Senior Software Engineer, CalcGraphs - Vice President

Citi; Greater London; On-site; GBP 70,000 - 90,000; Full time

Job summary

A leading financial institution in Greater London is seeking a Senior Engineer for the role of Applications Development Technology Lead Analyst. This position involves designing and maintaining a high-performance calculation engine within a distributed environment. Ideal candidates will have extensive experience with Java frameworks, distributed systems, and cloud platforms. Responsibilities include enhancing the calculation engine and mentoring junior developers. The role offers opportunities to optimize large-scale financial calculations and ensure robust platform operations.

Qualifications

• Multiple years professional software development experience with Java.
• Solid experience with Java frameworks (e.g., Spring, Spring Boot, Quarkus).
• Experience designing and maintaining large-scale distributed systems.
• Strong understanding of object-oriented programming and design patterns.
• Familiar with unit testing and integration testing frameworks.

Responsibilities

• Design, build, and maintain the calculation engine for the XiP platform.
• Mentor mid-level developers and oversee their work.
• Lead enhancements to the Risk Calculation Engine.
• Monitor and optimize the execution of large-scale risk calculations.
• Coordinate strategic changes to scale the engine.

Skills

Java

Java Spring Boot

RESTful API

Object-oriented programming

NoSQL databases

Cloud platforms

Containerisation

Agile/Scrum

Unit testing

Python

Education

Bachelor's or Master's degree in Computer Science

Job description

Team Overview

XiP is building a next‑generation cross‑asset calculation system for Citi trading desks and enterprise users in the largest global financial markets and exchanges in New York, London, and other major financial hubs.

Our team owns multiple Java Spring Boot Services that execute, partition, and track quantitative risk graphs/trades in a distributed environment. These graphs can fail due to their complexity and our system must adapt quickly to these failures to provide a seamless experience for clients.

XiP Compute Services are deployed onto OpenShift and Amazon’s Elastic Kubernetes Service (EKS). An important initiative in 2025 will be onboarding Google’s Kubernetes Engine to further expand our coverage. Our system scales on‑demand, and we can run up to tens of thousands of replicas of our services across all asset classes.

Role Overview

We are seeking a Senior Engineer to fill the role of “Applications Development Technology Lead Analyst” on the XiNG large‑scale distributed calculation platform (XiP).

In this role you will design, build, and maintain the calculation engine at the heart of the XiP platform. This engine is responsible for c. 0.5 billion risk & suitability calculations at Citi every day. A single customer run compresses 17 million minutes of compute into a single 90‑minute execution.

Run on hundreds of thousands of pods across the entire XiP platform every day, this calculation engine is both highly performant and rapidly changing to support new scenarios, technologies, and infrastructure.

As an engineer working on the calculation engine, you will work closely with software engineers, DevOps, and our customers to ensure reliable, secure, and scalable operations of our platform.

Responsibilities

• Take part of the shared responsibility for the long‑term strategic direction of the XiP Calculation Engine: Apply your experience and skills to develop the future versions of the calculation engine. This means making it faster, utilizing resources better, and scaling to even greater sizes. This means adding new features without impacting performance of the platform in an undesirable manner – small changes multiplied by millions of calculations have a high cost. This means solving hard problems like transferring small amounts of data to a huge number of machines.
• Serve as advisor or coach to team members, allocating and overseeing work: Mentor and guide mid‑level developers, providing technical advice, code reviews, and career development support. Allocate tasks based on skill sets and project priorities, ensuring balanced workloads and timely delivery. Foster a collaborative and growth‑oriented team environment, encouraging best practices and continuous learning.
• Implement changes and improvements to Citi’s Risk Calculation Engine, including analyzing and designing improvements to the distribution mechanisms of the engine which regularly parallelises 250,000 hours of compute into a single 90‑minute execution: Lead the design, development, and implementation of enhancements to the Risk Calculation Engine, focusing on optimizing its distribution mechanisms. Analyze current parallelisation strategies and identify opportunities to further improve efficiency, scalability, and throughput.
• Operationally support the optimisation of Risk calculations by examining and providing SME level insight into the distributed execution of extremely large calculations: Monitor and analyse the distributed execution of large‑scale risk calculations, identifying performance bottlenecks and inefficiencies. Provide subject‑matter expertise to guide operational improvements, leveraging deep technical knowledge to recommend and implement optimisations that enhance calculation speed and resource utilisation.
• Plan, coordinate, and execute strategic changes to the engine to reach the next scaling milestone: Develop and manage strategic initiatives aimed at scaling the Risk Calculation Engine to meet future business demands. Coordinate with stakeholders to ensure that all scaling efforts are aligned with customer needs.
• Provide specialised customer support to optimise and improve large, distributed calculations: Act as a primary point of contact for clients to address issues and optimise inefficiencies that arise during distributed workload execution.

Qualifications

• Multiple years professional software development experience with Java.
• Solid experience with Java frameworks (e.g., Spring, Spring Boot, Quarkus).
• Experience designing, building, and maintaining large‑scale, distributed systems.
• Experience with RESTful API design and implementation.
• Strong understanding of object‑oriented programming and design patterns.
• Exposure to NoSQL databases (e.g., MongoDB, Cassandra) is a plus.
• Exposure to cloud platforms (e.g., AWS, Azure, GCP) and containerisation (e.g., Docker, Kubernetes) is desirable.
• Experience with unit testing, integration testing, and test automation frameworks (e.g., JUnit, Mockito).
• Experience working in Agile/Scrum development environments.
• Practical experience with Python for scripting, automation, or data processing tasks.
• Experience with CI/CD pipelines and DevOps practices is a plus.

Education

Bachelor’s or Master’s degree in Computer Science, Engineering, or a related field.

Job Family Group: Technology

Job Family: Applications Development

Time Type: Full time

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