Senior .NET / .NET Core Full Stack Developer (Modernization)

Job Title: Senior .NET / .NET Core Full Stack Developer (Modernization) Location: Philadelphia, PAMode: Contract Domain: Telecom Domain Mandatory Experience: 7 years Overview We are looking for an experienced Full Stack Developer with a strong background in both .NET Framework and .NET Core, who can drive the modernization of legacy .NET applications into a scalable .NET Core microservices and web portal ecosystem. The ideal candidate should have a deep understanding of MSSQL databases, be capable of translating and optimizing them into PostgreSQL (AWS RDS), and ensure smooth migration and integration across application layers, along with hands-on experience with AWS cloud deployment, microservices architecture. Key Responsibilities • Analyse existing legacy .NET applications and define a modernization and migration strategy to .NET Core.• Develop and modernize both full-stack web portals and microservice-based components using .NET Core.• Deeply understand existing MSSQL schema, stored procedures, and business logic, and effectively translate them to PostgreSQL, optimizing for performance and compatibility. • Handle database migration and transformation — including schema conversion, data migration, indexing, and tuning in PostgreSQL (AWS RDS).• Design and build RESTful APIs and backend services, ensuring modularity and maintainability. • Implement front-end components using modern JavaScript frameworks (React / Angular / Vue). [Will get more information with SOW] • Collaborate with DevOps for AWS-based deployment, CI/CD pipeline setup, and environment automation. • Ensure best practices in security, scalability, and cloud optimization throughout the modernization process. • Apply AWS Well-Architected Framework principles for reliable and cost-efficient cloud solutions. Technical Skills Required• Backend: C#, .NET Framework, .NET Core, ASP.NET Core, Web API, Entity Framework Core. • Frontend: React / Angular / Vue (any modern JavaScript framework). • Database:o Strong expertise in MSSQL — including stored procedures, triggers, functions, and performance tuning. o Proven experience in translating MSSQL to PostgreSQL, including data type mapping, query optimization, and schema redesign.o Hands-on experience with PostgreSQL on AWS RDS. • Architecture: Microservices, RESTful APIs, Domain-Driven Design, Dependency Injection.• Cloud & DevOps:o Strong working knowledge of AWS services: EC2, RDS, S3, CloudWatch, API Gateway, Lambda, ECS/EKS. o Experience deploying and managing .NET Core applications on AWS. o Familiarity with IAM roles, VPC configuration, and networking basics. o Experienced with with Docker, CI/CD (GitHub Actions, Jenkins, AWS CodePipeline). • Version Control: Git, GitHub. • Testing & Tools: Swagger / Postman, xUnit / NUnit, migration tools (e.g., AWS Schema Conversion Tool). Preferred: • AWS Certification (Developer Associate / Solutions Architect Associate). • Experience in modernizing monolithic systems to cloud-native microservices. • Experienced with serverless (AWS Lambda) and API Gateway integrations. • Familiarity with containerization (Docker, Kubernetes). • Experience with data migration utilities (AWS DMS, pgLoader, Flyway, Liquibase). • Knowledge of Agile/Scrum development processes. Soft Skills: • Strong analytical ability to understand legacy codebases and re-engineer them effectively. • Excellent problem-solving and debugging skills across both application and database layers. • Strong communication skills to work with cross-functional teams and stakeholders.• Self-driven and ownership-oriented with a continuous learning mindset. Requirements:Analyse existing legacy .NET applications and define a modernization and migration strategy to .NET Core.• Develop and modernize both full-stack web portals and microservice-based components using .NET Core.• Deeply understand existing MSSQL schema, stored procedures, and business logic, and effectively translate them to PostgreSQL, optimizing for performance and compatibility. • Handle database migration and transformation — including schema conversion, data migration, indexing, and tuning in PostgreSQL (AWS RDS).AWS Certification (Developer Associate / Solutions Architect Associate). Experience in modernizing monolithic systems to cloud-native microservices. • Database:o Strong expertise in MSSQL — including stored procedures, triggers, functions, and performance tuning. o Proven experience in translating MSSQL to PostgreSQL, including data type mapping, query optimization, and schema redesign.o Hands-on experience with PostgreSQL on AWS RDS.