Senior Backend Engineer (FIX & Identity)
Description
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.
Core skills you’ll bring
5+ years building backend systems, ideally in C#/.NET. Strong Java engineers are welcome too, and we will give you time to move to .NET
Real experience with the FIX protocol on electronic trading platforms in fintech or capital markets
Hands-on work with login and access control (OAuth2, OpenID Connect, IdentityServer or similar)
Designing and building APIs that other teams rely on
Solid experience with message-based, event-driven systems
Experience with financial calculations, such as pricing, where small rounding errors matter
Comfort with MongoDB or another NoSQL database
Some experience with monitoring tools such as Datadog, Sentry or Elasticsearch
Clear communication and a habit of working well with product, frontend and DevOps colleagues
Nice-to-have
Knowledge of fixed income or securities pricing
Experience with QuantLib or other quantitative finance libraries
Live data streaming with SignalR or WebSockets
Exposure to Pulsar, Databricks or Lakehouse setups
Some React and Redux for light frontend work
The impact you'll create
Build the services behind a trading platform, where speed and accuracy matter every day
Connect the platform to banks, brokers and venues through FIX
Make sure the right people have the right access across all our services
Shape how pricing and financial calculations are done, with exact results
Help keep the system reliable and easy to monitor as it grows
Share your experience with other engineers and help set good engineering standards
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.