Senior Ruby On Rails Engineer

Senior Ruby On Rails Engineer / Tech Lead

Location: London (Hybrid – 2 days per week onsite)
Salary: Up to £100,000 (DOE)

The opportunity:
We’re looking for a Senior Ruby Engineer / Tech Lead to join a growing technology business building large-scale operational SaaS platforms used within complex, real-world environments.

This is a hands-on senior engineering role with a clear pathway into broader technical leadership responsibilities. It would suit someone who enjoys solving complex backend challenges while also taking ownership of delivery, technical direction, and team support.

You’ll play a key role in scaling a modern Rails-based platform that supports high-volume transactional workflows, integrations with external systems, and mission-critical operational processes.

Working closely with the Director of Engineering, you’ll help shape backend architecture, improve delivery processes, support customer onboarding initiatives, and act as a senior technical escalation point across the platform.

The business operates within a fast-paced product environment where reliability, scalability, and delivery quality are critical. The culture is collaborative, pragmatic, and ownership-driven, with a strong focus on autonomy, accountability, and continuous improvement.

What you’ll be doing:

As a Senior Ruby Engineer / Tech Lead, you’ll take ownership of backend delivery across key product areas while remaining heavily involved in hands-on engineering.

Key responsibilities include:

• Leading backend development across a large-scale Rails application
• Owning technical direction and contributing to architectural decisions
• Designing, building, and maintaining scalable backend services and APIs
• Supporting platform scalability, reliability, and maintainability
• Improving and refactoring existing backend functionality to reduce technical debt
• Optimising background job processing and asynchronous workflows
• Supporting integrations with external third-party systems and APIs
• Leading delivery planning, estimation, and technical scoping activities
• Acting as a senior escalation point for technical and delivery-related challenges
• Collaborating closely with product, engineering, and stakeholder teams
• Supporting sprint planning, Agile ceremonies, and delivery processes
• Mentoring and supporting engineers through technical guidance and collaboration
• Helping improve engineering standards, processes, and team effectiveness

 
What we’re looking for:
Essential experience:

• Strong commercial experience with Ruby on Rails within production environments
• Experience building and maintaining scalable backend systems and APIs
• Strong understanding of Rails monolith architecture
• Experience with PostgreSQL, Redis, and Sidekiq
• Experience working with AWS-based infrastructure
• Experience using Docker within development or production environments
• Strong debugging and problem-solving capabilities
• Excellent communication and stakeholder management skills
• Ability to explain technical concepts clearly to both technical and non-technical audiences
• Strong ownership mentality with a pragmatic engineering approach

Desirable / bonus experience:

• Experience leading Agile ceremonies or delivery processes
• Experience scoping technical work and contributing to estimation activities
• Experience working with Kubernetes-based deployments
• Experience integrating third-party platforms and APIs
• Experience within B2B SaaS or operational platform environments
• Experience supporting live production systems at scale
• Experience mentoring or supporting engineers within a team environment

About you:

• You’re a hands-on engineer who enjoys solving complex technical problems
• You’re comfortable balancing technical leadership with day-to-day delivery
• You enjoy mentoring and supporting other developers
• You care about scalability, maintainability, and engineering quality
• You communicate clearly and collaborate well across technical and non-technical teams
• You’re proactive, adaptable, and comfortable taking ownership
• You thrive in fast-moving environments where technology has real operational impact

Core technology stack:

• Ruby
• Ruby on Rails
• PostgreSQL
• Redis
• Sidekiq
• REST APIs
• AWS
• Docker
• Kubernetes
• Jira, Slack