About the role Commit builds software products for clients across embedded, IoT, SaaS, AI/ML, e-commerce, mobile, and web. We’re looking for a Senior System Engineer with a strong mobile focus to sit at the intersection of analysis, design, and hands-on delivery — turning business and system requirements into clear architecture and detailed design, then helping build it. You’ll analyze requirements, own the High Level Design (HLD) and Low Level Design (LLD) — including mobile app architecture — and stay hands-on (~50% of your time) as a full-stack developer across a React, Node.js, React Native, and .NET stack, with React Native and mobile at its core. You’ll partner directly with clients (including large enterprise and banking environments). What you’ll do Analyze system and business requirements — elicit, clarify, and structure them into clear, complete, and testable specifications. Own the High Level Design (HLD), including mobile app architecture: system structure, components, integrations, data flows, and non-functional requirements. Produce the Low Level Design (LLD): detailed module and API design, data models, and sequence flows, ready for implementation. Stay hands-on (~50%): write production code full-stack — React, Node.js, .NET (C#), and React Native — with mobile at the center of what you build. Partner with product, architects, developers, and QA to translate designs into delivery and keep requirements, design, and implementation aligned. Uphold engineering standards: code reviews, testing, and secure-by-design practices across the solution.