Senior .NET Developer (FIX Protocol)

Location: Poland; fully remote

Company

hirify.global is an international engineering firm helping businesses operate with AI-native engineering expertise across industries and technologies.

What you will do

• Design and develop scalable, reliable backend services and ASP.NET server-side applications using C#/.NET.
• Build distributed messaging and event-driven architectures for high-throughput trading systems.
• Develop NoSQL data solutions with MongoDB and implement FIX Protocol integrations for electronic trading workflows.
• Design financial calculation engines, pricing models, and quantitative algorithms with accurate handling of rounding, accruals, and market conventions.
• Implement authentication, authorization, telemetry, monitoring, and observability across backend services.
• Collaborate with product, UI/UX, frontend, and DevOps teams; mentor engineers and contribute to React solutions where needed.

Requirements

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

Nice to have

• Datadog, Sentry, or Elasticsearch experience.
• SignalR or WebSockets experience.
• Pulsar, Databricks, or Lakehouse experience.
• React with Redux or Rematch experience.
• Experience mentoring engineers or providing technical leadership.

Culture & Benefits

• Fully remote work from Poland.
• Collaboration within a 7-person engineering team and with product, frontend, UI/UX, and DevOps functions.
• Respectful, inclusive environment with equal opportunities regardless of personal characteristics.
• Commitment to reusable, testable infrastructure, consistent coding standards, and engineering excellence.

Hiring process

• Submit a CV describing core skills and career goals.
• Complete a talent call, technical interview, and, for some roles, a customer interview.