Senior .NET Developer, Colombia

At CI&T, we help large enterprises transform the potential of AI into real business impact with AI Deployment, AI-native execution, and tech-integrated business solutions. With 30 years of experience in technological transformation, we accelerate innovation with expertise in Agentic SDLC, Application modernization, Data & AI, Martech and Business strategy. We are 8,000 CI&Ters across more than 25 countries, collaborating to build solutions with real impact. AI is already part of how we work, evolve, and innovate every day. We are looking for a Senior .NET Engineer to join our team and drive the development and integration of complex back-end software solutions. You will work closely with a multicultural team distributed across Brazil, Colombia, the UK, and the USA, collaborating daily in English and contributing to robust, scalable services and integrations. Must-Have Skills: .NET Experience: strong experience with .NET Framework and .NET Core in production systems Backend Development: hands-on experience building back-end services with C#, ADO.NET, and SQL Server APIs & Integration: solid experience implementing and evolving SOAP and RESTful services, including versioning and best practices Data & Persistence: strong understanding of ADO.NET, SQL Server, database design and performance tuning XML: proficiency in XML serialization/deserialization Software Design: solid grasp of software design patterns and engineering best practices Testing & Reliability: experience with unit and integration testing, troubleshooting and root-cause analysis for service reliability Communication: effective communication skills in multicultural, fast-paced environments Language: advanced English proficiency (all communication in English). Key Responsibilities Design, build and maintain back-end services using C#, ADO.NET and SQL Server Implement and evolve SOAP and REST APIs, ensuring proper versioning, security and best-practice standards Ensure service reliability through unit and integration tests, troubleshooting, monitoring and root-cause analysis Collaborate on integration between multiple systems and services, applying appropriate software design patterns Conduct code reviews, provide technical feedback and mentor junior engineers Stay current with emerging technologies and industry trends, applying them to improve existing solutions Contribute to CI/CD workflows and best practices to increase development efficiency and deployment quality Soft Skills Ownership & Continuous Improvement: proactive in taking responsibility for tasks and driving improvements Communication: able to clearly explain complex technical topics to both technical and non-technical audiences Collaboration: team player who values shared success and cross-functional collaboration Adaptability: comfortable navigating ambiguity and shifting requirements in a dynamic environment Nice-to-Have Skills Cloud: experience with cloud platforms, preferably Microsoft Azure Modern Practices: familiarity with specification-driven development and agentic approaches to software development Agile: exposure to Agile methodologies (Scrum, Kanban, etc.) The successful candidate will deliver reliable, performant back-end services and integrations, help elevate engineering standards through reviews and mentorship, and collaborate smoothly across time zones and cultures using English as the primary language. If you are a seasoned back-end developer ready for complex challenges in a dynamic, multicultural environment, we invite you to apply and become part of our diverse team! Our benefits include: - Premium Healthcare - Meal voucher - Maternity and Parental leaves - Mobile services subsidy - Sick pay-Life insurance - CI&T University - Colombian Holidays - Paid Vacations And many others. Collaboration is our superpower, diversity unites us, and excellence is our standard. We value diverse identities and life experiences, fostering a diverse, inclusive, and safe work environment. We encourage applications from diverse and underrepresented groups to our job positions.