Senior .NET Developer (FIX Protocol)

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 roleWe 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. The profile aligns well with modern backend and distributed systems requirements; however, further verification is needed regarding FIX Protocol, electronic trading systems, and quantitative finance/pricing engine experience.Core skills you’ll bring5+ years of backend development experienceStrong C#/.NET (Java may be considered)Experience building and designing APIsDistributed messaging systems and event-driven architecturesFIX Protocol experience in a capital markets / electronic trading environmentExperience with financial calculations, pricing engines, or quantitative modelsHands-on experience with QuantLib (or similar quantitative finance libraries)OAuth2, OpenID Connect, IdentityServer or similar authentication frameworksMongoDB or other NoSQL databasesExperience in capital markets, fintech, trading platforms, fixed income, securities pricingNice-to-haveDatadog, Sentry, ElasticsearchSignalR / WebSocketsPulsar, Databricks, LakehouseReact + Redux (nice to have)Experience mentoring engineers / technical leadershipThe 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-termreliability.• Work with distributed messaging frameworks and event-driven architectures to support high-throughputtrading systems.• Develop and optimize data solutions using NoSQL databases such as MongoDB.• Design and implement financial calculation engines, pricing models, and quantitative algorithms with astrong 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 systemmonitoring 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 deploymentstrategy.• 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 improveengineering outcomes.• Mentor engineers on backend development best practices and foster a culture of engineeringexcellence.• 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.