Senior Software Engineer – Real-Time Data Platform

Morningstar; Greater London; On-site; GBP 68,000 - 95,000; Full time

Job summary

Morningstar in Greater London seeks a Senior Software Engineer to build and operate a real-time data platform that powers the business. You will handle a distributed, event-driven system processing billions of market data messages daily, ensuring reliability at scale.

You’ll design and implement scalable data processing with Flink and Kafka, using Java or .NET, while emphasizing observability, cost efficiency, and production readiness. The role features a hybrid work model in London.

Qualifications

• Experience in building distributed, low-latency systems.
• Proficiency with event-driven architectures and streaming data.
• Strong coding skills in Java or .NET and real-time data processing.
• Ability to design for observability, monitoring, and reliability.

Responsibilities

• Design and build scalable, real-time data processing systems using Flink, Kafka.
• Develop high-quality code for data processing and APIs in Java/.NET.
• Lead system design with end-to-end ownership from development to production.
• Build production-grade systems with strong observability and operational excellence.
• Collaborate with AWS, Terraform, and CI/CD tooling to ship reliably.

Skills

Distributed systems

Event-driven

Apache Flink

Kafka

.NET or Java

Observability

Tools

Apache Flink

Kafka

Terraform

Harness

AWS

Job description

Senior Software Engineer – Real-Time Data Platform Morningstar Greater London, Greater London, United Kingdom

This job is with Morningstar, an inclusive employer and a member of myGwork – the largest global platform for the LGBTQ+ business community. Please do not contact the recruiter directly.

We're looking for a Senior Software Engineer to join our team building and operating the core data platform that powers our business. This platform sits at the heart of everything we do, delivering high-quality, real-time market data to systems and teams across the organisation.

If you enjoy working on high-throughput, low-latency systems at massive scale, and want to take ownership of meaningful, business-critical problems, this role is for you.

About the Role

You’ll be working on a distributed, event-driven platform responsible for processing billions of market data messages per day. This is a high-performance environment where reliability, scalability, and correctness are essential.

Our platform acts as the backbone of the business, ensuring that accurate and timely market data flows seamlessly to downstream systems that depend on it for analytics.

You’ll collaborate closely with engineers, product teams, and stakeholders to design, build, and operate resilient systems that handle extreme data volumes with precision‑while also maintaining a strong focus on cost efficiency, scalability, and operational excellence.

Key Responsibilities

• Design and build scalable, real-time data processing systems using technologies like Apache Flink, Kafka.
• Develop high-quality, maintainable code for Apache Flink (Java) data processing and .NET APIs.
• Lead and contribute to collaborative system design, while taking end-to-end ownership of implementation through to production support.
• Build production‑grade systems with a strong focus on observability, monitoring, and operational excellence, enabling rapid detection and resolution of issues.
• Work with AWS services to build cloud‑native, highly available systems.
• Define and manage infrastructure using Terraform.
• Implement CI/CD pipelines and deployment workflows using tools like Harness.
• Optimise systems for performance, latency, throughput, and cost.

What We’re Looking For

• Excellent collaboration and communication skills.
• Strong experience in distributed systems and event‑driven architectures.
• Hands‑on experience with: Apache Flink (or similar stream processing frameworks) Kafka or other messaging systems.
• Strong Proficiency in .NET or Java.
• Experience building systems that are highly observable and operationally mature, with strong monitoring, logging, and alerting practices.
• Strong understanding of performance tuning, scalability, and fault tolerance.
• Good understanding of cost implications when designing systems, including the ability to project costs as we scale.

Why Join Us

• Work on systems that are mission‑critical to the entire business
• Operate and evolve a platform handling billions of messages per day
• Solve complex engineering challenges at massive scale
• Be part of a team that values ownership, collaboration, and delivery
• Opportunity to shape a high‑performance, cost‑efficient, and highly observable data platform

Base Salary Compensation Range

GBP 68,200.00-95,333.33

12.5% Annual

We expect the compensation and target bonus for this role to fall within the stated range. The specific compensation offered will depend on the candidate’s qualifications, experience, and other job-related factors.

Morningstar’s hybrid work environment gives you the opportunity to collaborate in‑person each week as we’ve found that we’re at our best when we’re purposely together on a regular basis. In most of our locations, our hybrid work model is four days in-office each week. A range of other benefits are also available to enhance flexibility as needs change. No matter where you are, you’ll have tools and resources to engage meaningfully with your global colleagues.

301_MstarEurLtd Morningstar Europe Ltd (UK) Legal Entity

Full-time