Principal Engineer

lseg; Greater London; On-site; GBP 120,000 - 180,000; Full time

Job summary

London Stock Exchange Group is seeking a Principal Engineer to architect, design, and operate secure, scalable enterprise platforms across on‑premises and AWS. You will lead development, deployment, and ongoing maintenance with a focus on reliability and cost-effectiveness, collaborating across geographies and teams.

The ideal candidate brings strong .NET/C#, SQL, AWS experience, and a track record in building distributed systems, DevOps practices, and cloud security.

Qualifications

• Bachelor's degree or equivalent experience.
• .NET/C# and MS SQL experience.
• Distributed systems in on-prem and AWS.
• AWS cloud services and cloud architecture best practices.
• Relational and NoSQL databases (DynamoDB).
• Message brokers and event-driven architectures (Kafka, RabbitMQ).
• CI/CD tools like Jenkins, GitLab CI, Ansible, Terraform.
• Observability platforms such as Datadog or Prometheus.
• Disaster recovery planning and drills.
• Cloud security best practices including IAM, encryption, audits.

Responsibilities

• Design and build highly available enterprise applications and optimise mission-critical systems.
• Collaborate with stakeholders across geographies and cross-functional teams to gather requirements.
• Define and enforce technical standards, design patterns, and API security best practices.
• Design and build on-prem and AWS infrastructure ensuring high availability.
• Troubleshoot complex distributed systems and support critical issues.
• Lead cloud security posture management in line with enterprise standards.
• Drive observability using tools like Datadog to monitor performance and reliability.
• Mentor a diverse, high-performing team of engineers toward automation and improvement.

Skills

.NET/C#

MS SQL

Distributed systems

AWS

DevOps practices

API design

Security best practices

Observability

Mentoring

Education

Bachelor's degree in Computer Science, Engineering, or related field

Tools

Datadog

Prometheus

Jenkins

GitLab CI

Ansible

Terraform

Kafka

RabbitMQ

Job description

ABOUT US:

LSEG (London Stock Exchange Group) is more than a diversified global financial markets infrastructure and data business. We are dedicated, open-access partners with a dedication to excellence in delivering the services our customers expect from us. With extensive experience, deep knowledge and worldwide presence across financial markets, we enable businesses and economies around the world to fund innovation, manage risk and create jobs. It's how we've contributed to supporting the financial stability and growth of communities and economies globally for more than 300 years. Through a comprehensive suite of trusted financial market infrastructure services - and our open-access model - we provide the flexibility, stability and trust that enable our customers to pursue their ambitions with confidence and clarity.

OUR PEOPLE:

People are at the heart of what we do and drive the success of our business. Our culture of connecting, creating opportunity and delivering excellence shape how we think, how we do things and how we help our people fulfil their potential. We embrace diversity and actively seek to attract individuals with unique backgrounds and perspectives. We break down barriers and encourage teamwork, enabling innovation and rapid development of solutions that make a difference. Our workplace generates an enriching and rewarding experience for our people and customers alike. Our vision is to build an inclusive culture in which everyone feels encouraged to fulfil their potential.

We know that real personal growth cannot be achieved by simply climbing a career ladder - which is why we encourage and enable a wealth of avenues and interesting opportunities for everyone to broaden and deepen their skills and expertise. As a global organisation spanning 70 countries and one rooted in a culture of growth, opportunity, diversity and innovation, LSEG is a place where everyone can grow, develop and fulfil your potential with meaningful careers.

ROLE SUMMARY:

We are looking for a Principal Engineer with strong architecture and system design skills to build and maintain administrative platforms across on‑premises and cloud environments. You will help us design, build, and operate secure, reliable, scalable, and cost‑effective systems.

The ideal candidate will have a strong background in software engineering, solution architecture, enterprise application development, and DevOps practices and tooling, with particular expertise in .NET/C#, AWS, and Microsoft SQL Server. You will play a key role within our technology team, contributing to the architecture, design, development, deployment, operation, and ongoing maintenance of our systems.

WHAT YOU'LL BE DOING:

• Design and build highly available enterprise applications, applying strong debugging skills to optimise mission‑critical systems.
• Collaborate with stakeholders across multiple geographies and cross‑functional teams to understand project objectives, gather requirements, and deliver systems and software within agreed upon timelines.
• Define and enforce technical standards, design patterns, and best practices for API design, development, and security.
• Design and build on‑prem and AWS infrastructure ensuring high availability.
• Troubleshoot complex distributed systems and support the resolution of critical technical issues.
• Lead cloud security posture management by designing systems in accordance with enterprise security standards.
• Drive observability efforts using tools like Datadog to monitor infrastructure and application performance.
• Mentor a high‑performing, geographically diverse team of software engineers, fostering a culture of collaboration, automation, and continuous improvement.

WHAT YOU'LL BRING:

• Bachelor's degree in Computer Science, Engineering, or related field, or equivalent experience.
• Strong hands‑on experience with .NET/C# and MS SQL.
• Extensive experience building highly‑available distributed systems in on‑prem and AWS.
• Strong hands‑on experience with AWS cloud services (EKS, EC2, S3, RDS, Lambda, API Gateway, ECS, VPC, IAM, CloudWatch, etc.) and cloud architecture best practices.
• Strong hands‑on experience with relational databases and NoSQL databases (e.g. DynamoDB).
• Strong hands‑on experience with message brokers and event‑driven architectures (e.g., Kafka, RabbitMQ).
• Hands‑on experience with CI/CD tools (e. g. Jenkins, GitLab CI, Ansible, Terraform).
• Experience with observability platforms such as Datadog, Prometheus, or equivalent.
• Track record of designing and executing disaster recovery plans and drills.
• Solid knowledge of Cloud security best practices including IAM policies, encryption, vulnerability scanning, and compliance audits.

Nice to have:

AWS Certifications such as AWS Ce