Senior Full Stack Engineer - Ruby on Rails & ReactJS

About Checkmate

Checkmate is a restaurant technology solution provider that has continually evolved over time. We started in 2017 by integrating 3rd party platforms to the POS systems of restaurants. At that time, there were multiple 3rd party platforms like GrubHub, UberEats, DoorDash, Postmates, Caviar, and even Amazon!

This was the photograph that started it all!

We have since then continually evolved to add multiple products to our portfolio, the primary ones being first party ordering solutions like web and app ordering, kiosks and catering. We have now recently moved into three new exciting products: Digital Menu Boards, Phone Ordering AI and Drive thru AI. We form a very core part of the restaurant technology ecosystem, and are continually adding more and more digital solutions for the restaurant brands to increase their sales.

Our revolutionary enterprise menu management system, Everyware, truly unlocks the potential of menus and how it can be customized for each individual digital channel. As you can see, this is a company that continually evolves and adapts and today we are powering digital ordering solutions for some of the largest brands in the world.

We have been called the "north star of vendors" as we truly believe that technology is just a method by which we service the customers, it does not form the entirety of it. Service is a big component of what we provide to our customers, which is inherently believed by every single team member here. We are doing a lot of exciting things, including application of AI in our products and systems, using experimentation at scale to determine what works for our clients and ML to analyze and productize the massive amount of data we have. Each individual here makes a difference and has a valuable contribution. Key traits here are ownership and drive. Join us if you think you have them.

We’re looking for an experienced Senior Full Stack Engineer (Ruby on Rails, React.js) to join our engineering team and take ownership of quality, reliability, and long-term maintainability across our core platform. This is not a feature-delivery role. You will be working within a pod focused on bug management, technical debt reduction, and system health—improving the stability and performance of a large, high-traffic production system that supports our web and mobile experiences.

This is a highly impactful role for someone who finds satisfaction in making complex, established systems more reliable, more understandable, and easier to work in—not someone looking primarily to ship new features. You will work closely with engineers, product managers, and stakeholders to identify, prioritize, and resolve systemic issues across the full stack.

As a key member of our engineering team, you’ll design, develop, and maintain critical services that support our products and customers:

• System Health & Bug Resolution
• Investigate, diagnose, and resolve complex bugs across the full stack—from database queries and Rails backend logic to React frontend behavior.
• Own production incidents end-to-end: from detection and root cause analysis through resolution, post-mortem, and follow-up improvements to prevent recurrence.
• Use observability and monitoring tools (e.g., Datadog, Sentry, New Relic) to proactively identify issues before they reach customers.
• Technical Debt Reduction
• Identify, prioritize, and systematically reduce technical debt across the codebase in collaboration with engineering leadership.
• Refactor and improve existing systems with a focus on modularity, maintainability, and long-term scalability—without unnecessary rewrites.
• Communicate the impact of tech debt in terms meaningful to product and business stakeholders, and build buy-in for remediation work.
• Backend Development & Core Services
• Design, develop, and maintain critical backend services and application logic using Ruby on Rails, ensuring high reliability, performance, and security.
• Design and optimize RESTful or GraphQL APIs for efficient, reliable data access.
• Manage asynchronous processing and background job pipelines (e.g., Sidekiq) for scalable task execution.
• Database Management & Performance
• Write, tune, and optimize complex SQL queries across PostgreSQL/MySQL for performance and scalability.
• Design and maintain relational database schemas with long-term maintainability in mind.
• Profile and resolve N+1 queries, missing indexes, and other database-layer performance issues.
• Frontend Development
• Build and maintain React.js components and application logic, ensuring responsiveness, cross-browser compatibility, and performance.
• Refactor legacy frontend code—including migrating class components to functional components—while preserving existing behavior.
• Diagnose and resolve frontend performance issues including rendering bottlenecks, bundle size, and state management problems.
• Architecture & Code Quality
• Lead architecture and design decisions for refactored systems, balancing pragmatism with long-term quality.
• Enforce code quality through best practices, comprehensive automated testing, and active participation in code reviews.
• Contribute to improving CI/CD pipelines, deployment workflows, and automated testing infrastructure

• 7+ years of professional full-stack experience with Ruby on Rails and React.js in production environments.
• Demonstrated experience working in a large, established, complex codebase you did not build from scratch—owning components, navigating unfamiliar systems, and making targeted improvements.
• Strong SQL proficiency: custom query writing, schema design, query optimization, and ORM usage (ActiveRecord).
• Hands-on experience with asynchronous processing and background job frameworks (e.g., Sidekiq, Delayed Job).
• Proven experience diagnosing and resolving production bugs using observability tooling (Datadog, Sentry, New Relic, or equivalent).
• Experience with high-performance, high-traffic consumer-facing applications—ideally in e-commerce, restaurant tech, or retail.
• Expert proficiency in React.js, JavaScript (ES6+), and TypeScript, including hooks, state management (Redux, Context API), and component design.
• Solid understanding of CI/CD pipelines, Git-based version control, and automated testing frameworks.
• Excellent written and verbal communication skills. Must be a self-starter comfortable working independently with minimal supervision.
• BSc in Computer Science, Engineering, or a relevant field—or equivalent professional experience.
• Must be comfortable working in US hours at least till 5 pm EST.

Nice-to-Haves

• Technical lead or architecture lead experience.
• Experience with AWS ecosystem services (EC2, ECS, RDS, S3, EKS) and cloud-based scalability considerations.
• Familiarity with containerization (Docker) and orchestration (Kubernetes).
• Experience with Next.js or other server-side rendering frameworks.
• Familiarity with performance profiling, web optimization techniques, and advanced caching strategies (e.g., Redis).
• Experience with design tools such as Figma or Sketch.
• Background working in Agile or Scrum environments.