Application Engineer

Janus Henderson Group; Greater London; Hybrid; GBP 60,000 - 90,000; Full time

Benefits offered by this job

Hybrid working

Generous holiday policies

Volunteer time

Professional development support

Job summary

Janus Henderson Group is seeking a software engineer to develop and maintain services in C#/.NET within a hybrid environment. You will work on features end-to-end, including backend services, frontend components, and cloud infrastructure, while collaborating with architects and IT product owners to align with architectural vision.

The role emphasizes writing tests, contributing to CI/CD, and mentoring junior staff as you grow into ownership of components.

Qualifications

• 2-6 years of commercial software engineering, with strong C# and .NET (.NET 6/8 or equivalent).
• Solid ASP.NET Core: DI, configuration, middleware, authentication, async/await.
• Competent SQL – write and tune queries and reason about data models.
• Genuine testing discipline: unit testing and mocking as a normal part of writing code.
• Practical Git and CI/CD experience; branching, PRs and automated pipelines.
• Working knowledge of Azure cloud platform.

Responsibilities

• Deliver features and fixes end-to-end: C# service code, Angular UI, Terraform, pipeline config and deployment to production.
• Build and maintain integrations with vendor trading platforms via REST APIs, event subscriptions and batch feeds.
• Write unit and integration tests meeting coverage gates and treat findings as defects.
• Author and maintain Snowflake and SQL Server migration scripts with versioned conventions.
• Investigate production issues using Application Insights and Dynatrace and participate in the support rota.
• Review colleagues' pull requests and maintain traceable change records in Jira and ServiceNow.
• Contribute to modernising legacy components as functionality migrates to the current platform.

Skills

C#/.NET

ASP.NET Core

SQL

Unit testing

Git/CI-CD

Azure

Communication

Education

Bachelor's degree in Computer Science

Tools

Terraform

Snowflake

Job description

This position will be posted for a minimum of five calendar days internally. All internal applicants are required to inform your current supervisor/manager prior to applying. Internal applicants are required to be in "good standing" in your current role, which is defined as a performance rating of "met all objectives" or higher. You cannot be on a current performance improvement plan or written warning for any reason and must have been in your current role for a minimum of 6 months, unless otherwise approved for an early transfer by your current leader and the People Department.

Your opportunity Work closely with the JHI business users, team and IT product owners to develop business solutions and add business value through software solutions. Collaborate with Architects and Tech Leads, ensuring that all solutions fit well within the strategic architectural vision. Deliver and support production services across the Trading estate. Writing the code, the tests, the infrastructure and the pipeline changes that take a piece of work from a Jira ticket to a running service used by traders and portfolio managers. You will work within an established architecture and quality bar rather than defining it, and will grow into ownership of individual components. Work in an agile team, contributing to team velocity, ideation and success! Assist in mentoring junior staff where appropriate, promoting a positive company culture. Opportunity to grow your skills base, being included in forward thinking R&D and innovation toward JHIs goals. Work within a progressive company committed to DEI goals. Carry out other appropriate duties as assigned.

What to expect when you join our firm

• Hybrid working and reasonable accommodations
• Generous Holiday policies
• Paid volunteer time to step away from your desk and into the community
• Support to grow through professional development courses, tuition/qualification reimbursement and more
• All-inclusive approach to Diversity, Equity and Inclusion
• Maternal/paternal leave benefits and family services
• Complimentary subscription to Headspace - the mindfulness app
• Corporate membership to Wellhub and other health and well-being benefits
• All employee events
• Lunch allowance for use within subsidized onsite canteen (UK Only)

Key responsibilities

• Deliver features and fixes end to end: C# service code, Angular UI where relevant, Terraform, pipeline configuration and deployment through to production.
• Build and maintain integrations with vendor trading platforms (Charles River, Aladdin, Bloomberg and others) via REST APIs, event subscriptions and batch file feeds. Work within the ports-and-adapters structure – keeping domain logic free of vendor and infrastructure concerns and confining external dependencies to adapters.
• Write unit and integration tests sufficient to meet the enforced coverage gates and treat analyzer findings as defects rather than noise.
• Author and maintain Snowflake and SQL Server migration scripts following the established versioned/repeatable conventions.
• Support the services you build investigate production issues using Application Insights and Dynatrace, participate in the support rota, and carry out root‑cause fixes.
• Review colleagues' pull requests constructively and respond to review of your own.
• Keep change traceable – accurate Jira references and correct ServiceNow change records for production releases.
• Contribute to incremental modernisation of legacy components as functionality is migrated onto the current platform.

Must Have Skills

• 2-6 years of commercial software engineering, with strong C# and .NET (.NET 6/8 or equivalent recent experience).
• Solid ASP.NET Core: dependency injection, configuration, middleware, authentication, and correct use of async/await.
• Competent SQL – able to write and tune queries, and to reason about data models.
• Genuine testing discipline: unit testing and mocking as a normal part of writing code, not an afterthought.
• Practical Git and CI/CD experience; comfortable with branching, pull requests and automated build and release pipelines.
• Working knowledge of a major public cloud, ideally Azure.
• Able to read unfamiliar code and work safely in a large existing codebase.
• Clear written and verbal communication with non-technical colleagues.

Nice to Have Skills

• Azure Functions (isolated worker), Service Bus or Event Grid, Key Vault.
• Angular and TypeScript, particularly with ag-Grid or PrimeNG.
• Terraform or another infrastructure-as-code tool.
• Snowflake, or cloud data warehousing generally.
• Financial services background, especially asset management, trading or capital markets.
• Exposure to any of Charles River, Aladdin or Bloomberg.

Supervisory responsibilities

Supervisory responsibilities No Potential for growth Mentoring Leadership development programs Regular training Career development services Continuing education courses Compliance requirements At a minimum the role will require you to: Place the interest of Janus Henderson's Clients first, act in accordance with TCF (Treatin