Principal Engineer (.NET & Azure - Fully Remote) in London

Payments Recruitment; City Of London; Remote; GBP 100,000 - 120,000; Full time

Job summary

A leading payments solutions company is seeking a Principal Engineer with extensive .NET and Azure expertise. This fully remote role focuses on designing scalable systems and modernizing legacy applications while providing mentorship to junior developers. Candidates should possess deep knowledge of payments processing and strong problem-solving abilities to enhance the platform's performance and reliability. The company promotes a culture of continuous learning and offers flexibility to support work-life balance.

Benefits

Flexible working environment

Opportunity for professional growth

Supportive team culture

Qualifications

• 8+ years of professional .NET development experience.
• Strong knowledge of Azure services.
• Experience with high-transactional systems.

Responsibilities

• Design and build scalable, high-performance .NET services.
• Lead improvements in the software lifecycle.
• Ensure reliability through failover and redundancy.

Skills

Cloud architecture design

High-performance .NET development

Mentorship

Payments processing knowledge

Experience with data lakes

Tools

Azure Data Lake

Azure Synapse

Databricks

Job description

Principal Engineer (.NET & Azure)

£100-120K + bonus + benefits

Fully remote – EU & UK

Our client is a scale up payments platform with a fantastic founding team. They are keen to hire an outstanding Principal Engineer to join the technical team. This role is fully remote & can be performed from anywhere within the UK or EU.

We need a highly motivated individual who has genuine depth of knowledge in payments technology, high volume enterprise scale systems, software development & engineering. We are currently maintaining our legacy system, and you will join to review where we are now – what we’ve got – and where we want to get to. We want our platform to be a class leading, robust & resilient solution for our merchants to rely on.

Not only are you an expert software developer, but you will also be able to influence and guid a development team. You can design our next generation solution and implement it, with a clear career roadmap into a Head of Engineering role. With a new platform architecture project comes a huge amount of autonomy, giving you the opportunity to work closely with the CTO, development team and various payment portals, widgets and solutions, and get the plans & processes in place to build a bigger team as we move forward.

The role

Senior .NET Developer / Azure Solutions Engineer

Enterprise-scale systems | Azure | Data Engineering

We’re looking for an experienced .NET developer with strong architectural skills to help us take our platform to the next level. If you love solving complex problems, thrive in high-throughput environments, and enjoy shaping the way software is built and run, this role is for you.

What you’ll do

• Design and build scalable, high-performance .NET services and components.
• Play a key role in re-architecting legacy systems into modern, reliable, cloud-ready solutions.
• Lead improvements across the software lifecycle — from testing and deployments to logging, monitoring, and observability.
• Ensure reliability through failover, redundancy, and recovery strategies.
• Shape our data infrastructure, including pipelines into data lakes and warehouses (Azure Data Lake, Synapse, Databricks, etc.).
• Define and promote engineering best practices across the team, mentoring developers along the way.
• Architect and manage Azure-hosted infrastructure and services, ensuring scalability and performance.
• Champion a DevOps culture with automation, resilience, and operational readiness at its core.

What we’re looking for

• 8+ years of professional .NET development experience.
• Proven experience with high-transactional systems and large-scale databases.
• Strong knowledge of Azure services.
• Deep technical knowledge of payments processing, card processing & settlements.
• Hands-on experience with data lakes and data warehouses.
• Track record designing and maintaining distributed, fault-tolerant systems.
• Solid understanding of environment separation (dev/test/staging/prod) and deployment workflows.
• Comfortable with automated testing, version control, and release processes.
• A natural mentor with a genuine interest in raising the bar for the whole team.

Why join us

• Work on mission-critical systems that demand scale, resilience, and performance.
• Real influence on the technical direction of the platform.
• A culture that values continuous learning, innovation, and strong engineering principles.
• Opportunity to mentor and shape the next generation of developers.
• Flexible, supportive working environment, great reward, autonomy & a brilliant team of supportive people around you.