.NET Principal Tech Lead — AI-Driven Modernisation

Stelfox Tech Recruitment; Ireland; Hybrid; EUR 130,000 - 170,000; Full time

Job summary

Stelfox is partnering with a Fintech provider in Cork City to modernise their product and platform, embracing AI-first development to extend Agentic AI services for financial institutions. The Principal Technical Lead will drive the modernisation, decompose legacy systems, and own the hardest problems—writing production code daily and guiding engineering practices.

The role focuses on leading modernisation, bridging legacy and modern architectures, and leveraging AI to accelerate product

Qualifications

• Expert-level experience with .NET/C# and modern patterns (async/await, DI, clean architecture).
• Cloud-native development on Azure; AWS/GCP transferable.
• Database design, optimization, and migration for high-volume systems.

Responsibilities

• Lead the modernisation—decompose legacy monoliths into scalable services.
• Write production code daily and review PRs; no excessive meetings.
• Raise the technical bar with testing, patterns, and automation; ship incrementally.

Skills

NET/C#

Azure

API design

Testing strategies

Refactoring

Microservices

CI/CD

Legacy modernization

Tools

Azure DevOps

Job description

Stelfox is partnering with a Fintech provider in Cork City to modernise their product and platform, embracing AI-first development to extend Agentic AI services for financial institutions. The Principal Technical Lead will drive the modernisation, decompose legacy systems, and own the hardest problems—writing production code daily and guiding engineering practices.

The role focuses on leading modernisation, bridging legacy and modern architectures, and leveraging AI to accelerate product