C# Developer Mid/Senior

We are looking for a motivated .NET Developer to join our cross-functional team and contribute to the delivery of robust, cloud-native features for our platform. You’ll work alongside Solution Architects, Product Owners, Developers, DevOps engineers, and QA Automation Engineers to build scalable backend solutions and services. This role is ideal for someone who is technically curious, values clean and secure code, and enjoys working collaboratively in an Agile environment. Key Accountabilities: Collaborate with Solution Architects, Product Owners, Developers, DevOps and QA Automation Engineers to contribute to the development and delivery of new product features using the following technologies: Languages: C#, .NET, Typescript Databases: AWS Aurora PostgreSQL, AWS DynamoDB, MongoDB, AWS DocumentDB, AWS ElastiCache Redis Cloud Infrastructure: AWS (API Gateway, Fargate, SQS, SNS, KMS, SecretManager, Cognito, Lambda (Python), etc), Localstack, Docker Analyse business requirements, internal designs and non-functional requirements and estimate user stories collaboratively with the team. Follow industry best practices, coding guidelines and secure development practices, and ensure other members of the team do likewise. Understand and maintaining awareness of technology, software design and development methodology trends and contribute to strategy through the suggestions of suitable solutions to meet business / product needs. Follow lean/agile principles and help to continually improve processes and practices Required Skills Professional level:2+ years' experience- Mid or 5 years+ -Senior, as a Developer within a modern software environment C# with .NET (latest LTS) Strong Web API experience Minimal APIs for lightweight, high-performance endpoints MassTransit for message-based communication and integration with message brokers like RabbitMQ or Azure Service Bus MediatR to promote clean separation of concerns through in-process messaging (CQRS-style) Domain-Driven Design (DDD) principles to model complex business domains Event-Driven Architecture with asynchronous messaging and integration Asynchronous programming throughout for responsiveness and scalability, multi-threaded & parallel programming Strong experience in SQL & NoSQL databases Experience in improving, refactoring, and rewriting code Understanding of design patterns Experience using CI/CD build and deployment pipelines. Experience in secure coding practices, OWASP Top 10, etc. Required behaviors and attributes: Excellent knowledge of software development methodologies and techniques Strong analytical and problem-solving skills Attention to detail Optional / Nice-to-Have Skills : Payment industry experience is advantageous Experience with CQRS would be advantageous Hybrid work from Cracow with a minimum of 1 day per week is preferred here, but the client will consider fully remote working candidates as well.