A system comprising: a diffuser section configured to receive an exhaust gas from a turbine section, wherein the diffuser section comprises an outer barrel, an inner barrel, a seal interface, disposed at a downstream end of the inner barrel, an aft plate, a forward plate, and a plurality of poles; wherein an upstream end of the outer barrel comprises an upstream lip configured to interface radially with a downstream lip of an outer wall of the turbine outlet, wherein the upstream lip and the downstream lip are configured to form a circumferential lap joint disposed about a turbine axis; wherein the outer barrel comprises a first plurality of axial segments disposed between the upstream end of the outer barrel and the forward plate, wherein the first plurality of axial segments comprises a first continuous curve away from the turbine axis from the upstream end of the outer barrel to the forward plate; wherein the inner barrel comprises a second plurality of axial segments disposed between an upstream end of the inner barrel and the seal interface, wherein the second plurality of axial segments comprises a second continuous curve away from the turbine axis from the upstream end of the inner barrel to the seal interface; characterized in that, the seal interface comprises a first circumferential groove configured to receive the aft plate, wherein the first circumferential groove opens in a first direction away from the turbine axis; and wherein the plurality of poles is circumferentially spaced about the turbine axis, and each pole of the plurality of poles couples a downstream end of the aft plate to a downstream end of the forward plate. a diffuser section configured to receive an exhaust gas from a turbine section, wherein the diffuser section comprises an outer barrel, an inner barrel, a seal interface, disposed at a downstream end of the inner barrel, an aft plate, a forward plate, and a plurality of poles; wherein an upstream end of the outer barrel comprises an upstream lip configured to interface radially with a downstream lip of an outer wall of the turbine outlet, wherein the upstream lip and the downstream lip are configured to form a circumferential lap joint disposed about a turbine axis; wherein the outer barrel comprises a first plurality of axial segments disposed between the upstream end of the outer barrel and the forward plate, wherein the first plurality of axial segments comprises a first continuous curve away from the turbine axis from the upstream end of the outer barrel to the forward plate; wherein the inner barrel comprises a second plurality of axial segments disposed between an upstream end of the inner barrel and the seal interface, wherein the second plurality of axial segments comprises a second continuous curve away from the turbine axis from the upstream end of the inner barrel to the seal interface; characterized in that, the seal interface comprises a first circumferential groove configured to receive the aft plate, wherein the first circumferential groove opens in a first direction away from the turbine axis; and wherein the plurality of poles is circumferentially spaced about the turbine axis, and each pole of the plurality of poles couples a downstream end of the aft plate to a downstream end of the forward plate.