Senior Full-Stack Engineer C#

About Us Coderio designs and delivers scalable digital solutions for global companies. We combine strong technical expertise with a product mindset to lead complex software initiatives end-to-end. We work with international clients, value autonomy and clear communication, and build long-term partnerships through technical excellence.  🔗 More information: http://coderio.com The Project We are looking for a Senior Full-Stack Engineer to join a three-person team at a leading financial institution. The project replaces a legacy system of 16 workflows: a web portal where branch users submit requests, and a backend that sends them to other systems, receives responses, updates statuses and manages approvals. Delivery dates are aggressive, so we need someone who can contribute quickly after onboarding. Responsibilities Design and build backend services in C# / .NET, applying clean architecture and engineering best practices. Deliver features end to end: APIs, integrations with other systems, approval-workflow logic and the React web portal. Work in an Agile team with two-week sprints and the usual ceremonies. Answer teammates' technical questions and take part in code reviews. Write and maintain unit and regression tests. Document technical decisions and collaborate with business stakeholders and teams that own other systems. Requirements 5+ years of hands-on software development experience in C# / .NET (7+ preferred), building applications rather than only maintaining them. Applied knowledge of clean architecture: SOLID principles, separation of concerns (SRP), DRY and domain-driven design. Proven experience building an application from scratch. Working knowledge of React and CSS (no UI design specialization required). Experience writing unit and regression tests. Experience working in Agile / Scrum teams. Strong in-person communication, teamwork and the ability to adapt to a corporate environment. Ability to work in a hybrid model from the Miami Lakes, FL office. Professional level of English [confirm with the client]. Nice to Have Experience in banking or financial services. Experience integrating systems through REST APIs and messaging. Experience with workflow and approval processes. Familiarity with UI templates such as Mantis. A genuine passion for programming and for tackling a challenging, high-volume project. Benefits Hybrid collaboration in a dynamic and fast-paced environment in the Miami / Fort Lauderdale area. Long-term contract engagement with high impact and autonomy. Strategic and high-visibility role within a modern engineering culture. Opportunity to influence technical strategy, especially regarding modern event-driven architectures and AI integrations. Collaborative international team with strong technical leadership. Why Join Coderio? At Coderio, we value talent and excellence. While we are primarily a remote-first company, this specific strategic role offers the opportunity to work directly on-site to drive high-stakes initiatives. We are passionate about technology, collaboration, and fair compensation. We offer an inclusive and challenging environment with real growth opportunities. If you are motivated to design solutions that make a difference, we are waiting for you. Apply now.