Hire Top Freelance RSpec Developers

Carlos Aguilar

I’m a senior mobile + backend engineer with 20+ years in software (PHP since 2002; professional since 2005) and 10+ years building mobile apps. I help teams ship and stabilize real products—especially apps that are “almost done” but stuck on crashes, performance, flaky networking, or release blockers. What I can help you with (fast, practical): • iOS (Swift, SwiftUI, UIKit): crash fixes, performance/memory, concurrency issues, architecture cleanup • Flutter (iOS/Android/macOS): reliability, state consistency, networking/retry behavior, release readiness • Backend stability (PHP/Laravel or custom, Python/Django, Rails): idempotency, queues, DB performance, webhook safety • Firebase + mobile reliability: Auth/Firestore rules, Cloud Functions patterns, analytics/instrumentation • Monetization + shipping: RevenueCat/IAP reliability, App Store Connect/Play Console, CI/CD, rejection handling Recent work includes taking a messy iOS codebase (CakeClub) to production-ready with a Firebase Cloud Functions v2 backend, stronger security patterns, CI/release automation, and RevenueCat integration; and delivering major cross-platform Flutter work (BillBlaster) including design refinements, admin tooling, and push notification features. If you come with logs/screenshots (Crashlytics traces, network errors, repro steps), I’ll give you a clear diagnosis and a prioritized fix plan—and if it makes sense, I can execute the fixes as a focused sprint.

Mark Nyon

I’m a Technical Lead and Full-Stack Developer with 17+ years of experience delivering robust web applications and SaaS platforms. I have led engineering teams through complex projects, balancing hands-on development with mentoring and process improvements to consistently meet aggressive deadlines. Notably, I helped scale infrastructure and improve performance for SaaS products used by tens of thousands of users. I excel at driving feature delivery end-to-end—whether implementing APIs, optimizing workflows, or guiding teams—as a dependable executor and problem solver.

Dan Brown

**Full-Stack Software Engineer** * Software engineer with 10+ years of experience building full-stack MVPs and APIs, mostly in Ruby on Rails * A bunch of experience with React, jQuery and vanilla JavaScript **Data Science** * Experienced in data science (both in R and Python) * MS in Analytics from Georgia Tech * Experienced in numpy/pandas, regression, classification, and other machine learning models For bigger projects, I have experience leading dev teams (including designers) and being a product manager.

Rahul Singh

With over a decade of experience in full-stack development, I specialize in **Ruby on Rails, custom eCommerce solutions** (Spree, Solidus), **ReactJS**, and **DevOps**. My expertise spans designing and developing scalable, distributed cloud-based applications with a strong foundation in **database architecture** and **system refactoring**. As a technology leader, I’ve successfully delivered complex, high-impact projects across industries including **Real Estate, Finance, Healthcare, Marketing**, and **eCommerce**. My portfolio includes building sophisticated eCommerce marketplaces, **SaaS platforms**, and multi-channel selling applications. I am passionate about crafting innovative, robust software solutions tailored to meet diverse business needs. **Key Expertise:** - **Backend:** Ruby on Rails, building and scaling RESTful APIs. - **Frontend:** ReactJS, JavaScript, responsive UIs with Tailwind CSS, and Bootstrap. - **eCommerce Solutions:** Spree, Solidus, custom marketplaces, multi-tenant SaaS platforms. - **Database Architecture:** MySQL, PostgreSQL, MongoDB, Redis, Cassandra, optimized for high performance and scalability. - **DevOps:** CI/CD pipelines (CircleCI, AWS Pipeline), containerization (Docker), cloud platforms (AWS, GCP, Heroku, DigitalOcean). - **Test-Driven Development:** Expertise in TDD using RSpec, ensuring high code quality and maintainability. In addition to my technical expertise, I have a strong commitment to **open-source contributions** and have developed multiple **Ruby/Rails/Spree extensions**. I also bring a wealth of experience in **refactoring legacy code bases**, implementing **performance optimisation**, and improving **scalability** and **security**. My passion lies in helping businesses unlock their full potential through technology, and I am always eager to collaborate on long-term, impactful projects. Let’s build the future, one line of code at a time. Best regards, Rahul Singh

K M Rakibul Islam

Freelance RSpec Developer5.0 (2548 reviews)

Experienced (18+ years) developer and friendly Ruby on Rails and React/Next.js/Redux Developer/Mentor (with passion for helping others learn) | ★ 3,655+ 5 ★ sessions/jobs. 9+ years on top of the Codementor Ranking ★ https://www.codementor.io/ruby-on-rails-experts I am a Senior Software Engineer from Toronto, currently working as a Ruby on Rails and React/Redux Developer at theScore Inc. I am passionate about helping and mentoring people, especially those who are new to web development and the programming world. I am specialized in explaining the core concepts of Ruby and Rails, Javascript, React, APIs and everything else along with the best practices. I focus on the learning experience of my students and make sure they get exactly what they want. I have excellent academic track records (Bachelor of Science in Computer Science and Masters in Computer Engineering from the University of Toronto) along with strong development and industry experience in Software Development and Web Development (18+ years coding experience in total). I have helped more than 800 individuals here at CodeMentor (with 3,655+ 5 ★ sessions) with their projects implementation, bug fixes, architecture advices, performance improvements etc. I have worked with a bunch of CEOs and CTOs of YC start-ups and helped them with their projects. Made long term relationships with many of them which I help in a regular basis today. I have helped a LOT of bootcamp students here at CodeMentor and helped them build their web development career path and getting jobs after the completion of their bootcamp cohorts. Here at CodeMentor, I have helped people from all levels: From someone who is brand new to programming to 30+ years of experienced Senior Software Engineers, Product Managers and everyone in between. It's been an amazing journey here at CodeMentor for the last 8+ years! :-) I started programming and solving problems in 2006, at the age of 18. Since then, I wrote programs in a variety of programming languages such as C, C++, Java, PHP, Ruby, Python, Javascript, etc. These days, I use Ruby and Rails and React JS as my primary programming languages and frameworks. I can help with debugging your issues as well as refactoring your code according to the best practices and conventions out there. Helping people is my passion and motto in life. If you think I can help you in any way, please get in touch! Specialties: * Building scalable and performant backend APIs in Ruby on Rails (Active Model Serializer, GraphQL, Grape, Jbuilder, RABL, etc.) for android, iPhone or web applications. (For more than 12 million users). * Integration of backend APIs with Javascript frontend framework (ReactJS) using JSON Web Token (JWT). * Built highly scalable Push Notification System for theScore sports application (For ~10 million users). * Implemented instant player, team and news article search for the theScore and theScore eSports apps which have more than 6 million monthly active users using ElasticSearch and Rails. * Backend Ruby on Rails Development (With scaling, performance optimizations, database query optimizations, caching best practices, etc.). * Test Driven Development with clean code and best practices. * Web Scraping (Nokogiri, Mechanize) (Scrape data from anywhere on the internet!). * Reverse engineering complex APIs and web applications to write automated scripts to mimic and automate user behaviour and extract required data. * Explain concepts/solutions clearly and concisely according to the level of the client/student. (Helped over 800 people on CodeMentor with 3,655+ 5 ★ sessions) * Giving architecture advice for your application. Explain which tools/gems to use and why. * Setting up SSL certificates for Rails application (Nginx server) on AWS EC2 instance and securing your application. * Suggesting best practices and focusing on the best learning experience and long-term achievements. * Showing cool tips and tricks that I have learned over the past 18+ years (and still learning!) as a professional Ruby on Rails developer to be more productive and efficient at work. * Upgrading Ruby/Rails versions for your existing application. * Finding bottlenecks and Optimizing performance for your slow Rails applications. * I can help you to prepare for interviews for Ruby on Rails developer position, or any other Software Development position. I have successfully guided many developers who got their dream jobs after practicing coding interviews with me!

Arup Rakshit

I am a freelance web developer working out of India. My weapons of choices are : HTML, CSS, Javascript, SQL, Ruby, Ruby on Rails, React JS. I literally spend as much hours as possible every day on coding.

Greg Gorlen

I'm a full stack software engineer, technical writer and computer science educator. I enjoy testing, debugging, refactoring, application design, maintaining projects and teaching. My primary technologies are JavaScript, TypeScript, React, Express (PERN stack), Playwright, Puppeteer, Python, Flask and C. See my [Stack Overflow tags](https://stackoverflow.com/users/6243352/ggorlen?tab=tags) for more technologies ordered roughly by my interest and experience. In addition to Stack Overflow, I'm active on [Code Review Stack Exchange](https://codereview.stackexchange.com/users/171065/ggorlen). Feel free to peek at a few of these reviews to get a sense of the insights I can offer your code. I'm looking forward to hearing about your project! __{Profile picture by the wonderful [Emily Huston](https://emilyhuston.github.io) ❤️}_

Abdulmajid Hamza

I am an experienced web and mobile application developer with more than 4 years experience with client projects. I have participated in developing quality grade software for varying range of clients. I have keen interest in problem solving and software debugging. I also managed a software development team to deliver client software for a few projects. I am a lover of good code and standard software development practices (TDD, SOLID, etc).

Kristians Kuhta

Passionate full-stack Ruby on Rails and smart contract developer with 5 years of experience. Strong background in the development of internal systems that allow businesses to orient their operations around digital documents rather than physical ones. I have 5 years of experience in **Ruby on Rails**, **JavaScript**, **PostgreSQL**. I specialize in enterprise-level **Code Reviews** and **Integration testing**. As well as I have worked with technologies like: * Test-driven development * RSpec testing framework * Capybara feature testing framework * Jest * REST APIs * Redis database * Docker * jQuery * StimulusJS * Turbo.js, Hotwire * React

Seva Rybakov

I am an expert, full-stack web engineer. I develop clean and well-tested backends in Ruby on Rails and Nodejs. That being said, I really enjoy writing React.js front-ends. Ping me and we can discuss how I can help you!