Senior Software Engineer

Description Overview Our client is seeking a Senior Backend Engineer with deep expertise in OAuth 2.0, Auth0, and backend development using .NET (C#) and PHP. This engineer will help design and implement identity, authorization, and reseller-channel features within a distributed, multi-tenant architecture. This is a hands-on development role requiring strong systems-level thinking and experience building secure, scalable, service-oriented systems. Key Responsibilities + Design and implement OAuth 2.0 authentication/authorization flows. + Integrate clientu2019s platform with Auth0 (Okta), including identity provider configuration. + Develop backend services using .NET (C#) and PHP. + Support microservices and distributed systems architecture efforts. + Model complex reseller / channel-partner ecosystems and access patterns. + Contribute to platform-wide security, API design, and hierarchical access models. + Assist in implementing white-label, multi-tier, and multi-tenant system features. + Collaborate with engineering leadership during an accelerated implementation window (Auth0 rollout through April 1). Requirements Top 3 Required Skills + OAuth 2.0 protocol design & implementation; strong experience integrating with Auth0 + Backend development in .NET (C#) and PHP + Reseller / channel-partner system modeling Required Experience + Senior-level engineering background (backend-focused). + .NET (C#) and PHP development. + Microservice and distributed systems design. + OAuth 2.0 and authentication/authorization architecture. + API security, token handling, and identity workflows. + Multi-tenant platform engineering. + White-label and hierarchical access control patterns. + Usage-based billing or multi-tier rating systems. + Systems-level design awareness. Nice to Have: + Auth0/Okta hands-on integration experience + React or light frontend experience + Industry experience with MSP or telecom platforms Technology Doesn't Change the World, People Do.u00ae Robert Half is the worldu2019s first and largest specialized talent solutions firm that connects highly qualified job seekers to opportunities at great companies. We offer contract, temporary and permanent placement solutions for finance and accounting, technology, marketing and creative, legal, and administrative and customer support roles. Robert Half works to put you in the best position to succeed. We provide access to top jobs, competitive compensation and benefits, and free online training. Stay on top of every opportunity - whenever you choose - even on the go. Download the Robert Half app ( and get 1-tap apply, notifications of AI-matched jobs, and much more. All applicants applying for U.S. job openings must be legally authorized to work in the United States. Benefits are available to contract/temporary professionals, including medical, vision, dental, and life and disability insurance. Hired contract/temporary professionals are also eligible to enroll in our company 401(k) plan. Visit roberthalf.gobenefits.net for more information. u00a9 2025 Robert Half. An Equal Opportunity Employer. M/F/Disability/Veterans. By clicking u201cApply Now,u201d youu2019re agreeing to Robert Halfu2019s Terms of Use ( and Privacy Notice (.

Created: 2026-02-16