Senior Backend Engineer - Ruby on Rails

Ersilia; Barcelona; A distancia; EUR 65.000 - 90.000; Jornada completa

Descripción de la vacante

Ersilia is seeking a senior backend engineer to own critical systems and contribute to the roadmap. You will implement code, review it, test rigorously, and ensure reliability, performance, and correctness across production environments.

Work autonomously with high ownership, collaborating with engineering and product teams while balancing risk and business needs. English proficiency is a must for global collaboration.

Formación

• 5+ years of experience building and maintaining production systems as a backend engineer.
• Strong experience with Ruby on Rails.
• AI-first mindset using tools like Cursor, Claude Code, Codex in daily workflow.
• Experience owning business-critical systems.
• Advanced level of English.

Responsabilidades

• Hands-on code implementation, code reviews, testing.
• Ensure reliability, performance and correctness.
• Diagnose and resolve complex production issues.
• Collaborate with other engineering & Product teams.
• Make pragmatic decisions balancing risk, maintainability and business needs.
• Improve code quality and internal structure where possible.

Conocimientos

Backend development

Problem solving

Autonomy

Herramientas

Ruby on Rails

PostgreSQL

Redis

Tailwind

Cursor

Claude Code

Codex

Descripción del empleo

You will take ownership of a backend system that is critical to the company and our customers. You will have the opportunity to help define our roadmap and find the best technical solutions. You will also have time to run some experiments and bring new ideas to the table.

Your responsibilities:

• Hands-on code implementation, code reviews, testing
• Ensure reliability, performance and correctness.
• Diagnose and resolve complex production issues.
• Collaboration with other engineering & Product teams.
• Make pragmatic decisions balancing risk, maintainability, and business needs.
• Improve code quality and internal structure where possible.

What we are looking for:

• 5 years plus experience building and maintaining production systems as backend engineer
• Strong experience with Ruby on Rails
• AI-first mindset using tools like Cursor, Claude Code, Codex, in your daily workflow
• Working on large-scale products
• Experience owning systems that are business critical.
• Methodical approach to debugging and problem solving.
• Comfortable working autonomously with high ownership.
• Advanced level of English.

Tech Stack:

• Language & Platform: Ruby
• Data: PostgreSQL or Redis
• Infrastructure: Tailwind

Location:

Barcelona, Spain > or Fully remote within a +/- 4hrs CET