It's been a year since I saw you. What have you been up to?
「一年ぶり」は英語で「It's been a year since」になります。
何をしていたのか尋ねるときは「What have you been up to?」と聞きます。
したがって、「It's been a year since I saw you. What have you been up to?」を提案しました。
It has been about a year since we saw each other. What have you been up to?
It has been about a year since we met. What have you been doing?
It has been about a year since I saw you. How have you been?
様々な表現があると思いますが、このような言い方ができると思います。
It has been about a year since we saw each other. What have you been up to?
約1年ぶりにお会いしましたね。この間何をしていましたか?
It has been about a year since we met. What have you been doing?
約1年ぶりにお会いしましたね。この間何をしていましたか?
It has been about a year since I saw you. How have you been?
約1年ぶりにお会いしましたね。元気でしたか?
ご参考になさってみてください。