Senior Backend Developer (.NET, Azure)

Quick Facts

• Role: Senior Backend Developer (.NET, Azure)

• Focus: Backend services, APIs, and financial data processing workflows

Description

Senior Backend Developer responsible for designing and building backend services using C#/.NET on Azure for a wealth management data SaaS platform. You will make architectural decisions, apply DDD to model business domains and contracts, modernize existing solutions, and lead complex work from requirements to production operations. The role includes using AI throughout the development lifecycle while critically validating AI-generated outputs for correctness, security, and architectural alignment.

Responsibilities

• Design and develop backend services using C#/.NET on Azure

• Design domain models using DDD, including boundaries, responsibilities, and component contracts

• Design APIs, integrations, and financial data processing workflows with a focus on correctness, performance, reliability, and security

• Make architectural decisions and evaluate trade-offs

• Modernize existing solutions and improve overall architecture quality

• Lead complex end-to-end topics from analysis and implementation through deployment and production operation

• Diagnose complex production issues and decide on corrective actions

• Use AI across the software development lifecycle and validate AI-generated results

• Collaborate with AI Engineers to design and integrate AI-powered functionality with backend services

• Collaborate with Product, QA, DevOps, and other engineers

• Support engineers through code reviews, knowledge sharing, and technical problem-solving

• Contribute to technical standards and continuous improvement of engineering practices

Requirements

• 5+ years of experience developing backend applications with C#/.NET

• Strong knowledge of C#/.NET including designing components and production-grade solutions

• Strong experience with SQL / SQL Server / Azure SQL: data modeling, query optimization, diagnosing performance issues

• Strong knowledge of REST APIs / HTTP: contract design, versioning, compatibility, secure integrations

• Practical experience with DDD, SOLID, and design patterns, including defining domain boundaries

• Experience with Azure App Service and Azure Functions

• Experience with Azure Service Bus and asynchronous communication

• Strong knowledge of Git and Azure DevOps / CI/CD

• Experience with unit and integration testing and testable architecture

• Experience with monitoring and production troubleshooting using logs and Application Insights

• Experience with Azure Storage / Key Vault and understanding secrets management

• Experience with caching solutions such as Redis and understanding their impact on data consistency

• Professional proficiency in English (spoken and written) and Polish

Benefits

• Flat organizational structure with fast decision-making and minimal bureaucracy

• Opportunity to work on innovative, tech-driven projects in the financial sector

• Private medical care (Medicover) and Multisport card

• Strong team culture with integration events, offsites, and regular team lunches

• Flexible working hours with hybrid/remote setup; minimum 8 days in office per quarter (or more depending on team needs)