Senior .NET / .NET Core Full Stack Developer (Modernization) jobs in United States
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Sansar Tec · 2 days ago

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

positionPhiladelphia, PA
timeContract
remoteOnsite
senioritySenior Level
date7+ years exp

Sansar Tec is seeking an experienced Senior .NET / .NET Core Full Stack Developer to lead the modernization of legacy .NET applications into a scalable, cloud-native .NET Core microservices and web portal ecosystem. The ideal candidate will be responsible for analyzing existing applications, modernizing web portals, and ensuring best practices in security and scalability throughout the modernization process.

Artificial Intelligence (AI)CRMEnterprise Resource Planning (ERP)Information Technology
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H1B Sponsor Likelynote
Hiring Manager
Venkat Kamisetti
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Responsibilities

Analyze existing legacy .NET applications and define modernization and migration strategies to .NET Core
Modernize and develop full-stack web portals and microservice-based components using .NET Core
Deeply understand existing MSSQL schemas, stored procedures, and business logic, and translate them to PostgreSQL with performance optimization
Perform database migration and transformation, including schema conversion, data migration, indexing, and tuning in PostgreSQL (AWS RDS)
Design and develop RESTful APIs ensuring scalability, modularity, and maintainability
Develop front-end components using modern JavaScript frameworks (React / Angular / Vue – details provided in SOW)
Collaborate with DevOps teams on AWS deployments, CI/CD pipelines, and environment automation
Ensure security, scalability, and cloud optimization best practices throughout the modernization process
Apply AWS Well-Architected Framework principles to deliver reliable and cost-effective solutions

Qualification

.NET CoreAWS servicesPostgreSQLMicroservicesRESTful APIsC#MSSQLEntity Framework CoreJavaScript frameworksDockerGitAgile / ScrumAnalytical skillsProblem-solvingCommunication skills

Required

7+ Years of experience
Deep expertise in .NET Framework, .NET Core, MSSQL
Hands-on experience migrating databases to PostgreSQL on AWS RDS
Strong exposure to AWS cloud services
Microservices architecture experience
Modern frontend frameworks experience
Analyze existing legacy .NET applications and define modernization and migration strategies to .NET Core
Modernize and develop full-stack web portals and microservice-based components using .NET Core
Deeply understand existing MSSQL schemas, stored procedures, and business logic, and translate them to PostgreSQL with performance optimization
Perform database migration and transformation, including schema conversion, data migration, indexing, and tuning in PostgreSQL (AWS RDS)
Design and develop RESTful APIs ensuring scalability, modularity, and maintainability
Develop front-end components using modern JavaScript frameworks (React / Angular / Vue)
Collaborate with DevOps teams on AWS deployments, CI/CD pipelines, and environment automation
Ensure security, scalability, and cloud optimization best practices throughout the modernization process
Apply AWS Well-Architected Framework principles to deliver reliable and cost-effective solutions
C#, .NET Framework, .NET Core, ASP.NET Core, Web API
Entity Framework Core
Strong expertise in MSSQL (stored procedures, triggers, functions, performance tuning)
Proven experience migrating MSSQL to PostgreSQL (data type mapping, query optimization, schema redesign)
Hands-on experience with PostgreSQL on AWS RDS
Microservices, RESTful APIs
Domain-Driven Design (DDD), Dependency Injection
AWS services: EC2, RDS, S3, CloudWatch, API Gateway, Lambda, ECS/EKS
Deploying and managing .NET Core applications on AWS
IAM roles, VPC configuration, and networking basics
Docker, CI/CD pipelines (GitHub Actions, Jenkins, AWS CodePipeline)
Git, GitHub
Swagger, Postman
xUnit / NUnit
Migration tools (AWS Schema Conversion Tool)
Strong analytical skills to understand and re-engineer legacy systems
Excellent problem-solving and debugging capabilities
Strong communication and stakeholder collaboration skills
Self-driven, ownership-oriented, and continuous learner

Preferred

AWS Certification (Developer Associate or Solutions Architect Associate)
Experience modernizing monolithic systems to cloud-native microservices
Experience with serverless (AWS Lambda) and API Gateway
Containerization experience (Docker, Kubernetes)
Data migration tools: AWS DMS, pgLoader, Flyway, Liquibase
Agile / Scrum development experience

Company

Sansar Tec

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Sansar Tec offers technology services and talent solutions, specializing in CRM, data, and AI.
dateFounded in 2015
location
Haddon Heights, New Jersey, USA
people-size11-50 employees
web-link
https://sansartec.com

H1B Sponsorship

Sansar Tec has a track record of offering H1B sponsorships. Please note that this does not guarantee sponsorship for this specific role. Below presents additional info for your reference. (Data Powered by US Department of Labor)
Distribution of Different Job Fields Receiving Sponsorship
Represents job field similar to this job
Trends of Total Sponsorships
2025 (19)
2024 (10)

Funding

Current Stage
Early Stage

Leadership Team

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Sarah Eberz
CEO
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Company data provided by crunchbase