Senior Ruby Backend Engineer - Hybrid, API & Scale

Zuno; Greater London; Hybrid; GBP 90,000 - 130,000; Full time

Benefits offered by this job

30 days annual leave + bank holidays

Private medical cover

4x salary Death in Service

Maternity/Paternity pay after a year

£1000 annual training budget

Pension matched up to 6%

Flexible working times and location

Company MacBook Pro

Team lunches & events

Job summary

Zuno is seeking a Senior Backend Engineer to define the architectural direction of server-side logic and ensure scalable data models. You will design and optimise high-performance APIs using Ruby on Rails, collaborating with Product Managers to shape roadmaps and ensure feasibility from the outset.

You will mentor junior engineers, review code, and contribute to maintaining high-quality engineering practices.

Qualifications

• 5+ years of professional experience in backend development.
• Strong expertise in Ruby and Ruby on Rails, including metaprogramming and Rails internals.
• Proven ability to design complex, normalised database schemas and write performant SQL (PostgreSQL).
• Experience designing and maintaining versioned, documented RESTful APIs.
• Experience writing automated tests with RSpec (integration & request specs).
• Experience working in Agile development environments.
• Proficiency with Git and modern PR/code-review workflows.

Responsibilities

• Design, build, and maintain robust, scalable backend features in Ruby on Rails.
• Architect and document performant RESTful APIs for React/Next.js frontend.
• Lead technical discussions on system design and database schema planning.
• Identify and resolve performance bottlenecks, optimise SQL and caching (Redis).
• Mentor junior engineers and review teammates' code to ensure quality.
• Own complex backend features from concept to deployment, manage technical debt.

Skills

Backend development

Ruby & Rails

SQL & PostgreSQL

OOAD & design patterns

RESTful APIs

Testing with RSpec

Agile

Git & PR/workflows

Problem solving

Communication

Job description

Zuno is seeking a Senior Backend Engineer to define the architectural direction of server-side logic and ensure scalable data models. You will design and optimise high-performance APIs using Ruby on Rails, collaborating with Product Managers to shape roadmaps and ensure feasibility from the outset.

You will mentor junior engineers, review code, and contribute to maintaining high-quality engineering practices.