Senior Backend Developer
Senior Backend Developer - Ruby/Elixir
Location: London - Remote
Outside IR35
Immediate starter.
We're supporting a technology business undertaking a major modernization programme and are looking for a Senior Backend Developer to drive a large-scale refactoring initiative across a complex, multi-service platform.
This is a hands-on role for someone who enjoys untangling Legacy code, improving architecture, and leaving systems in a measurably better state than they found them. You'll combine deep engineering capability with pragmatic technical leadership to deliver safer, faster, and more scalable services.
What you'll be doing:Lead end-to-end refactoring across multiple Back End technology stacks
Redesign and modernise the messaging and event architecture
Improve database performance, reliability, and schema design
Reduce technical debt while keeping business disruption to a minimum
Define and embed engineering standards and maintainability practices
Support and mentor engineers working alongside you
What you'll need to bring:
Backend engineering
Strong commercial experience with Elixir including OTP, GenServers and Phoenix
Expert use of Ruby
Roughly 5+ years working across both ecosystems
Data layer
Advanced optimisation and performance tuning in MySQL
Strong knowledge of PostgreSQL, including complex queries and administration
Confidence managing migrations and schema evolution
Messaging & distributed systems
Strong experience with Google Cloud Pub/Sub or comparable technologies such as RabbitMQ, Apache Kafka, or Amazon SQS
Practical understanding of event-driven patterns, ordering, retries, and delivery guarantees
Experience that will set you apart:
7+ years in Back End engineering roles
Proven ownership of significant refactoring or modernisation programmes
Background in microservices and distributed architectures
Track record improving scalability and performance in production systems
Experience moving Legacy estates toward modern designs
We are an equal opportunities employer and welcome applications from all suitably qualified persons regardless of their race, sex, disability, religion/belief, sexual orientation, or age.