Position: Senior Backend .NET Core Developer About us: We develop smart, sustainable, and scalable digital solutions that help organizations simplify and manage business processes efficiently and effectively, transform data into decisions, and unlock new opportunities for growth and innovation. Website: www.lamdax.sa Role Overview We are seeking a Senior Backend .NET Core Developer to design and implement highly scalable microservices using Domain-Driven Design (DDD), event-driven architectures, and gRPC APIs. You’ll build performance, secure data layers with EF Core and MS SQL Server, integrate robust authentication/authorization, and drive best practices across the team. · Architect & develop microservices – apply DDD to define bounded contexts and aggregates; implement CQRS; build modular .NET Core services · Design event-driven solutions – implement publish/subscribe workflows with RabbitMQ/Azure Service Bus/Kafka; handle event contracts, serialization, idempotency · Build gRPC APIs – define protobuf contracts, service definitions, versioning; optimize bidirectional and streaming calls for low latency · Optimize data access & performance – model schemas in MS SQL Server; tune EF Core queries; profile and resolve bottlenecks (caching, indexing, async patterns) · Enforce security & compliance – integrate JWT, OAuth 2.0/OpenID Connect (OpenIddict/IdentityServer); apply secure coding practices, encryption, secrets management · Collaborate & mentor – partner with Product Owners, QA, Front-end, and Mobile teams to clarify requirements; lead code reviews and share best practices · Estimate & plan – provide high-level effort estimates with strong accuracy and adjust plans under pressure Required Qualifications · Bachelor’s in Computer Science/Engineering or equivalent · 6+ years hands-on .NET Core and C# experience; deep understanding of both .NET Framework and .NET Core · Deep understanding of microservices and distributed systems programming models · Proven background in event-driven architectures (pub/sub, event sourcing) · Strong proficiency with gRPC and protobuf · Expert with Entity Framework Core and MS SQL Server (T-SQL, indexing, migrations) · Solid experience with authentication & authorization frameworks (JWT, OAuth2, OpenID Connect) · Strong knowledge of GOF design patterns and SOLID principles · Strong understanding of network fundamentals (HTTP, TCP/IP) · Demonstrated ability to profile and optimize high-throughput services · Strong experience with multithreading programming models · Excellent analytical, problem-solving, estimation, and communication skills · Agility and ability to work effectively under pressure while keeping commitments