Senior Backend Engineer – Ruby on Rails

Gravitas Recruitment Group (Global) Ltd; Greater London; Hybrid; GBP 90,000 - 100,000; Full time

Benefits offered by this job

30 days annual leave + bank holidays

£1,000 annual learning & development

Private medical insurance

Pension contribution matched up to 6%

MacBook Pro

Highly flexible hybrid working

Job summary

Gravitas Recruitment Group (Global) Ltd is seeking a Senior Backend Engineer in London to own complex backend problems and influence technical direction. The role is hands-on and not a lead position, with opportunities to work across Ruby on Rails, PostgreSQL, API design, and related technologies.

You will join a high-performing team in a hybrid setup (1 day in office / 4 days from home) and help improve engineering practices, mentorship, and product impact.

Qualifications

• Strong commercial experience building production systems with Ruby on Rails.

Responsibilities

• Build and scale production Ruby on Rails applications.
• Design and maintain robust internal and external APIs.
• Work with PostgreSQL including data modelling, queries and performance.
• Background processing using Sidekiq.
• Improve testing and engineering standards.
• Make pragmatic architectural decisions for long-term maintainability.
• Collaborate closely with Product to understand customer impact.
• Own problems end-to-end and mentor teammates.

Skills

Ruby on Rails

PostgreSQL

API design

RSpec

Code ownership

Tools

RSpec

PostgreSQL

Job description

£90,000 – £100,000 | London | Hybrid – 1 day in office / 4 days from home

We’re partnering with a fast-growing, product-led technology business to hire a Senior Backend Engineer into a high-performing engineering team.

This is a genuinely hands-on Senior IC role. It isn’t a Team Lead position and there’s no expectation to move away from coding. Instead, we’re looking for an experienced engineer who can take ownership of complex backend problems, influence technical direction and make the engineers around them better.

The business is continuing to scale its core platform, with Ruby on Rails sitting at the heart of the backend. As the product and customer base have grown, so have the engineering challenges around architecture, scalability, maintainability and where business logic should live.

You’ll work on challenges including:

• Building and scaling production Ruby on Rails applications
• Evolving and improving an established Rails codebase
• Designing and maintaining robust internal and external APIs
• Working extensively with PostgreSQL, including data modelling, queries and performance
• Background processing using Sidekiq
• Improving testing, reliability and overall engineering standards
• Making pragmatic architectural decisions with long-term maintainability in mind
• Working closely with Product to understand the customer impact behind technical decisions
• Owning problems end-to-end rather than simply completing tickets
• Pairing, mentoring and sharing knowledge across the engineering team

The wider environment also includes React / Next.js / TypeScript, Redis and AWS, so engineers who are comfortable occasionally moving beyond the backend will have plenty of opportunity to do so.

What we're looking for

You’ll have strong commercial experience building production systems with Ruby and Ruby on Rails, but this isn't simply about counting years on a CV.

We’re particularly interested in engineers who can demonstrate:

• Good PostgreSQL and SQL knowledge
• Experience designing and scaling APIs and backend services
• Strong testing practices, ideally including RSpec
• An understanding of architecture, scalability and maintainable software design
• Experience taking meaningful technical ownership
• Strong collaboration with Product and other engineers
• A pragmatic approach to solving problems rather than over-engineering them

Just as importantly, we’re looking for a low-ego force multiplier.

That could mean improving engineering practices, mentoring through pairing, de-siloing knowledge, improving code-review culture, introducing better testing or simply helping the people around you become stronger engineers.

You don't need a Lead title to demonstrate leadership.

Location: Central London

Hybrid: 1 day per week in the office / 4 days working from home

Benefits include:

• 30 days' annual leave + bank holidays
• £1,000 annual learning & development budget
• Private medical insurance
• Pension contribution matched up to 6%
• MacBook Pro
• Highly flexible hybrid working

The process is designed to assess both technical ability and how you work with other engineers:

The technical stages are as much about how you think, the decisions you make and the trade-offs you consider as simply reaching the correct answer.

If you're an experienced Ruby engineer who wants to remain close to the code, solve meaningful scaling problems and have genuine influence over both the product and engineering culture, I'd love to hear from you.