Algebraic soft-decision decoding of Reed-Solomon (RS) codes delivers promising coding gains over conventional hard-decision decoding. The most computationally demanding step in the soft-decision decoding is bivariate polynomial interpolation. In this paper, we present a very efficient high speed interpolation architecture based on hybrid data representation. It is shown that the proposed architecture is inherently scalable and can be extensively pipelined to achieve very high clock speed. By further incorporating the maximum overlapping for computations at adjacent iterations, the proposed architecture demonstrates significant advantages over conventional designs. It is estimated that over 1 Gbps data rate can be achieved using the presented work with moderate complexity.