Backend Developer (C# / .NET) — NXJ-209 w Warszawa, Polska

The Role

You will be joining our client’s Data Ingestion team, a highly focused group currently consisting of 5 developers, 1 QA, and 1 Product Manager. This is a newly created position due to team growth. The role is 90-95% backend-focused, with development time split evenly (approximately 50/50) between building new features and handling bug fixes/support.

Work Conditions:

• Location: Hybrid model in the Warsaw office (3 days per week on-site).
• Hours: Monday to Friday, approximately 9 AM to 6 PM (Core team often has quiet/non-working Fridays, making it a great day for deep work).
• Work/Life Balance: Regular hours with strictly no on-call duties.

About the Product

Our client’s platform transforms live sports broadcasts into personalized, publication-ready highlight packages while games are actively in progress. The system ingests live play-by-play game data, automatically analyzes and tags video streams to identify key moments, creates video highlights, and publishes content directly to platforms like YouTube. The system processes massive data volumes with zero tolerance for latency, directly powering downstream consumer-facing media products.

What You’ll Be Doing

High-Level Engineering

• Work independently to scope tasks, architect solutions, and lead technical initiatives without needing micromanagement.
• Apply strong system design and architecture principles to low-latency, event-driven microservices.
• Bridge ML models into production by building resilient deployment pipelines.
• Own end-to-end service delivery from initial RFC design through zero-downtime deployment and post-launch telemetry.
• Debug distributed performance bottlenecks and scale compute clusters handling concurrent 24/7 media processing.

Potential Daily Tasks

• Provider Integration: Analyze third-party REST APIs, write C#/.NET 8 ingestion managers and parsers, and configure JSON data mapping to internal MS SQL Server models (e.g., onboarding new leagues and clients).
• Pipeline Enhancement: Expand existing capabilities (such as rosters, coaching staff, and event lineups) and implement robust error-handling for edge cases where providers send malformed or unexpected data.
• Data Troubleshooting: Investigate production bugs by tracing data execution—comparing raw provider payloads in Azure Blob Storage against database records and Coralogix system logs.
• End-to-End Delivery: Drive the full software lifecycle within a monorepo architecture, handling active development, pull requests, code reviews, and deploying via GitHub Actions and Azure DevOps pipelines.
• Collaborative Design: Work closely with technical leads to refine solution architectures, proactively clarify Jira requirements, and document systems in Confluence within a highly responsive, knowledge-sharing team environment.

What We Expect

Must-have

• Experience Level: from 5 years of backend development experience.
• Tech Stack: Strong expertise in  C# and .NET Core 6+(preferably .NET 8).
• Architecture & Data: Solid hands-on experience with Microservices and SQL.
• System Design: Proven experience in system design and software architecture.
• Education: Formal university degree in Computer Science or a closely related technical field.
• AI Integration: Daily, hands-on experience using AI coding tools (such as Claude, Cursor, or ML frameworks) in your development workflow.
• Work Style: Highly independent, capable of scoping out complex tasks, and comfortable taking ownership without micromanagement.
• Track Record: A stable employment history demonstrating tenure (no frequent job hopping without legitimate reasons), ideally within established tech companies (preferred over banks or very small startups where senior mentorship was lacking).

Nice-to-have

• Experience with messaging queues, event-driven architecture, and modern design patterns.
• Full-stack capabilities or some frontend development experience.
• Cloud infrastructure experience, preferably Azure (though AWS and GCP are perfectly acceptable).

Why This Role Is Worth Your Time

• Impact: Direct ownership of high-concurrency event pipelines where code changes instantly impact live, broadcast-level media products published to global audiences.
• Modern AI Practices: Pragmatic adoption of AI engineering practices — AI coding assistants (Claude) are an expected, integrated part of our client’s production workflows.
• Great Work-Life Balance: Complex distributed systems engineering without the burnout—enjoy a predictable Monday-Friday schedule with zero on-call responsibilities.