Sr. Software Development Engineer, MONA

About the role

AWS runs one of the largest networks in the world, and MONA (Management, Out-of-Band Networks, and Automation) alone owns over one million physical devices across its full lifecycle. We are in the critical path for every new data center powering the AI revolution. We build the in-house software that solves our hardest network business problems — controllers, software-defined networking (SDN), and planning systems. For example, we own a controller for agentic network auto-remediation, and the planning software that plans every new data center down to capacity and ports. We are looking for a Senior Software Development Engineer to be a technical leader and force multiplier: you will partner with the engineering manager to shape our software strategy while continuing to design and build these systems at fleet scale. If you want the scope to influence what we build and how we build it — and to keep building it yourself — this is that role. Key job responsibilities - Partner with the engineering manager to shape the team's software strategy — architecture, roadmap, and long-term vision — for the in-house systems behind a 1M+ device network (everything we run, we build ourselves). - Design and build the in-house systems that solve our business problems — controllers, software-defined networking (SDN), and planning software — end-to-end, architected to scale with robust tests and metrics. - Own and evolve our controller for agentic network auto-remediation that detects and resolves network issues automatically. - Build the planning software that plans every new data center — capacity, racks, and ports — and deploys new network fabric. - Own out-of-band management-plane services: serial console access to every server and router, plus managed connectivity such as SSH. - Drive correctness and safety for automation acting on production networks: idempotency, guardrails, and observability that proves work actually happened. - Lead design reviews, raise the operational-excellence and code-quality bar, and mentor engineers. - Participate in on-call and help lead high-severity incident response. A day in the life No two days look the same. One morning you are whiteboarding with the manager and a principal engineer on how to evolve the control plane for the next wave of AI data centers; the next you are deep in a greenfield auto-remediation service that resolves faults automatically instead of paging a human at 3am. You will make a teammate's design better, unblock a data-center build with capacity planning, and harden out-of-band console access to a million devices. You will see your work land at a scale almost nowhere else can offer — with real autonomy and teammates sharp enough to make you better. About the team MONA (Management, Out-of-Band Networks, and Automation) is part of AWS Core Networking. We are a highly motivated team of software, systems, and network developers who thrive on solving challenging problems and building large-scale distributed systems. AWS runs one of the largest networks in the world, and MONA alone owns the full lifecycle of over a million physical devices — driving new innovation in one of the largest data center networks on Earth. Everything we run we build in-house: controllers, software-defined networking, planning software, etc.
- 7+ years of non-internship professional software development experience - 7+ years of programming with at least one software programming language experience - 7+ years of leading design or architecture (design patterns, reliability and scaling) of new and existing systems experience - Experience as a mentor, tech lead or leading an engineering team