Senior Backend .NET Core Developer

Senior Backend .NET Core Developer at Systems Arabia design, develop, and maintain secure, scalable backend services and financial technology platforms using C#, .NET Core / .NET 8+, and microservices architecture. Contribute to the development of core transaction processing engines, payment gateways, banking integrations, digital wallets, billing systems, and financial infrastructure, ensuring high availability, transaction reliability, security, and performance.

Responsibilities

Design, develop, and maintain scalable backend services and microservices using C#, .NET Core / .NET 8+, and RESTful APIs.Build high-performance transaction processing engines, payment pipelines, billing systems, and digital wallet solutions.Apply Clean Architecture, Domain-Driven Design (DDD), SOLID principles, and established software engineering best practices.Integrate payment gateways, banking APIs, POS systems, SADAD, acquiring banks, and direct host-to-host banking interfaces.Implement reliable payment processing workflows using fault tolerance, retries, idempotency, and transaction management mechanisms.Work with financial messaging standards and protocols, including ISO 8583, ISO 20022, and SWIFT.Design and implement double-entry accounting ledgers, escrow workflows, multi-party fund distribution, reconciliation, and bank settlement processes.Develop and maintain digital wallets, multi-currency transactions, account-to-account (A2A) transfers, and financial settlement solutions.Design, optimize, and maintain SQL Server / PostgreSQL databases using Entity Framework Core, ensuring data integrity and ACID compliance.Implement distributed caching and performance optimization using Redis.Develop asynchronous processing workflows, background services, and webhook integrations using RabbitMQ, Azure Service Bus, or Apache Kafka.Implement secure authentication, authorization, and data protection mechanisms using OAuth 2.0, tokenization, TLS, and sensitive data masking, aligned with PCI DSS requirements.Work with Docker, Kubernetes, and AWS / Azure to support containerized application deployment and cloud infrastructure.Write unit and integration tests; participate in code reviews, refactoring, and continuous improvement.Lead technical discussions, guide architecture decisions, mentor developers, and establish backend development best practices.Collaborate with Product, QA, and DevOps teams to deliver reliable financial technology solutions.Troubleshoot production issues and optimize transaction processing performance, scalability, security, and system reliability.

Requirements

7+ years of overall software development experience, including at least 3+ years of experience in financial, payment, or banking backend systems.Strong hands-on experience with C# and .NET Core / .NET 8+ backend application development.Solid experience designing and developing scalable microservices architectures and RESTful APIs.Strong understanding of Clean Architecture, Domain-Driven Design (DDD), SOLID principles, and software design patterns.Proven experience integrating payment gateways, banking APIs, POS systems, SADAD, acquiring banks, and financial platforms.Hands-on experience with financial messaging standards such as ISO 8583, ISO 20022, SWIFT, or direct host-to-host banking integrations.Strong understanding of financial systems, including double-entry accounting, ledgers, escrow, reconciliation, fund distribution, and bank settlements.Experience developing digital wallets, multi-currency transactions, A2A transfers, and payment processing systems.Strong experience with SQL Server / PostgreSQL, Entity Framework Core, database design, and query performance optimization.Good understanding of ACID transactions, data consistency, concurrency control, and distributed transaction management.Hands-on experience with Redis for caching and performance optimization.Experience implementing asynchronous processing and messaging solutions using at least one of RabbitMQ, Azure Service Bus, or Apache Kafka.Strong understanding of payment security and PCI DSS-aligned practices, including OAuth 2.0, tokenization, TLS, and sensitive data protection.Experience with Docker, Kubernetes, and cloud platforms such as AWS or Microsoft Azure.Understanding of unit testing, integration testing, code quality, and software development best practices.Experience with Git, code reviews, technical documentation, and collaborative development practices.Proven ability to lead technical discussions, mentor engineers, and contribute to architectural decisions.Strong analytical and problem-solving skills, with the ability to troubleshoot complex financial transaction and integration issues.