Welcome to the 3rd International Conference on Sustainable Engineering, Infrastructure, and Development (ICO-SEID 2026), hosted by the Faculty of Industrial Technology and Faculty of Infrastructure Planning, Universitas Pertamina, Indonesia. Held in Jakarta on November 11–12, 2026, the conference brings together academics, industry professionals, and policymakers to exchange ideas and advancements in sustainable engineering, infrastructure, and development. The theme of ICO-SEID 2026 is: “Engineering Innovation for Energy Transition, Climate Resilience, and Sustainable Development.”