senior c#

MARGO; Warsaw (IN); On-site; USD 120,000 - 170,000; Full time

Benefits offered by this job

Remote work expense allowance

Private medical care

Lunch card

Pension plan

Multisport card

Life insurance

Parking in office

Job summary

Doist is seeking a Senior C# Developer to join Global Markets IT, contributing to XVA, liquidity, and cash‑forecasting solutions. You will help migrate services to an event‑driven architecture and implement asynchronous messaging with Rebus, while upholding SOLID principles and clean architecture.

You will work in an agile environment across distributed teams, participate in DevOps workflows, and mentor engineers to deliver robust software with detailed documentation.

Qualifications

• 5+ years of professional experience with C#/.NET (Windows Services, ASP.NET Web API, SignalR)
• Strong command of Object‑Oriented Programming, design patterns, and SOLID principles
• Proven experience with service‑oriented architectures and asynchronous messaging (Rebus)
• Advanced knowledge of MS SQL and hands‑on with DevOps tools: Git/Bitbucket, TeamCity/Jenkins, Ansible
• Familiarity with ORM libraries (e.g., Dapper) and version‑controlled build pipelines
• Understanding of the capabilities of LLMs in the software development process with practical experience of agentic AI engineering in an enterprise environment
• Excellent communication skills in English (C1)

Responsibilities

• Design, develop, and evolve high‑performance C#/.NET services that power XVA, liquidity and cash‑forecasting workflows.
• Contribute to the migration to a modern, event‑driven architecture.
• Implement asynchronous, message driven communication using Rebus and ensure data integrity.
• Participate in full‑cycle DevOps processes: source control (Bitbucket/GIT), CI/CD pipelines (TeamCity, Jenkins), and configuration management (Ansible).
• Apply knowledge of Large Language Models (LLMs) and agentic AI to improve coding efficiency, code review, and automated testing within an enterprise setting.
• Provide technical mentorship, conduct code reviews, and champion best‑practice patterns (OO design, SOLID, clean architecture).
• Deliver high‑quality software under tight deadlines while maintaining attention to detail and robust documentation.

Skills

C#/.NET

OO design / SOLID

Async messaging (Rebus)

DevOps / CI-CD

English communication

Mentorship

Tools

Rebus

Git/Bitbucket

TeamCity/Jenkins

Ansible

Dapper ORM

Job description

Description & Requirements

We are seeking a Senior C# Developer to join the Non‑Linear IT team within Global Markets IT. The team builds and maintains the core applications that support XVA, liquidity, and financial‑resource management. You will work in an agile, collaborative environment in team distributed between London, Paris and Kraków, delivering clean, maintainable code while helping migrate our back‑end services to a modern event‑driven architecture.

Senior C# Developer Responsibilities

• Design, develop, and evolve high‑performance C#/.NET services that power XVA, liquidity and cash‑forecasting workflows.
• Contribute to the migration to a modern, event‑driven architecture.
• Implement asynchronous, message driven communication using Rebus and ensure data integrity.
• Participate in full‑cycle DevOps processes: source control (Bitbucket/GIT), CI/CD pipelines (TeamCity, Jenkins), and configuration management (Ansible).
• Apply knowledge of Large Language Models (LLMs) and agentic AI to improve coding efficiency, code review, and automated testing within an enterprise setting.
• Provide technical mentorship, conduct code reviews, and champion best‑practice patterns (OO design, SOLID, clean architecture).
• Deliver high‑quality software under tight deadlines while maintaining attention to detail and robust documentation.

Requirements

• 5+ years of professional experience with C#/.NET (Windows Services, ASP.NET Web API, SignalR).
• Strong command of Object‑Oriented Programming, design patterns, and SOLID principles.
• Proven experience with service‑oriented architectures and asynchronous messaging (Rebus).
• Advanced knowledge of MS SQL and hands‑on with DevOps tools: Git/Bitbucket, TeamCity/Jenkins, Ansible.
• Familiarity with ORM libraries (e.g., Dapper) and version‑controlled build pipelines.
• Understanding of the capabilities of LLM's in the software development process with practical experience of agentic AI engineering in an enterprise environment.
• Excellent communication skills in English (C1).

Nice‑to‑Have

• Front‑end development experience with HTML, JavaScript/TypeScript, React, Redux.
• Financial domain knowledge: 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.

We offer

• Equivalent for remote work expenses (120 PLN per month).
• Stable employment in the international company.
• Fully paid private medical care for employee.
• Pre‑paid lunch card.
• Employee Pension Plan.
• Co‑financed Multisport Card.
• Life insurance.
• Car parking availability in the office building.
• Trainings and development opportunities.