Senior .NET Developer (FIX Protocol)

.Net

Poland

Fully Remote

Senior .NET Developer (FIX Protocol)

Apply now

Avenga is an international engineering firm helping businesses operate with AI at the core. With 6,000+ experts worldwide, we combine engineering expertise with AI-native thinking to turn ambitious ideas into real-world impact across industries, technologies, and markets.

At the core of the role

We are looking for strong backend engineer with experience in the FinTech domain, working on a microservices and event-driven architecture based on .NET, MongoDB, Redis, RabbitMQ (MassTransit), Pulsar, and Elasticsearch. Experienced in designing scalable distributed systems and collaborating within a 7-person engineering team. Additionally exposed to React development.

Core skills you’ll bring

• 5+ years of backend development experience
• Strong C#/.NET (Java may be considered)
• Experience building and designing APIs
• Distributed messaging systems and event-driven architectures
• FIX Protocol experience in a capital markets / electronic trading environment
• Experience with financial calculations, pricing engines, or quantitative models
• Hands-on experience with QuantLib (or similar quantitative finance libraries)
• OAuth2, OpenID Connect, IdentityServer or similar authentication frameworks
• MongoDB or other NoSQL databases
• Experience in capital markets, fintech, trading platforms, fixed income, securities pricing

Nice-to-have

• Datadog, Sentry, Elasticsearch
• SignalR / WebSockets
• Pulsar, Databricks, Lakehouse
• React + Redux (nice to have)
• Experience mentoring engineers / technical leadership

The impact you'll create

• Design and develop high-quality backend services using C#/.NET
• Build and maintain ASP .NET service-side applications with a focus on scalability and long-term reliability.
• Work with distributed messaging frameworks and event-driven architectures to support high-throughput trading systems.
• Develop and optimize data solutions using NoSQL databases such as MongoDB.
• Design and implement financial calculation engines, pricing models, and quantitative algorithms with a strong emphasis on accuracy and performance.
• Implement and maintain FIX protocol integrations to support electronic trading workflows.
• Design and enforce identity, authentication, and authorization solutions across backend services.
• Integrate and work with observability platforms such as Datadog or Elasticsearch to support system monitoring and diagnostics.
• Ensure numerical precision in financial computations, including proper handling of rounding, accruals, and market conventions.
• Collaborate with product, UI/UX, frontend, and DevOps teams to align on development and deployment strategy.
• Build reusable, testable backend infrastructure and uphold consistent coding standards across teams.
• Implement telemetry and monitoring best practices using Sentry or equivalent tools.
• Evaluate and adopt new technologies, frameworks, and design patterns to continuously improve engineering outcomes.
• Mentor engineers on backend development best practices and foster a culture of engineering excellence.
• Contribute to frontend solutions using React and Redux/Rematch where needed. (nice to have)

People are at the core of Avenga. We provide equal opportunities regardless of race, ethnicity, gender identity, sexual orientation, disability, age, religion, or any other characteristic. We are committed to a respectful environment where everyone can be themselves, share their ideas, and feel that they belong.

Department

.Net

Location

Poland

Remote status

Fully Remote

Technology

.NET

Seniority

Senior-level

Take the first step toward your career at Avenga

APPLICATION

Send your CV to tell us about your core skills and what you're looking for next.

TALENT CALL

Meet our Talent team to talk about your goals and experience while exploring our culture and the way we work.

TECHNICAL INTERVIEW

We'll explore your experience, strengths, and approach to work to see what we can build together.

CUSTOMER INTERVIEW

For some roles, you'll meet our customers to understand the outcomes your expertise can help create.

WELCOME TO AVENGA

An offer is just the beginning. We welcome you to put your expertise into action and shape what's next together.

Apply now

.Net

Poland

Fully Remote

Senior .NET Developer (FIX Protocol)

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