HFT firms use all sorts of technologies. But to be clear, you want to be closest to trading - that's where the big money is; so either a) idea generation (quant

HFT firms use all sorts of technologies. But to be clear, you want to be closest to trading - that's where the big money is; so either a) idea generation (quant work) or b) execution (dev work) For the execution piece, C++ would be the most viable option. On the quant/research piece, python/R/kdb are common tools used, but the real skills are the statistics/math and market knowledge.