Functional Programming Engineer

Job DescriptionFunctional Programming EngineerLocation: LondonWorking Model: Hybrid - 3 days per week in the office, with flexibility for the candidate to choose which 3 days they work onsiteContract: 6-month rolling contract, with a further 6-month potential extensionRate: Open to discussion based on the candidate’s expectations and experience About the OpportunityWe are working with a leading global banking organisation on a high-profile Front Office technology programme within its Investment Banking / Capital Markets environment.We are looking for a genuinely senior, hands-on engineer to join a high-calibre engineering team developing and enhancing a business-critical platform used by Front Office teams. The team is particularly interested in engineers with a strong functional programming background and a solid understanding of modern software design principles. Kotlin experience is highly relevant, but the team is also open to engineers with strong functional programming

experience in languages such as Scala or Clojure who are willing and able to embrace Kotlin. This is a senior engineering role requiring strong technical depth, experience with Event Sourcing and Event-Driven Architecture, and the ability to work directly with business stakeholders. Key Requirements Strong functional programming experience and understanding of functional programming principles Strong commercial experience with Kotlin, Scala, Clojure or another functional programming language Willingness and ability to work with Kotlin where it is not already your primary language Deep hands-on experience with Event Sourcing Strong understanding of Event-Driven Architecture Experience with CQRS and modern distributed systems Senior/VP-level engineering experience Experience working directly with Front Office / business stakeholders Strong experience with TDD, XP practices and collaborative engineering Experience with pair and/or mob programming Cloud experience, ideally GCP, with technologies such as GKE / Cloud Run Strong backend engineering experience building reliable, scalable and maintainable systems What You’ll Be Doing Design, build and evolve highly reliable backend services Develop systems using Event Sourcing and Event-Driven Architecture Apply functional programming principles to software design and implementation Work with Kotlin and contribute to a modern, highly collaborative engineering environment Work closely with Front Office users and business stakeholders to understand requirements and shape technical solutions Contribute to technical design and architectural decisions Develop clean, maintainable and well-tested code using TDD Work collaboratively through pair programming, mob programming and other XP practices Support production systems where reliability, correctness and availability are critical Help shape the engineering approach and share technical expertise across the wider team What We’re Looking ForWe are particularly interested in senior engineers who bring strong functional programming expertise, rather than simply looking for candidates based on a specific technology stack.Relevant backgrounds could include: Kotlin with strong functional programming experience Scala / Scala-based backend engineering Clojure Other functional programming languages or environments, where the candidate has strong transferable engineering principlesThe ability to demonstrate genuine Event Sourcing experience, strong engineering fundamentals and the ability to engage directly with business users will be particularly important. Key Skills Functional Programming | Kotlin | Scala | Clojure | Event Sourcing | Event-Driven Architecture | CQRS | Backend Engineering | TDD | XP | Pair Programming | Mob Programming | GCP | Front Office | Investment Banking | Capital Markets This is a top-tier senior engineering opportunity for someone who combines strong technical depth with functional programming expertise, modern distributed-systems experience and the ability to work closely with Front Office stakeholders.