Senior Java Developer

London Stock Exchange; Greater London; On-site; GBP 110,000 - 150,000; Full time

Job summary

London Stock Exchange seeks a Senior Lead Scala Engineer to deliver a critical market-infrastructure service on the Equities platform. You will design and maintain scalable backend services in Scala, with a focus on AWS cloud-native development.

Reporting to the Senior Technical Delivery Engineer, you will shape technical direction and uphold engineering excellence. As a senior contributor, you will drive best practices, build robust services, and collaborate across squads to ensure reliable

Qualifications

• Proven experience delivering enterprise-grade Scala applications in production environments.
• Strong background in building scalable, resilient backend services.
• Hands-on experience with cloud-native development and AWS services.

Responsibilities

• Design, implement, and maintain backend services written in Scala.
• Contribute to technical direction and engineering standards for the Equities platform.
• Collaborate across teams to ensure high-quality, observable, and scalable solutions.

Skills

Scala

Akka

Play Framework

Functional programming

OO programming

Kafka

Docker

Kubernetes

Postgres

AWS

Tools

GitLab

JUnit

Cucumber

Gherkin

PACT

Test Containers

Flyway

Liquibase

AWS S3

Job description

• The Senior lead Scala Engineer will play a key role in the engineering and delivery of a critical market-infrastructure service within the Equities platform, with a strong focus on AWS cloud-native development
• Reporting directly to the Senior Technical Delivery Engineer, Post Trade, the successful candidate will be responsible for designing, implementing, and maintaining performant, resilient, and scalable backend services built predominantly in Scala
• As a senior member of the engineering team, this individual will help shape technical direction, contribute to best-in-class engineering standards, and actively support the continued growth and evolution of the business
• This exciting opportunity requires a candidate to take Pride in their work and Ownership of their work. Have excellent engineering skills, communication skills, can-do behaviour and highly collaborative. Always positively encouraging the team
• A strong focus on engineering excellence and coding, adopting an open and hands-on approach to problem-solving and delivery. Engage deeply in technical design and implementation to ensure solutions are robust, scalable, and aligned with industry best practices
• Actively contribute to all stages of the product engineering life cycle - solutioning, design, coding, and testing, while promoting collaboration and transparency within the team to drive high-quality outcomes
• Demonstrate ownership and pride in work, proactively taking on new responsibilities aligned with product engineering needs. Embrace and apply LSEG engineering principles, diving deep technically to build with purpose and foster excellence within the team through open collaboration
• Create an environment of engagement, challenge, and constructive questioning, ensuring trust and respect are maintained and a strong one-team mentality is upheld

• Working knowledge of event/message brokers such as Kafka and MQ
• Expertise in building and maintaining DevOps pipelines, ideally with GitLab
• Proficient in shift-left testing using tools like JUnit, Cucumber, Gherkin, PACT, and Test Containers
• Experience with containerization and orchestration using Docker and Kubernetes
• Strong understanding of microservices design, including pitfalls and best practices
• Knowledge of Domain-Driven Design (DDD) and event-driven architecture principles
• Skilled in event-driven patterns for efficient and robust communication
• Akka - for building concurrent, distributed, and resilient message-driven systems
• Deep practical expertise with Scala, including key frameworks and libraries such as:
• Strong proficiency in both functional and object-oriented programming paradigms, with the ability to apply the right approach to deliver robust, maintainable solutions
• Play Framework - for developing scalable, high-performance web applications
• Strong understanding of data structures, algorithms, concurrency, and multi-threading, with the ability to design efficient and scalable solutions for high-throughput systems
• Cats / Scalaz - for implementing advanced functional programming abstractions and patterns
• Proven experience delivering enterprise-grade Scala applications in production environments, with a focus on quality, resilience, performance, and observability
• Basic understanding of cloud networking concepts
• Strong SQL knowledge with experience in relational databases such as Postgres
• Familiarity with database version control tools like Flyway and Liquibase
• Working knowledge of object storage solutions, e.g., AWS S3
• Cloud Architecture
• Hands-on use of cloud-based services such as AWS Aurora, MSK, S3, and IAM
• Experience working with major public cloud platforms, preferably AWS
• Experience working within Scrum and Kanban frameworks
• You have some experience of writing applications using Java
• Strong understanding and commitment to the ethos of agile working
• You have developed Web applications using ReactJS
• Proven collaboration with cross-functional teams in scaled agile environments
• Active participation in sprint ceremonies, including Product Backlog Refinement