Jobs Ruby

We are looking for a Senior Ruby on Rails Developer to join a product engineering team working on a mature, high-traffic platform with a large and well-established domain model.

Project: A long-running digital platform in the travel, hospitality, and marketplace domain. The product manages complex workflows around properties, reservations, deposits and exchanges, billing, and member onboarding. You'll work on a large Ruby on Rails application, contributing to new features, performance improvements, integrations, and the continuous evolution of the platform.
 

This is a backend-focused Rails role. You'll work primarily with Ruby on Rails, databases, background processing, APIs, and third-party integrations while contributing to a large and established codebase.
Tech Stack: Ruby, Ruby on Rails 7.x, Rails Engines, MySQL, Redis, Memcached, Solr, Sidekiq, Clockwork, ActionCable, ActiveAdmin.
Authentication & Security: JWT, CanCan, bcrypt, role-based authorization.
Integrations: Stripe, AWS S3/CloudFront/SNS, Twilio, transactional email, product analytics, feature flags, geolocation.
Testing: Minitest, RSpec, FactoryBot, VCR/WebMock, Capybara/Selenium.
 

Responsibilities:
Develop and deliver backend features using Ruby on Rails;
Work effectively with a large, established Rails codebase and make well-tested, maintainable changes;
Design and implement database changes, models, service objects, APIs, and business logic;
Develop and maintain background jobs and scheduled processes using Sidekiq and related tools;
Build and maintain integrations with third-party services such as Stripe, AWS, and Twilio;
Write and maintain automated tests, including unit, integration, and API tests;
Analyze and optimize application performance across the database, search, caching, and background processing layers;
Contribute to improving system reliability, code quality, and maintainability;
Participate in code reviews and collaborate closely with other engineers and product teams.
 

Requirements:
-4+ years of professional experience with Ruby on Rails, including production experience with large, established applications;
-Strong experience with Ruby on Rails 7.x;
-Solid knowledge of MySQL and/or PostgreSQL, including schema design, migrations, indexing, and query optimization;
-Strong experience with Sidekiq or similar background job processing tools;
-Experience building and maintaining RESTful APIs;
-Experience integrating third-party services and APIs;
-Strong testing experience with Minitest/RSpec and related testing tools;
-Experience with Git and pull-request workflows;
-Comfortable working with and improving a large, long-lived codebase;
-Good written English and clear communication skills.

Nice to Have:
Experience with JavaScript, Vue, Stimulus, or Hotwire;
Experience with HTML, CSS, and Sass;
Experience with Solr, Elasticsearch, or other full-text search technologies;
Experience with Stripe or other payment and billing integrations;
Experience with ActiveAdmin or similar admin frameworks;
Familiarity with Docker and Kubernetes;
Familiarity with CI/CD, including CircleCI or GitHub Actions;
Familiarity with AWS, particularly S3, CloudFront, or SNS;
Experience with monitoring and observability tools such as Prometheus or APM solutions;
 

FTE: Full-time (40 h per week)
Timeline: 3-6 months (tbd)
Start: ASAP
English: B2
Recruitment process: a tech check with our client, then an interview with the main client

The company
A well-established B2D (business-to-developer) SaaS platform operating at significant scale. Their product is infrastructure-level - real-time connectivity used by developers worldwide.

The team
~6–7 people: tech lead, PM, delivery manager, 3 web engineers + contractors. Small, tight-knit, opinionated. Standups Monday and Friday.

The role
One senior hire. This is a product-minded engineering role, not ticket execution. They’re shifting away from reactive delivery toward engineers who understand customers and drive outcomes.

Tech stack
React + TypeScript (frontend), Ruby on Rails (backend), some Node/TS services, Postgres.

What they’re looking for

• Developer empathy - you build tools for developers, you get the frustrations firsthand
• Product thinking - question requirements, propose what should be built
• Ownership - concept to shipped with minimal hand-holding
• Proactive communicator
• Comfortable with AI coding assistants (they use them actively)
• Design + UX intuition

About the Project

AI Interview Platform (client name undisclosed) — a leading technical interviewing platform used by fast-growing startups and large enterprises worldwide. It pairs experienced engineers with standardized interview frameworks to enable fair, high-signal, and scalable hiring for software engineers globally.

What You'll Do

• Conduct live technical interviews with software engineering candidates worldwide via the platform.
• Assess coding skills, problem-solving abilities, technical knowledge, and communication while creating a professional and inclusive candidate experience.
• Provide structured, objective feedback based on established evaluation criteria to reduce bias and improve hiring quality.
• Collaborate with the client’s team to test, refine, and improve interview content, processes, and platform features.
•  

Must Have

• 4+ years of professional experience as a Software Engineer/Developer.
• Strong Ruby / Ruby on Rails proficiency
• Working knowledge of frontend technologies (JavaScript, React, or similar).
• Solid understanding of algorithms, data structures, and software engineering fundamentals.
• Excellent English communication skills (spoken and written).

• Professional demeanor, ability to deliver objective assessments, and reliable setup (webcam, microphone, stable internet).

   

Nice to Have

• Prior experience conducting technical interviews (DS&A, system design).
• Mentoring, coaching, or technical leadership experience.
• Interest in talent assessment, interviewing best practices, or inclusive hiring.
   

Location: EU / Remote (Ukraine)

Type: Freelance full-time (first 3 months), with option to go part-time later.

We are looking for an experienced Senior Ruby + React Developer / Architect to join a product-focused engineering team building a large-scale B2D (business-to-developer) SaaS platform. You will help shape developer-facing products used worldwide, taking ownership of features from concept to production while influencing both technical and product decisions.

This is not a feature factory role—you'll work closely with the team to understand customer needs, challenge assumptions, and build solutions that deliver meaningful value to developers.
 

Core Competence:
 

• 5+ years of professional experience in software development, with strong expertise in Ruby on Rails and React + TypeScript.
• Proven experience designing, building, and maintaining scalable web applications in production environments.
• Strong frontend engineering skills with React, modern TypeScript, and component-based architecture.
• Solid backend development experience using Ruby on Rails, including API design and application architecture.
• Experience working with PostgreSQL and designing efficient, maintainable data models.
• Ability to take ownership of features throughout the entire development lifecycle—from discovery and design to implementation and release.
• Strong product mindset with the ability to challenge requirements and propose better technical and product solutions.
• Experience building products for developers or a strong understanding of developer experience (DX) principles.
• Comfortable working independently with minimal supervision in a fast-paced product environment.
• Excellent communication skills and the ability to collaborate effectively within a small cross-functional team.
• Hands-on experience using AI-powered development tools and coding assistants to improve engineering productivity.
• Strong understanding of software architecture, clean code principles, and modern engineering best practices.
   

Preferred Qualifications:
 

• Experience working on B2D (Business-to-Developer) or developer tooling products.
• Knowledge of Node.js and TypeScript backend services.
• Experience designing scalable frontend architectures and improving application performance.
• Strong UX and design intuition with an understanding of creating intuitive developer experiences.
• Experience influencing product direction and collaborating directly with product managers and technical leadership.
• Familiarity with Agile development methodologies and iterative product delivery.
• Previous experience in an architectural or technical leadership role.
   

What We Offer You:
 

• Product Ownership: Build features that directly impact developers using a globally adopted infrastructure platform.
• Architecture Influence: Contribute to technical direction and help shape the evolution of the product.
• Modern Technology Stack: Work with Ruby on Rails, React, TypeScript, PostgreSQL, and modern engineering practices.
• Collaborative Team: Join a small, experienced, and highly autonomous engineering team where your ideas matter.
• AI-Driven Development: Work in an environment that actively embraces AI coding assistants to improve productivity.
• Meaningful Impact: Help build infrastructure-level software powering real-time connectivity for developers around the world.
• Flexible Remote Environment: Work full-time with an international team focused on engineering excellence and product quality.

Who We Are

PAR Retail, with its Open Commerce® product suite and patent pending Wallet Steering® System, empowers Convenience & Fuel Retailers to gain more share of wallet and customer lifetime value than possible with any other solution provider. PAR Retail’s unified Open Commerce product suite consists of: Activate for Intelligent 1:1 Loyalty, Transact for Contactless Commerce, and Experience for Cross-Channel Customer Experiences. PAR Retail’s solutions are supported by a set of subscription-based program management services and are contractually backed by its 1.5X Performance Guarantee.

Technology Stack:

Ruby, Ruby on Rails, Postgres, Redis, Sidekiq, GraphQl, RabbitMQ

Requirements:

- Practical experience building systems in Ruby on Rails

- At least 6 years industry experience or equivalent

- Experience building and maintaining backend APIs, including design, implementation, evolution, and maintenance

- Familiarity with TypeScript, or similar modern strongly-typed language

- Proficiency using a variety of database technologies, both relational and non-relational

- Strong understanding and familiarity with CI/CD pipelines and automated tests

- An ability to work in service-based architectures as well as well-factored Rails monolith applications

- Highly independent and able to effectively self-organize and prioritize work

- The ability to write clean code, and the discipline to write effective automated tests to deliver high-quality system improvements

- An ability to effectively break down larger bodies of work for delivery as a series of small, self-contained changes to the system

- Excellent spoken and written communication skills

- BS/MS degree in Computer Science, Engineering, or equivalent years of professional working experience

Bonus Points

- Experience with NodeJS and React

- Experience in the retail and/or fuel & convenience industries

- Experience working in distributed teams

- Experience with Nest.js and/or GraphQL

Responsibilities:

- Collaborate closely with other Engineers, design and implement new functionality based on product objectives and requirements.

- Work with the broader product engineering team to plan and coordinate feature and functionality improvements, as well as resolve bugs and execute technical enhancements, that cross-cut large parts of our platform.

- Work to continually learn, improve technology skills, expand knowledge of the our platform technologies, and gain increasing versatility across the breadth of our platform systems.

- Expand APIs and business logic, and as needed write or revise customer-facing API documentation.

- Work with our infrastructure team to enable and enhance highly-available, performant, and well-instrumented backend applications and services that run in our customer environments at substantial scale.

- Support operations and infrastructure teams for issue resolution on relevant applications or services running in production environments.

PAR Retail Offers:

- Long-term employment;

- Competitive compensation with regular performance-based salary and career development reviews;

- Paid vacations and sick leaves;

- Flexible working hours;

- A unique and friendly environment where everyone can explore and learn new technologies.

Simulmedia is seeking an experienced Senior Backend Engineer to join our engineering team, working on the backend and data infrastructure powering our TV advertising platform - spanning National Linear and CTV. This role sits within a distributed system of up to ~30 microservices, and you'll be primarily responsible for building, scaling, and operating backend services - with secondary exposure to backend-for-frontend work in TypeScript/Node.

In this role you will work closely with product managers, designers, and data engineers to ensure seamless integration of analytics features into the platform. The ability to frequently iterate and deliver high-quality features that are owned end-to-end is crucial in this role.

We're looking for someone who takes ownership, communicates directly and honestly, and cares about the reliability and craft of the systems they build - not just shipping features but understanding how they behave in production.

Location: Ukraine is mandatory. Our offices are located in Kyiv and Lviv. Teams are located in Kyiv and Lviv and primarily work remotely with occasional offline meetings.

Key Responsibilities:

• Design, build, and maintain backend services in Ruby (Roda) operating within a large-scale distributed microservice architecture.
• Contribute to backend-focused TypeScript/Node.js work, including API design and tRPC procedures, in support of Next.js applications.
• Own service reliability: instrumentation, monitoring, and observability across services (tracing, metrics, structured logging).
• Collaborate closely with data engineers on data pipelines, ETL processes, and ensuring clean, well-modeled data flows between services.
• Investigate and resolve production incidents; contribute to and follow oncall/runbook practices.
• Design and evolve APIs with strong attention to authentication, authorization, and security best practices.
• Participate in code reviews, pair programming, and knowledge-sharing sessions to ensure high-quality, maintainable code.
• Write thorough unit and integration tests for backend services
• Work independently while communicating clearly across a distributed, cross-functional team

Qualifications:

• Bachelor’s degree in Computer Science, Computer Engineering, or a related technical field.
• 5+ years of professional Ruby backend development experience; prior experience may be with Rails, Roda, Sinatra, or similar - deep Roda-specific knowledge is not required, as long as the underlying Ruby fundamentals are strong.
• Experience operating within a distributed systems / microservice architecture.
• Solid working knowledge of observability tooling - OpenTelemetry, Datadog, Grafana, Prometheus, or equivalent - including setting up tracing, metrics, and alerting, not just consuming dashboards.
• Experience with error tracking/monitoring tools such as Sentry, Honeybadger or equivalent.
• Hands-on experience in TypeScript and Node.js, with practical experience in Next.js for backend/API-layer work.
• Experience with tRPC or comparable typed API frameworks.
• Solid experience with AWS and its core services (e.g. EC2, S3, RDS, SQS/SNS, ECS/EKS), including infrastructure-as-code with AWS CDK, plus containerized applications (Docker).
• Experience designing and evolving APIs, including auth, security, and versioning concerns.
• Experience working in a large distributed system with dozens of independent services, potentially written in different languages; ability to quickly get up to speed in unfamiliar code and trace a request's path across multiple services end-to-end.
• Experience with CI/CD pipelines - we currently use Jenkins and are actively migrating to GitHub Actions, so comfort with either (and ideally migration experience) is valuable.
• Ability to use AI coding tools (e.g. Claude Code, Codex, Cursor, or similar) effectively to speed up development, debugging, and code comprehension.
• Strong communication skills; ability to work independently and take ownership of services end-to-end.
• Ability to communicate effectively with the U.S.-based teams and work 11:00 AM - 8:00 PM EEST (11:00 - 20:00).

Bonus Points for:

• Python experience (data tooling, scripting, or services)
• Experience in AdTech or digital advertising/media analytics
• Prior experience in a service migration, decomposition, or platform-modernization effort

Interview Process:

1. Pre-screening (30 mins)
2. Technical Interview (1h)
3. System Design (1.5h)
4. Product Interview (30 mins)
5. Offer.

About Us

At UITOP, we design and develop scalable B2B SaaS platforms across industries like logistics, finance, construction, and so on.

Job Summary
As a Ruby on Rails Developer, you’ll focus on backend development and work on AI-powered features, with AI being a core part of the product. You’ll join a team of 5 developers, a PM, a designer, and 2 QA engineers.

About project
We are building a US-based SaaS product for construction companies, focused on automating the permitting and approval processes in the construction industry.

What do you have

• At least 2 years of experience with Rails. 
• Proficient in Backend: you have at least two years of experience with Ruby and Ruby on Rails (most important), ideally 2-4 years.
• Frontend: Vanilla JavaScript, Hotwire with StimulusJS & Turbo a bit.
• Knowledge of Data Stores: Postgres and Redis; Sidekiq; S3. 
• Experience with Stimulus, TailwindCSS. 
• Experience with cloud environments, Terraform, networking and security concepts. 
• Good English communication skills (B2+), be ready to communicate with clients.

Bonus points

• Experience with cloud environments (AWS, GCP, or Azure), Terraform, networking, and security, as well as DevOps practices.
• Experience with AI integrations and AI-powered automation.

What we have

• Regular performance and salary reviews. 
• Working with complex large-scale SaaS projects, from 6 months.
• 18 working days of vacation and 10 sick days.
• Compensation 50% for professional development cources. 
• Free Internal English classes.
• Company equipment. We’ll provide a laptop after 6 months of work. 
• Financial compensation of coworking 100% (during blackouts).
• Flexible work schedule, remote.

Cropwise Operations is a global leader in digital agritech solutions, operating in over 50 countries and helping optimize business processes and improve the efficiency of agronomic decision-making.  

We are looking for a skilled Ruby on Rails Developer to join our team.

What we expect from a candidate:

- Preferably 3+ years of Ruby on Rails development experience.

- Strong knowledge of Rails.

- Experience with testing frameworks like RSpec and Capybara.

- Testing with RSpec/Capybara.

- Basic knowledge of ES6 + React.js.

- Experience with JavaScript.

- Standard Rails application deployment stack (Git, CI, Capistrano, *nix).

- Knowledge of HTML/CSS.

What exactly will you need to work with:

- Backend on Ruby on Rails 7.0 (Ruby 3.2).

- PostgreSQL + PostGIS database (handling large geospatial datasets).

- Job processing with Resque + Redis.

- Testing on RSpec + Capybara + CI.

- Partially frontend on React.js (ES6, JSX).

What else can you work with?

- Algorithms for processing large amounts of geodata.

- Reception and processing of binary data (Ruby eventmachine).

- Working with RabbitMQ.

- AWS, Google Cloud, Kubernetes.

- Visualization and work with geodata on the frontend (Mapbox GL JS).

Hiring process:

- Intro call;

- Test Task;

- Final Interview;

- Offer.

The company offers:

- Opportunity to be a part of a best-in-class product that is used by thousands of companies around the world.

- Participation in complex technical tasks and challenges.

- Environment where you need to seek and implement unique engineering and technical solutions.

- Trainings and development programs.

- Flexible work formats: remote, office or hybrid.

- Health and life insurance for employees and your family members.

- 32 working days of paid annual leave and sick leave.

About Cropwise Operations

Cropwise Operations is a SaaS platform for farmers, leveraging cutting-edge technologies such as computer vision, big data, and AI to deliver actionable insights and improve agricultural outcomes.

For seekers, cooperation with Cropwise Operations is an opportunity to be part of a best-in-class product used by hundreds of companies around the world, and to deal with complex technical tasks in the field of neural networks and machine learning with the need to constantly improve their knowledge and skills, to find and implement unique engineering and technical solutions.

Who we are:

Adaptiq is a technology hub specializing in building, scaling, and supporting R&D teams for high-end, fast-growing product companies in a wide range of industries.
 

About the Product:

Our client develops a cloud-based platform for managing corporate ground transportation within a multi-billion-dollar global market. The solution brings together various transportation providers—including corporate fleets, ride-hailing platforms, taxi companies, and limousine services—within a single system that enables businesses to optimize operations and control transportation costs.

The platform is used by a substantial number of the world’s largest companies and processes significant volumes of transactions and data across multiple regions. Its main technical challenges include integrating a wide range of third-party services, maintaining stability and performance under high-load conditions, supporting complex scheduling and ride-pooling logic, and delivering precise cost management and reporting capabilities.

Strong backend engineering plays a key role in expanding the platform’s global reach, maintaining reliable performance, and ensuring a smooth experience for its users.
 

About the Role:

You will become part of a cross-functional engineering team responsible for developing and maintaining core backend services that have a direct impact on end users.

In this role, you will own the complete feature lifecycle—from reviewing business and product requirements and shaping technical solutions together with architects and product managers to implementation, testing, deployment, and production monitoring.

You will also act as the first line of support for the services you develop, proactively investigate performance and reliability issues, and work closely with other teams to maintain the stability of the overall system.

The position requires strong technical ownership, hands-on involvement in system architecture, and the ability to contribute to both engineering and product-level decisions. You will work remotely, with occasional in-person team gatherings, and will receive the equipment and working environment required to deliver measurable business value in a dynamic Agile setting.
 

Key Responsibilities:

• Own the end-to-end development of backend microservices, from technical design and implementation to deployment and production monitoring.
• Convert product requirements into scalable technical solutions, data models, and RESTful APIs.
• Build integrations with external transportation providers and internal systems to support reliable, real-time processes.
• Investigate and improve application performance and database queries in high-load environments.
• Suggest and implement architectural changes that improve scalability, resilience, and long-term maintainability.
• Support, refactor, and modernize existing services to strengthen code quality, automated test coverage, and observability.
• Work closely with cross-functional teams and support peers by sharing best practices in development, testing, and production operations.
• Take part in Agile activities such as backlog refinement and sprint planning to ensure technical delivery is aligned with business priorities.
   

Required Competence and Skills:

• 5+ years of professional backend development experience using Ruby.
• Proven experience building data-driven applications with relational databases such as PostgreSQL and NoSQL solutions such as Redis.
• Strong knowledge of RESTful API design and the HTTP protocol.
• Practical experience working within Agile/Scrum processes and delivering software iteratively.
• Solid experience writing unit tests and using automated testing practices.
• Strong spoken and written English communication skills.
• Ability to understand complex business requirements and translate them into effective technical solutions.
• Deep understanding of software architecture, high-load systems, and concurrency concepts.
   

Nice to Have:

• Experience developing applications in Golang.
• Strong knowledge of relational database performance optimization.
• Familiarity with gRPC and Protocol Buffers.
• Previous experience working with high-load distributed systems.
• Experience designing and developing concurrent applications.
   

Why Us:

- We provide 20 days of vacation leave per calendar year, in addition to the official national holidays of the country where you are based.

- We offer full accounting and legal support in every country where we operate.

- We follow a fully remote work model and provide a powerful workstation, as well as access to a co-working space when needed.

- We offer a highly competitive compensation package with annual performance and salary reviews.

Position is only for candidates located in Poland! 

Who we are:

Adaptiq is a technology hub specializing in building, scaling, and supporting R&D teams for high-end, fast-growing product companies in a wide range of industries.

About the Product:

Our client operates a cloud-based platform dedicated to corporate ground transportation management, addressing a multi-billion-dollar market. The solution aggregates multiple transportation providers—such as corporate fleets, ride-hailing services, taxi operators, and limousine networks—into a unified system that helps businesses streamline operations and reduce spend. It serves a significant share of the largest companies worldwide and handles high volumes of transactions and data across diverse geographies. The platform’s core challenges include integrating heterogeneous external services, maintaining reliability under high-load conditions, implementing advanced business logic for scheduling and pooling, and providing accurate cost control and reporting. Strong backend engineering is critical to scaling global coverage, ensuring performance, and delivering a seamless user experience.

About the Role:

You will join a cross-functional development team responsible for core backend services that directly impact end users. The role offers full ownership of feature delivery—from reviewing product requirements and defining technical designs alongside architects and product managers, through to coding, testing, deployment, and monitoring in production. You will serve as first-line support for your services, proactively identify and address reliability and performance issues, and collaborate with other teams to ensure end-to-end system integrity. This position demands technical leadership, a hands-on approach to system architecture, and the ability to influence both engineering and product decisions. You will work remotely with periodic team gatherings and receive the tools and environment needed to deliver tangible business impact in a fast-paced, agile setting.

Key Responsibilities:

• Lead end-to-end development of backend microservices, including design, implementation, deployment, and production monitoring.

• Translate product requirements into scalable technical designs, data models, and RESTful APIs.

• Integrate with external transportation providers and internal systems to enable reliable, real-time workflows.

• Analyze and optimize system performance and database queries under high-load scenarios.

• Propose and implement architectural improvements to enhance resilience, scalability, and maintainability.

• Maintain and refactor existing services to improve code quality, test coverage, and observability.

• Collaborate with cross-functional teams and mentor peers on best practices in coding, testing, and operations.

• Participate in agile ceremonies, including backlog grooming and sprint planning, to align deliverables with business priorities.

Required Competence and Skills:

• 5+ years of backend software development experience in Ruby.

• Proven experience designing and implementing data-driven applications using relational databases (e.g., PostgreSQL) and NoSQL stores (e.g., Redis).

• Solid understanding of RESTful API design principles and the HTTP protocol.

• Hands-on experience with Agile/Scrum methodologies and iterative delivery.

• Proficiency in writing unit tests and applying automated testing practices.

• Strong English communication skills, both verbal and written.

• Ability to understand complex business domains and translate needs into optimal technical solutions.

• Deep understanding of system architecture, high-load applications, and concurrency principles.

Nice to Have:

• Experience developing in Golang;
• Expertise in performance tuning of relational databases.

• Familiarity with gRPC and Protocol Buffers.

• Prior work on high-load, distributed systems.

• Background in building concurrent applications.

Why Us:

We provide 20 days of vacation leave per calendar year (plus official national holidays of a country you are based in).

We provide full accounting and legal support in all countries we operate.

We utilize a fully remote work model with a powerful workstation and co-working space in case you need it.

We offer a highly competitive package with yearly performance and compensation reviews.