Senior Software Engineer

Collins McNicholas Group; Cork; Hybrid; EUR 90,000 - 130,000; Full time

Job summary

Collins McNicholas Group is seeking a Senior Software Engineer to join our Financial Technology client in Cork on a hybrid model (3 days in the office, 2 from home). You will contribute to building a scalable data platform and ship production-grade backend systems.

The role emphasizes event-driven ingestion, versioned APIs, accurate data, and cost-aware scalability. You will mentor others, work with Python and C#/.NET, SQL, Snowflake, dbt, Terraform and Azure, and help ensure reliable, auditable

Qualifications

• 8–10 years of backend software experience in production.
• Backend exp with Python, C#/.NET; Python and C# are main techs.
• Strong distributed systems knowledge (idempotency, ordering, retries).
• Strong testing practices (unit/integration, CI).
• Experience evolving APIs and data schemas with versioning.
• Strong SQL skills and cloud data warehouse cost awareness.

Responsibilities

• Build reliable data ingestion services with exactly-once processing.
• Develop secure, versioned APIs, SDKs, and data feeds.
• Create point-in-time history and precise decimal calculations for reproducibility.
• Scale services and storage while controlling costs through testing and load analysis.
• Build tooling for self-service onboarding in a multi-tenant platform.
• Ensure AI/ML-ready data with tenant separation and reproducibility.
• Define operability: SLOs, monitoring, alerting, and CI controls; own incidents.

Skills

Distributed systems

Backend development

Python

C#/.NET

SQL

Testing

APIs & versioning

Mentoring

Tools

Snowflake

dbt

Terraform

Azure

GitHub Actions

Job description

Senior Software Engineer – Data Plaftorm

Location: Cork, Ireland (Hybrid – 3 days in office, 2 from home)
Industry: Financial Technology

An exciting opportunity has opened up for an experienced Senior Software Engineer to join a growing FinTech company and contribute to building their data platform. Some products already run on it, others are in the process of being moved over, and new products will be built on it from the start. You will need to have shipped and run production backend systems and you need to care whether the data is correct.

Key Responsibilities

• Event-driven ingestion: Build reliable data ingestion services that handle retries, redelivery, reordering and late changes while ensuring exactly-once results.
• Versioned APIs & contracts: Develop secure, tested and versioned APIs, SDKs and data feeds that can evolve without disrupting downstream teams.
• Accurate, reproducible data: Build point-in-time history and precise decimal calculations into the platform so results can always be reproduced.
• Scalable & cost-efficient: Scale services and storage significantly while maintaining performance and controlling costs through measurement and load testing.
• Self-service onboarding: Build tooling and services that enable new products and customers to onboard quickly within a multi-tenant platform.
• AI/ML-ready data: Ensure customer data is accessible for AI and ML while maintaining strong contracts, tenant separation and reproducibility.
• Built-in operability: Implement SLOs, monitoring, alerting and CI controls, while taking ownership of incidents and preventing recurrence.

Requirements

• Ideally 8-10 years experience building software, including backend services you designed, deployed and ran in production.
• Backend development experience with Python, C#/.NET, Java or similar. Python and C# are the main technologies used.
• Strong distributed systems knowledge, including idempotency, concurrency, ordering, retries and exactly-once processing.
• Strong testing practices, including unit/integration testing and CI.
• Experience evolving APIs and data schemas, including versioning and backward compatibility.
• Strong SQL skills and an understanding of cloud data warehouse performance and costs.
• Collaborative approach, with experience mentoring through code reviews, pairing and clear documentation.
• The stack is Python and C#/.NET, Snowflake, dbt, Terraform, Azure (Functions, Container Apps, Service Bus), GitHub Actions.
• Ability to work within a small team with high autonomy.