This study adopts the complexity theory framework to examine the facilitation of teacher learning at the school levels in Singapore from the perspective of the School Staff Developers (SSDs). With the decentralisation of teacher professional learning to the local levels, this article examines how leaders appointed to lead teacher learning within schools negotiate the tensions, challenges, and opportunities. To understand the phenomenon of teacher learning at the school level, this study adopted autoethnography to describe and analyse the personal experience of SSDs engaged in planning and facilitating teacher learning. Findings revealed the dynamics of decentralisation faced by the SSDs and identified three perspectives in negotiating the challenges, tensions, and opportunities: (a) facilitating teacher learning as an open system, (b) embracing dynamism across the systems by creating spaces for flexibility and nonlinearity, and (c) exerting the leadership mechanism at the meso level. Study suggests that complexity theory could better position SSDs with the lens and tools to address the complex issues that arise amidst the dynamics of decentralisation.