Senior Java / Kotlin Engineer - Prime Brokerage

JUXT; Greater London; On-site; GBP 70,000 - 110,000; Full time

Job summary

JUXT in London is seeking a senior engineer to join our embedded team within Prime Brokerage. You will own data-intensive systems, transform and modernise legacy components, and deliver regulatory and client reporting work with Kotlin and Java.

You will build pipelines between SQL Server, MongoDB, Kafka/EMS, and downstream consumers, optimise performance, and collaborate with SMEs across time zones in a regulated banking environment.

Qualifications

• Strong Java and Kotlin experience with data-intensive systems.
• Heavy SQL Server database expertise and performance analysis.
• Experience with MongoDB, Kafka and REST APIs.
• Containerisation/orchestration with OpenShift/Kubernetes.
• Focus on observability, testing and end-to-end quality.

Responsibilities

• Drive delivery of regulatory and client reporting work within Prime Brokerage.
• Build and maintain data transformation pipelines between SQL Server, MongoDB, Kafka/EMS and downstream consumers.
• Engage with upstream data providers, downstream consumers and SMEs to gather requirements.
• Modernise the stack by transforming large stored procedures into Kotlin services.
• Analyse database performance and optimize reporting accuracy.
• Help with platform modernisation, e.g. scheduling migrations to Kubernetes/OpenShift.

Skills

Java

Kotlin

SQL Server

MongoDB

Kafka

REST APIs

OpenShift

Kubernetes

Observability

Testing

BigData

AI coding

Tools

SQL Server

OpenShift

Job description

We’re looking for a senior engineer to join us working in in our embedded team within Prime Brokerage, the area of the bank that works with hedge funds and large institutional clients. You’ll work hands-on to build data-intensive systems with huge scale. The role carries real ownership and you will help develop the regulatory and client reporting book of work whilst modernising the systems that deliver it.

The Client Reporting platform sits at the heart of Prime Brokerage, taking client data in from upstream systems, transforming and mastering it, and delivering reports and data feeds to clients and to many downstream systems across the bank. You will work across new and existing Kotlin and Java applications, with new development primarily in Kotlin. Large databases and messaging at scale will be a significant part of the role.

You’ll work on big banking systems, absorb the domain, understand why systems are the way they are, and improve and evolve them incrementally and safely. We’re looking for engineers with excellent taste.

What you will do

• Drive delivery of the regulatory and client reporting book of work, where change is constant and deadlines can be market- or regulator-driven.
• Build and maintain data transformation pipelines moving data between SQL Server, MongoDB, Kafka/EMS, and downstream consumers.
• Engage directly with upstream data providers, downstream consumers, and business SMEs to understand requirements and the history of the systems.
• Modernise the existing stack: a flagship example is transforming large SQL Server stored procedures into well-tested Kotlin services.
• Dig into performance and correctness at the database level - you should be comfortable reasoning about things like logical vs physical reads when a report is slow.
• Help with platform modernisation, for example migrating scheduling from legacy tech (Autosys) onto Kubernetes/OpenShift.

Essential skills and experience

• Strong Java and Kotlin. (C# exposure is a plus but not essential).
• Heavy database experience: expert SQL and relational modelling on SQL Server, including performance analysis and working with stored-procedures.
• MongoDB (documents and collections, aggregation/map-reduce).
• Messaging and streaming: Kafka, Solace, Tibco EMS or similar.
• Building and consuming REST APIs and RPC services.
• Containers and orchestration with OpenShift/Kubernetes.
• Focus on observability: ELK, OpenTelemetry, Grafana, Prometheus.
• Focus on automated, shift-left testing: integration tests, building harnesses, valuable end-to-end and regression testing.
• A track record of work on large banking or reporting systems: understanding a complex domain, understanding the history of a system, and collaborating with disparate teams.
• Comfortable operating within the constraints of a large regulated bank - VDIs, change control, release processes, and security review.
• Prime Brokerage or wider markets/securities domain experience are useful.
• Exposure to BigData cloud tech such as Starburst/Trino and Snowflake.
• Experience developing/migrating batch/scheduled workloads at scale.
• Experience modernising legacy systems incrementally - wrapping tests around untested code, then refactoring with confidence.
• Practical/effective use of AI coding assistants (e.g. Copilot with recent models).

What kind of person thrives here

• Pragmatic and delivery-focused: you balance modernisation ambitions against the need to ship the book of work month by month.
• Self-starting in ambiguous environments: requirements often live in people’s heads and in the systems themselves, and you go and find the answers.
• A strong communicator who builds relationships with SMEs, upstream teams, and stakeholders across time zones.
• Resilient to the realities of banking: restrictions, approvals, and legacy constraints are navigated, not fought.