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.