I'm not sure about biggest, but on of the biggest sure. Two problems. 1. DNA sequencing, now is two part process (I simplify a lot, sure) - at first stage, target DNA divided for small pieces, and those pieces sequenced to digital codes and saved to database. Than in second part, computer cluster works few months, to connect those pieces to one chain. And this is very expensive process even considering few gigabytes…
2) see AlphaFold2 and other related methods -- the protein folding problem is still a big challenge but the field is moving in leaps and bounds