Backend .NET Engineer

Make your mark at Comcast -- a Fortune 30 global media and technology company. From the connectivity and platforms we provide, to the content and experiences we create, we reach hundreds of millions of customers, viewers, and guests worldwide. Become part of our award-winning technology team that turns big ideas into cutting-edge products, platforms, and solutions that our customers love. We create space to innovate, and we recognize, reward, and invest in your ideas, while ensuring you can proudly bring your authentic self to the workplace. Join us. You’ll do the best work of your career right here at Comcast. (In most cases, Comcast prefers to have employees on-site collaborating unless the team has been designated as virtual due to the nature of their work. If a position is listed with both office locations and virtual offerings, Comcast may be willing to consider candidates who live greater than 100 miles from the office for the remote option.)Job SummaryYou’ll join the engineering group delivering across three of our most visible program areas: the Managed Enterprise Services (MES) suite — spanning CCT, CBPC, Document Center, and EAC — the CBA side of AIX, and our Digital Convergence initiative (CVG / MA360). These are interconnected, business-critical applications, so the backend work here is high-leverage and highly visible.What makes this role compelling is how we build, not just what we build. We’re an early adopter of Spec-Driven Development (SDD) using OpenSpec: every change begins from a clear, version-controlled specification that the team — and our AI coding assistants — agree on before a line of code is written. Engineers here shape the spec, not just the implementation, which means less rework, a traceable decision history, and consistent patterns across a large, evolving codebase.As a backend engineer, you’ll own .NET services end-to-end — from authoring the spec to shipping and operating production code — while mentoring teammates and helping mature our SDD practice. If you enjoy modern .NET at real scale, an AI-augmented workflow, and being able to point to systems that matter, this is a strong fit.Job DescriptionResponsibilities:Author and refine OpenSpec artifacts — proposals, requirement specs, design notes, and task breakdowns — and implement against them as the source of truth.Design, build, and maintain backend services and APIs in C# / ASP.NET Core, including data access with SQL and Entity Framework Core.Use AI coding assistants effectively, driven by approved specs, to accelerate delivery without sacrificing quality.Write automated tests and ship through CI/CD pipelines; support deployment and operation of services in the cloud.Review peers’ specs and code, mentor less-experienced engineers, and help mature the team’s SDD practice.Collaborate with product, QA, and other engineering teams to translate ambiguous requirements into precise, buildable specifications.Collaborating with cross-functional teams to design, develop, and integrate innovative software solutions that align with business needsConducting analysis of system requirements and the customization of applications to ensure optimal functionalityAssisting with the software update process for existing applications and roll-outs of software releasesMentoring junior engineers, fostering a culture of technical excellence and shared knowledge within the teamEngaging with Quality Assurance to verify that software meets technical specifications and delivering high-quality, reliable applicationsTroubleshooting and resolving complex technical issues in software applications and systemsSynthesizing market research and industry trends to inform project strategies and enhance product offeringsConducting training sessions for operational staff to ensure effective use of internally developed applicationsConsistent exercise of independent judgment and discretion in matters of significance.Regular, consistent and punctual attendance.Other duties and responsibilities as assigned.Required qualifications5–7 years of professional backend software development.Strong, demonstrable proficiency in C# and the .NET stack (ASP.NET Core Web API).Experience designing REST APIs and working with relational databases (SQL, EF Core).Working knowledge of CI/CD, automated testing, version control (Git), and at least one cloud platform (Azure preferred).Comfort with — or strong aptitude for — spec-first / specification-driven workflows; direct OpenSpec or comparable SDD experience is a plus.Strong collaboration and communication skills. Able to effectively handle ambiguity well, provides thoughtful code feedback, and actively supports and mentors teammates to elevate overall team performance.Experience with AI-native development tools, such as OpenSpec or comparable frameworks (e.g., GitHub Spec Kit), with the ability to leverage these tools to drive efficient specification, development, and collaboration workflows.Employees at all levels are expected to:Understand our Operating Principles; make them the guidelines for how you do your job.Own the customer experience think and act in ways that put our customers first, give them seamless digital options at every touchpoint, and make them promoters of our products and services.Know your stuff be enthusiastic learners, users and advocates of our game-changing technology, products and services, especially our digital tools and experiences.Win as a team make big things happen by working together and being open to new ideas.Be an active part of the Net Promoter System a way of working that brings more employee and customer feedback into the company by joining huddles, making call backs and helping us elevate opportunities to do better for our customers.Drive results and growth.Support a culture of inclusion in how you work and lead.Do what's right for each other, our customers, investors and our communities.Disclaimer: This information has been designed to indicate the general nature and level of work performed by employees in this role. It is not designed to contain or be interpreted as a comprehensive inventory of all duties, responsibilities and qualifications.SkillsApplication Programming Interface (API), Artificial Intelligence (AI), Back-End Development, CI/CD, Collaboration, Microsoft .NETWe believe that benefits should connect you to the support you need when it matters most, and should help you care for those who matter most. That's why we provide an array of options, expert guidance and always-on tools that are personalized to meet the needs of your reality—to help support you physically, financially and emotionally through the big milestones and in your everyday life.Please visit the benefits summary on our careers site for more details.EducationBachelor's DegreeWhile possessing the stated degree is preferred, Comcast also may consider applicants who hold some combination of coursework and experience, or who have extensive related professional experience.Certifications (if applicable)Relevant Work Experience5-7 YearsComcast is an equal opportunity workplace. We will consider all qualified applicants for employment without regard to race, color, religion, age, sex, sexual orientation, gender identity, national origin, disability, veteran status, genetic information, or any other basis protected by applicable law.SummaryLocation: PA - Philadelphia, 1800 Arch StType: Full time