Senior Backend Engineer (Ruby)

About the role

Perkbox is expanding its engineering team in Bulgaria and seeks a Senior Backend Engineer with deep Ruby on Rails expertise. You will own the backend services that power our mobile‑first, consumer‑facing applications, translating product goals into secure, scalable, and high‑performance solutions.

Key responsibilities

• Define and evolve the technical vision for Ruby on Rails applications and related backend services.
• Design, build, and maintain robust RESTful and GraphQL APIs with secure authentication and authorization.
• Implement scalable AWS architectures using RDS, Lambda, Kubernetes, and related services.
• Identify performance bottlenecks, optimise API speed, and devise effective caching and database strategies.
• Establish CI/CD pipelines, coding standards, and code‑review practices.
• Embed security‑by‑default throughout the SDLC, ensuring compliance with ISO 27001 and SOC2.
• Collaborate with frontend teams, product managers, and stakeholders to deliver impactful features.
• Lead incident response, root‑cause analysis, and preventive engineering.

Required profile

• 4+ years of professional experience with Ruby on Rails.
• Strong understanding of MVC architecture and JavaScript/TypeScript.
• Proven ability to design and ship complex backend systems in a fast‑paced environment.
• Experience working with AI‑powered workflows and automation is a plus.

Required skills

• Ruby on Rails
• JavaScript / TypeScript
• PostgreSQL / MySQL
• AWS (RDS, Lambda, Kubernetes)
• GraphQL
• RESTful API design
• RSpec, Git, unit testing, mocking
• CI/CD pipelines
• AI agents and automation

What we offer

• Remote work for candidates residing in Bulgaria.
• Gross annual salary €60,000‑€65,000, based on experience.
• Opportunity to shape architecture and mentor engineers.
• Culture focused on wellbeing, impact, and growth.