Wilson’s renormalization group ideas form a cornerstone of modern quantum physics. They lead to a field theory understanding of critical phenomena. However, the enhanced symmetries at the critical point, namely conformal symmetries are not used as a result of which the calculations, which typically depend on evaluating and regularizing Feynman diagrams, are tedious and complicated. In 1974, Polyakov had put forward an idea based on the consistency between the operator product expansion (OPE) and crossing symmetry, which lay dormant for many years. I will revisit this idea and show how a reformulation in Mellin space leads to enormous calculational advantages—this leads to conformal bootstrap in Mellin space. The building blocks, in their modern incarnation, are what are called Witten diagrams in the AdS/CFT parlance. The calculational steps are manifestly finite. Several standard results are easily reproduced and several new results for the OPE coefficients, which are difficult to obtain in the diagrammatic approach, are obtained.