Internally, we're forming a dedicated tech team for a special project connected to our service operation in the banking industry. The main challenge is to build stable, scalable features that integrate seamlessly with our current ecosystem. The position exists because this new initiative requires strong technical ownership from day one. We are seeking senior backend platform engineer | cloud and machine learning to join a new, forward-thinking ai team, established in partnership in mexico city. Originally published on getonbrd.com. What you will do design, develop, and deploy ai-driven services and workflows ("agents") for the american express expense platform. Lead rag (retrieval-augmented generation) implementations, model fine-tuning, and production-ready llm workflows. Build features such as recommendations, predictions, dashboards analytics chatbots, and smart receipt generation. Ensure high standards for observability, testability, and metrics across ai models and systems. Collaborate in a fast-paced environment to deliver enterprise-grade solutions with a strong backend focus. Required skills & experience senior-level experience in delivering production-ready, scalable enterprise solutions. Senior full-stack engineer typescript. Strong backend engineering proficiency in golang (5 years) and react. Prior golang experience in non-ai contexts is acceptable; focus is on backend platform capabilities. Hands-on experience with llms, rag, fine-tuning, embeddings, and inference workloads. Proven experience building production ai systems (beyond prototypes) and strong knowledge of llm mechanics, neural networks, prompting, embeddings, and evaluation. Cloud infrastructure experience and practical ml knowledge relevant to backend platform engineering. Excellent professional-level english communication; experience collaborating with us-based teams is a strong plus. Experience implementing observability, testability, and metrics to support ai decision transparency. Technical ownership, autonomous execution, and the ability to work in fast-paced, ambiguous environments. Desirable skills experience with enterprise-scale data ecosystems and secure software practices. Familiarity with ai / ml model governance, versioning, and ab testing strategies. Exposure to production-grade monitoring and incident response for ai-driven workloads. Benefits competitive compensation and equity options. Hybrid work arrangement with monthly in-office collaboration in mexico city (1-2 days). Collaborative, global team with exposure to us-based partners. Career growth opportunities in ai / ml and backend platform engineering. Flexible work environment and strong emphasis on work-life balance. Hybrid this job is performed partly from home and partly at the office in ciudad de méxico (mexico). J-18808-ljbffr