Senior C# Developer with Fintech experience

MARGO; Warszawa; On-site; PLN 234,192 - 316,848; Part time

Job summary

MARGO is looking for a Senior C# Developer in Warsaw, Poland, to join an international team focused on core systems in XVA and financial resource management.

The ideal candidate will have strong skills in C# and .NET, alongside experience in financial products. This role offers flexibility and a collaborative agile environment.

Qualifications

• Experience with XVA, liquidity, and financial resource management.
• Expertise in at least 2 financial areas such as PnL explain and liquidity risk.

Responsibilities

• Develop core systems in a modern event-driven architecture.
• Collaborate in an agile environment emphasizing clean code.

Skills

OOP principles

.NET C# ecosystem

Service-oriented architectures

MS SQL

DevOps tools

LLM capabilities

Tools

GIT (Bitbucket)

TeamCity

Jenkins

Ansible

Job description

On behalf of our client – a global financial institution – we are looking for an experienced specialist for the position of Senior C# Developer.

About the Project & Team

You will join a distributed, international team responsible for the development of core systems in the areas of XVA, Liquidity, and Financial Resource Management. The project is currently at an exciting turning point – migrating to a modern, highly advanced event-driven architecture on the back-end side. The developed UI tools support the daily operations of hundreds of users in a dynamic market environment. We work in a collaborative, agile environment with a strong emphasis on clean code and software craftsmanship.

170 zł – 230 zł an hour

Tech Stack

• Language & Frameworks: C# .NET, Windows Services, ASP.NET Web API, SignalR
• Communication: Asynchronous message-driven communication (Rebus)
• Databases & ORM: MS SQL, ORM (Dapper)
• Tools & DevOps: GIT (Bitbucket), TeamCity, Jenkins, Ansible

Required Technical Competencies

• Deep understanding & experience: OOP, patterns, principles.
• Deep understanding & experience: .NET C# and its ecosystem.
• Deep understanding & experience: service-oriented architectures.
• Deep understanding & experience: MS SQL.
• Demonstrable experience: DevOps tools.
• Understanding of LLM capabilities in software development; practical experience with agentic AI engineering in an enterprise environment.

Functional / Financial Knowledge

Candidates are required to have expertise in at least 2 areas from the following list:

• Financial products (Listed / OTC)
• PnL Explain, risks (Delta, Gamma, Theta, Vega...)
• XVA (CVA, FVA, ColVA...)
• Liquidity Risk (RNFB, NSFR...)
• Cash Forecasting
• Balance Sheet Metrics (Leverage Exposure...)
• Pre-trade calculation and booking workflow

Nice to Have

• Web development experience: HTML, JavaScript / TypeScript, React, Redux.

Conduct & Attitude Expectations

• High autonomy combined with excellent teamwork skills.
• Excellent communication, analytical, and organisational skills.
• Attention to detail (especially under time pressure).
• Proactive, flexible approach to daily engineering challenges.
• Motivation to work directly with front-office IT.
• Integrity and discipline.
• Role model supporting a culture of good conduct.
• Proactivity, transparency, and accountability in managing conduct risks.
• Considering the impact of decisions on colleagues, partners, and clients; escalation in case of doubts.