Senior ASP.NET Developer jobs in Seattle, WA

Hybrid in Bellevue, Washington

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3d ago

Greetings from LTM! Hope you are doing good. We are hiring Senior Software Engineer to join our digital engineering team. Who are we? LTM a Larsen & Toubro company is an AI-centric global technology services company and the Business Creativity partner to the worlds largest enterprises. Together with over 87,000 employees across 40 countries and our global network of partners, LTM owns business outcomes for our clients, helping them not just outperform the market, but to Outcreate it. Senior

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Full-time

100,000 - 110,000

Certified Microsoft .NET web Developer IV

Remote

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Today

Certified Microsoft .NET web Developer IV Primary Location: Madison, WI V-Soft Consulting is currently hiring for a Certified Microsoft .NET web Developer IV for our premier client in Madison, WI. Education and Experience Performs front-end and back-end development of web applications and web APIs (web services). (5-8+ years)Experience with ASP.net and SSRS reporting (5-8+ years)SQL Backend and stored procedure experience (5-8+ years)Development and Support experience on web-based applications

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Third Party, Contract

$63.38

L&I IT Application Development - Senior/Specialist

Remote or Tumwater, Washington

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Today

Salary : $99,300.00 - $133,608.00 Annually Location : Thurston County - Tumwater, WA Job Type: Full Time - Permanent Remote Employment: Remote Optional Job Number: 2026-08592 Department: Dept. of Labor & Industries Division: Information Technology Opening Date: 10/23/2026 Closing Date: 11/8/2026 11:59 PM Pacific Salary Information: The high end of the salary range, Step M is typically a longevity step Description Our Mission: Keep Washington Safe and Working!Our Values: Customer Focus, One L&I,

Full-time

USD 99,300.00 - 133,608.00 per year

Senior .NET Full Stack Developer - FHIR

Remote

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17d ago

Role: Senior .NET Full Stack Developer - FHIR Location: Remote Duration: 6+ months Job description: We are seeking a highly experienced Senior .NET Full Stack Developer with FHIR expertise to support a large-scale application modernization initiative. The ideal candidate will have strong hands-on experience in C#/.NET 8+, React, TypeScript, REST APIs, FHIR, microservices, Azure Cloud, and event-driven architecture. This is a hands-on technical leadership role involving modernization of le

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Contract

Depends on Experience

Senior .NET Developer :: Remote :: W2 Position

Remote

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Today

< data-pm-slice="1 3 []">Job Title: Senior .NET Developer Experience: 10+ Years Duration: 6+ Months (Possible Extension) Location: Dallas, TX Remote (Must be available for occasional travel to Dallas)<>Job Summary<>We are looking for an experienced Senior .NET Developer with 10+ years of experience in software development and production support. The ideal candidate should have strong expertise in Microsoft .NET technologies, C#, ASP.NET, .NET Core, Web API, and SQL Server, along with experience

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Contract

Depends on Experience

Senior .NET Web Developer (Certified) - REMOTE (WI Resident/MUST Relocate to WI)

Remote

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4d ago

Job Description: Crop to Crop resumes are accepted Location Requirement: Onsite, hybrid or remote: Candidates must be WI residents or willing to relocate to WI prior to starting the role. 100% remote work is an option. Can accommodate if candidate wants to work onsite. The Certified Microsoft .NET Web Developer IV is responsible for day-to-day maintenance of applications and support for business requests. The person in this role will manage integrations. This project requires knowledge of full

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Contract, Third Party

Depends on Experience

Senior .NET / EDI Developer (Healthcare) -- 100% Remote -- Only W2

Remote

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3d ago

Role : Senior .NET / EDI Developer (Healthcare) Location: Remote Key ResponsibilitiesDesign, develop, and maintain enterprise-grade applications using C#, .NET Framework/.NET Core/.NET 6+.Develop and support healthcare EDI transaction processing solutions.Implement, validate, and troubleshoot EDI X12 transactions including:837 (Claims)835 (Remittance Advice)834 (Enrollment)270/271 (Eligibility)276/277 (Claim Status)Build and maintain APIs, integration services, and backend processing systems.De

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Contract

Depends on Experience

Senior .Net Full Stack Developer

Remote

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5d ago

Job Description: Senior .NET Developer (11+ Years of Experience) Senior-Level PositionJob Title: Senior .NET Developer Experience: 11+ Years Employment Type: Contract W2 onlyJob SummaryWe are looking for a highly experienced Senior .NET Developer with 11+ years of hands-on experience in designing, developing, and maintaining enterprise-level applications using Microsoft .NET technologies. The ideal candidate should have strong expertise in C#, ASP.NET Core, Web API, SQL Server, and modern front-

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Contract

Depends on Experience

Senior Full Stack .NET Developer

Remote

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Today

Job Title: Senior Full Stack .NET Developer Job Location: Remote Job Type: Full Time Job Description: Develop scalable web applications using .NET and ASP.NET Core. Build responsive frontend applications using React or Angular with TypeScript. Develop REST APIs and backend services using C#. Work with Entity Framework Core, SQL Server, and Azure SQL. Integrate applications with external APIs and enterprise systems. Implement authentication, authorization, logging, caching, and error handling.

Full-time

Senior Backend .NET Developer

Remote

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Today

Job Title: Senior Backend .NET Developer Job Location: Remote Job Type: Full Time Job Description: Develop backend services and REST APIs using C# and .NET. Build business and domain logic using SOLID and Clean Architecture principles. Work with Entity Framework Core, LINQ, SQL Server, and Azure SQL. Design integrations with enterprise and third-party systems. Implement asynchronous processing, background services, and messaging. Work with Azure Service Bus and other messaging technologies. I

Full-time

Sr. .NET Developer

Remote or McLean, Virginia

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Today

Public Trust Eligibility Required About Aretum Aretum is a mission-driven organization committed to delivering innovative, technology-enabled solutions to our customers across defense, civilian, and homeland security sectors. Our teams work at the intersection of strategy, technology, and transformation, helping agencies solve their most critical challenges. We believe in investing in our people and creating a culture where collaboration, inclusion, and professional growth are at the forefront

Full-time

USD 120,000.00 - 150,000.00 per year

Senior .NET Developer – Azure / Microservices / AKS

Remote

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3d ago

Senior .NET Developer Azure / Microservices / AKS Company: Softthink Solutions Inc. (STSI) Position Type: Full-Time Location : Remote Position Overview Softthink Solutions Inc. (STSI) is seeking an experienced Senior .NET Developer to design, develop, modernize, and support enterprise web applications and cloud-native services. The ideal candidate will possess strong hands-on experience with C#, .NET, Microsoft Azure, Azure Kubernetes Service (AKS), RESTful APIs, microservices, and Azure SQL.

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Full-time

Depends on Experience

Senior .NET Developer (Billing Platform)

Remote

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13d ago

Role OverviewContribute to development of a billing/claims platform supporting high-volume transactional systems Build and scale backend services and enterprise applications Improve and evolve existing systems and architecture Design scalable, maintainable, and extensible solutions Participate across the full SDLC, including design, development, testing, and deployment Collaborate cross-functionally to translate business requirements into technical solutions Ensure code quality through test auto

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Full-time

Depends on Experience

Senior .NET Full Stack Engineer (Azure & Google Cloud Platform)

Remote

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13d ago

Senior .NET Full Stack Engineer (Azure & Google Cloud Platform) Remote | 12-Month Contract Location: Remote Duration: 12 months About the Role We re looking for a hands-on Senior Engineer to lead the design and delivery of cloud-native, AI-enabled enterprise applications. This is not a traditional .NET role: strong Azure and Google Cloud Platform engineering experience is required (AWS is not part of the environment). Key Responsibilities Lead development of enterprise applications across the fu

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Contract

Up to $65

IT Application Development - Senior/Specialist

Remote or Olympia, Washington

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Today

Salary: $99,300.00 - $133,608.00 Annually Location : Thurston County - Olympia, WA Job Type: Full Time - Permanent Remote Employment: Flexible/Hybrid Job Number: 2026-0195 Department: Board of Industrial Insurance Appeals Opening Date: 11/06/2026 Closing Date: 12/6/2026 11:59 PM Pacific Description This is an anticipated opening. The Board of Industrial Insurance Appeals (BIIA) is offering a challenging and rewarding opportunity for the right individual to make a difference through serving the s

Full-time

USD 99,300.00 - 133,608.00 per year

Senior .NET Software Engineer

Remote

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7d ago

Job Title: Senior .NET Software EngineerExperience: 6+ Years Mandatory Skills: .NET, C#, React, SQL Server Job DescriptionWe are looking for an experienced Senior .NET Software Engineer with strong expertise in .NET, C#, React, and SQL to develop, customize, implement, and support enterprise-level digital banking applications.The ideal candidate should have strong problem-solving skills, experience in client-facing technical roles, and the ability to deliver secure, scalable, and high-performan

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Full-time

Up to $135,000

.NET Developer Technical Lead

Remote

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13d ago

OverviewWe are looking for a hands-on Technical Lead and experienced .NET engineer to help lead the development of a newly formed Adherence Engineering Team. This team will design and build technology solutions that help medical practices improve patient vaccination adherence through targeted outreach and automation. Early pilot programs have already demonstrated strong results, showing over a 10% increase in vaccination rates when practices leverage patient outreach tools. This team will play a

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Full-time

Depends on Experience

Senior Web Developer

Tacoma, Washington

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Today

Company Overview At ValidaTek, we modernize and optimize IT services to solve some of the most critical challenges facing federal civilian and defense agencies. From customers to partners to top-talent employees, ValidaTek puts people first, empowering them to exceed expectations and transform government organizations. Our employees are building purpose-driven careers, not just filling jobs. We bring together people with many different perspectives, experiences, and talents to drive innovation

Full-time

Mobile Enterprise Platform, Team Lead

Tacoma, Washington

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Today

At ValidaTek, we modernize and optimize IT services to solve some of the most critical challenges facing federal civilian and defense agencies. From customers to partners to top-talent employees, ValidaTek puts people first, empowering them to exceed expectations and transform government organizations. Our employees are building purpose-driven careers, not just filling jobs. We bring together people with many different perspectives, experiences, and talents to drive innovation and achieve more t

Full-time

Senior .NET Developer / Cincinnati, OH/ Candidates - REMOTE

Remote or Cincinnati, Ohio

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Today

Greetings, We're seeking a Senior Full Stack Developer with strong backend expertise in .NET Core/.NET 8 and React.js on the frontend. Join a dynamic team building modern tech solutions for a leading financial and real estate client. Senior .NET Developer w/ React.js Application Developer Application Developer Cincinnati, OH - Hybrid Permanent IMPORTANT NOTE: This role requires the submission of a code exercise, which will take a senior developer 90 minutes (or longer) to complete. Please d

Full-time

Senior ASP.NET Developer jobs in Seattle, WA, USA