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 approachDesirable / 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 environmentAbout 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