleware for security and session management, and render dynamic views using template engines. The work demands a deep understanding of the Rack interface since Sinatra operates as a thin layer on top of this standard.

  • Implement HTTP route handlers that accept GET, POST, PUT, and DELETE requests, parse URL parameters, and return appropriate response bodies or status codes. You define these endpoints explicitly in the application code, ensuring each path triggers the correct business logic without relying on automatic routing generators. This includes handling query strings, form data, and JSON payloads directly within the route block to process user input accurately.
  • Configure application settings and middleware components to manage sessions, logging, static file serving, and error handling behaviors. You use the Sinatra settings API to enable or disable features such as cookie-based sessions via Rack::Session::Cookie or request logging through Rack::CommonLogger. This setup ensures the application maintains state across requests and records diagnostic information for debugging while keeping the runtime environment secure and performant.
  • Create and render dynamic templates using engines like ERB or Haml, integrating layouts and local variables to generate HTML responses for users. You structure view files separately from route logic, passing data from controllers to templates to maintain a clear separation of concerns. This involves writing helper methods that format data or generate reusable UI snippets, which the templates call during the rendering process to produce consistent and valid markup.
  • Write automated tests using Rack::Test to simulate HTTP requests and assert that routes return expected status codes and response content. You build a test suite that covers normal operations, edge cases, and error conditions, verifying that before and after filters execute correctly around each request. This practice catches regressions early and confirms that middleware protections, such as those provided by Rack::Protection, function as intended against common web attacks.

How to hire a Sinatra Framework developer on Upwork

Step 1: Post a job

Define your Ruby web application needs clearly so candidates understand the scope. Use the Job Post Generator powered by Umaโ„ข, Upwork's Mindful AI to draft a precise description from a few sentences. You can write a new post, update a saved draft, or reuse an existing post.

  • Specify requirements for implementing HTTP routes with URL patterns and parameter handling in a Sinatra app.
  • List necessary template engines such as ERB or Haml for rendering views with layouts and locals.
  • Request experience configuring Sinatra settings for sessions, logging, static files, and error behavior.

Step 2: Evaluate candidates

Look for portfolios that demonstrate clean route definitions and effective use of middleware. Uma can run instant video interviews and build shortlists with side-by-side comparisons to help you assess technical fit.

  • Verify their ability to add request lifecycle logic using before and after filters alongside shared helpers.
  • Check for examples of automated tests written with Rack::Test to simulate requests and assert response results.
  • Confirm they configure built-in behaviors like request logging and exception handling correctly.

Step 3: Interview your top choices

Discuss specific implementation strategies for your application architecture. Schedule and conduct interviews within Upwork Messages to receive an immediate transcript and summary after each session.

  • Ask how they manage per-user state across requests using Sinatra session settings.
  • Discuss their approach to integrating Rack middleware components such as Rack::Session::Cookie.
  • Review their method for organizing template files and layout structures within the project.

Step 4: Agree on scope and begin work

Set clear milestones for code delivery and testing coverage. Use Upwork Messages and the contract workroom for communication and project management, plus identity verification, payment protection, hourly tracking, and project funds for security.

  • Define deliverables including working Sinatra application code with routes, filters, and helpers.
  • Require an automated test suite covering route behavior using a Rack-based testing approach.
  • Specify configuration tasks for sessions, logging, static folders, and optional security extensions like Rack::Protection.

Upwork is not affiliated with and does not sponsor or endorse any of the tools or services discussed in this article. These tools and services are provided only as potential options, and each reader and company should take the time needed to adequately analyze and determine the tools or services that would best fit their specific needs and situation.

The rates and information provided in this article are based on current data and industry sources available at the time of publication. Freelance rates can vary depending on factors such as experience, location, project scope, and market conditions. Readers are encouraged to conduct their own research to confirm current rates and trends, as this information may change over time.

How much does hiring a Sinatra Framework developer cost?

$500-$1,500 per project is a typical range for focused Sinatra Framework developer work. Final pricing depends on scope, technical complexity, required integrations, source-material quality, revision needs, and the freelancer's experience level.

Route implementation

$500-$1,200/project

Entry-level to mid-level
  • HTTP handlers with URL patterns and parameter logic
  • ERB or Haml view files with layout structures
  • Rack::Test assertions for endpoint behavior

Configuration setup

$1,200-$2,500/project

Mid-level
  • Session management and logging configuration
  • Rack components for static files and error handling
  • Before and after request lifecycle hooks

Security integration

$2,500-$4,500/project

Mid-level to senior-level
  • Rack::Protection middleware against web attacks
  • Input sanitization and secure session handling
  • Security review of route access controls

API development

$4,500-$7,000/project

Senior-level
  • RESTful routes returning JSON response bodies
  • Shared utility methods for request processing
  • API usage guide and test coverage report

Full application build

$7,000-$12,000/project

Expert-level
  • Modular Sinatra app with organized route files
  • Database connections and external service hooks
  • Production-ready code with automated test suite

Frequently asked questions

Is hiring a Sinatra Framework developer worth it?

For most businesses, yes: hiring a Sinatra Framework developer is worthwhile. This specialist builds lightweight Ruby web applications without the overhead of larger frameworks. They configure precise HTTP routes and manage session state for focused microservices or simple web tools.

How do I evaluate Sinatra Framework developer candidates?

Review how candidates structure route handlers and implement before/after filters for request logic. Ask them to write a Rack::Test suite that simulates a POST request and asserts the correct response status and body content.

What tasks does a Sinatra Framework developer handle?

They define URL patterns for HTTP requests and render views using ERB or Haml templates. These developers also configure application settings for logging, error handling, and static file serving.

Which tools does a Sinatra Framework developer use?

They rely on the Sinatra settings API to control runtime behavior and Tilt for template rendering. Developers often integrate Rack middleware components like Rack::Session::Cookie for user state management.