Senior Fullstack Developer (React & .NET Core)

About the Role

Senior Full Stack Developer with strong React frontend and C# .NET Core backend experience. Build scalable, cloud-native apps for capital markets with focus on credit risk and market risk. Practical experience with Python (pyspark), CI/CD, microservices, and event-driven architectures is required.

Key Responsibilities

• Develop and maintain full stack apps using React and C#.NET Core.
• Implement high-performance backend services, REST APIs and microservices.
• Create responsive, modular UI components (JS/TS).
• Collaborate with stakeholders and risk domain experts on credit risk and market risk solutions.
• Use Python (pyspark) for data pipelines and transformations.
• Maintain and optimize Power BI dashboards and data models.
• Implement and improve CI/CD pipelines, automated testing and monitoring.
• Design event-driven and distributed systems (Kafka, Event Hub, etc.).
• Drive best practices: code reviews, tests, performance tuning, docs.
• Support cloud migration and modernization (Azure, AWS).
• Mentor junior developers in an agile, cross-functional team.

Offer:

• Location: Poland, remote (equipment pickup in Warsaw/Wrocław).
• Zatrudnienie: przez apreel na zasadach B2B.
• Start: asap.
• Rate: up to 155 zł netto/h.

Required Skills & Experience

Technical Skills

• 10+ years of professional software development.
• Front-end: React.js, JavaScript/TypeScript, Redux/RTK, hooks, modern UI patterns.
• Back-end: C# .NET Core, C#, REST/Web APIs, microservices.
• Python (pyspark): distributed data processing, data pipelines, analytic transformations.
• Power BI: dashboards, data models, DAX, performance tuning, governance.
• Architecture: microservices, API design, event-driven architectures, distributed systems.
• DevOps / CI/CD: Azure DevOps, GitHub Actions, Jenkins (or similar); automated builds, testing, deployment, monitoring.
• Cloud Platforms: Azure or AWS (Azure preferred).
• Databases: SQL Server, PostgreSQL, other relational DBs; NoSQL a plus.
• Containerization: Docker, Kubernetes, container orchestration.

Domain Knowledge

• Understanding of capital markets.
• Credit risk: PD, LGD, EAD, credit exposure modeling, counterparty risk.
• Market risk: VaR, sensitivities, stress testing, pricing concepts.
• Familiarity with regulatory frameworks (Basel, FRTB, IFRS9) is an advantage