Senior Backend developer (C# ) at ARHS


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ARHS is Hiring

Job Info:
  • Company ARHS
  • Position Senior Backend developer (C# )
  • Location Warsaw, Poland
  • Source SmartRecruiters
  • Published July 17, 2025
  • Category Development
  • Type Full-Time
  • Experience Senior


Job Description

 

We are seeking a Senior Backend Engineer to design, develop, and optimize backend microservices in a large-scale, cloud-based environment. Leveraging Domain-Driven Design (DDD), you will define bounded contexts aligned with business domains, ensuring scalable, resilient, and maintainable architectures. You'll work closely with cross-functional teams, including architects, project managers, analysts, frontend developers, and ICT support teams to deliver high-quality solutions aligned with both business and technical goals.

Key Responsibilities:

  • Architecture & Development:

    • Lead the design and implementation of scalable, high-performance microservices using DDD.

    • Decompose monolith applications into modular, independently deployable services.

    • Design and document secure REST and WebSocket-based APIs.

    • Implement token-based authentication (e.g., JWT, OAuth2) to secure backend systems.

    • Optimize applications for performance, scalability, and cost-effective deployment in cloud platforms (Azure, AWS).

  • Collaboration & Leadership:

    • Collaborate with the Architecture Team, Business Capability Sector, and Application Support to align solutions with enterprise standards.

    • Work closely with frontend engineers to ensure seamless API integration and aligned response structures.

    • Mentor junior developers and lead Agile ceremonies, promoting DevOps best practices and continuous improvement.

  • Analysis & Documentation:

    • Translate business requirements into technical designs in collaboration with architects and analysts.

    • Prepare and maintain HLA, HLD, and LLD documentation or equivalent Agile artifacts (e.g., user stories).

    • Document microservice designs, including functionality, dependencies, API specs, and deployment guides.

  • Quality Assurance & Performance:

    • Conduct code reviews to enforce standards, improve quality, and provide feedback.

    • Analyze backend services to identify and eliminate bottlenecks through refactoring and optimization.

    • Implement performance testing, load balancing, and caching strategies to ensure robust performance.

  • Strategic Contributions:

    • Define microservice boundaries using DDD.

    • Contribute to backend architecture evolution and continuous documentation practices.

    • Identify and mitigate risks related to integration, scalability, performance, and security.

Key Performance Indicators:

  • Speed & Responsiveness: Ability to rapidly adapt to changing requirements and deliver updates swiftly.
  • Timeliness: Meet agreed timelines and delivery milestones.
  • Code Quality: Maintain high standards in software development, documentation, and testing.
  • Efficiency: Optimal use of resources to deliver effective solutions.
  • Standards Compliance: Adherence to internal and industry best practices.
  • Team Leadership: Facilitate Agile development practices and foster team learning and cohesion.

Mandatory:

  • Bachelor's degree in Software Engineering
  • Minimum English language skills at the Level B2
  • Minimum 5 years of experience, including the responsibility to design and build complex microservices for a large organization.
  • Deep knowledge of building microservices and understanding of architectural patterns such as orchestration and choreography (SAGA) using the Domain Driven Design approach.
  • Develop, implement, and maintain scalable and loosely coupled microservices.
  • Build and deploy high-quality APIs (REST / WebSockets based) to connect services and support external integrations.
  • Expertise with containerization (Docker) and orchestration (Kubernetes).
  • Strong programming skills in C#.
  • Writes specifications, concept documents, end-user and technical documentation; communicates effectively with stakeholders on technical and user requirements topics
  • Well-developed interpersonal skills.
  • Ability to work in a team, demonstrating strong communication skills and a willingness to share knowledge.
  • Previous experience working in an Agile team (SCRUM).
  • Designing and implementing solutions based on microservices architecture.
  • Creating technical documentation and conducting code reviews.

Desirable:

  • Practical knowledge of the Red Hat OpenShift platform (RHOS). 
  • Knowledge of Git Workflows.
  • Ability to create automated, unit and integration tests.
  • Establish and maintain CI/CD pipelines for microservices deployment.
  • Implement monitoring, logging, and distributed tracing tools (e.g., Prometheus, Grafana, ELK, Jaeger) with a Service Mesh communication layer.
  • Ensure system security through token-based authentication (JWT, OAuth2) and other measures.
  • Deep knowledge of design patterns like Service Discovery, Circuit Breaker, and API Gateway (preferred KONG).
  • Proficiency with cloud platforms (Azure, AWS) and associated tools.
  • Hands-on experience with asynchronous messaging systems (Kafka based).
  • Familiarity with distributed databases and data management strategies (SQL/ NoSQL).
  • Proficient in implementing event-driven architecture (EDA) based on Kafka.
  • Write clean, efficient, and maintainable code
  • Practical knowledge of working in a CI / CD environment based on Azure DevOps.
  • Experience in building observability for microservices.
  • Knowledge of UML notation.
  • Works independently and guide junior staff.
  • SOLID understanding of best practices, processes and patterns in software development.
  • Working with frontend and backend teams to deliver consistent solutions.
  • Optimizing applications for performance and scalability.