Hello Fakorede Abiola , Thanks you for your response. After reading it and the code again and again, I understand that I've missed a point: app.route take as many middleware as we want. Your cache middleware is scoped here and not global to all the app: app.get( '/repos/:username' , cache, async (req, res) => { So everythings is good. Thanks again for your article, this is a great discovery for me :)