The centre-back endured an inconsistent debut season in England but has progressed this term, helping the Gunners bounce back from a miserable start to the campaign.
“I think for a defender it is the best championship. I have had a bit of time now to be strong and get to know this league,” the Frenchman told the club’s official website.
“Now I feel good on and off the pitch and I try to put the effort into being a good defender.
“You don't have to play differently here, you just have to work on the physical side. It's very different to France or Spain and the strikers are very strong. I've worked a lot to do that.”
Koscielny has shown his versatility in recent weeks after being shifted to right-back following injuries to Bacary Sagna and Carl Jenkinson, but admits he is not a natural in his new found position.
The 26-year-old added: “I try to do the defensive work. It is a little difficult to help Theo [Walcott] though because he is too quick! I try to give the best I can, and that's it. I can get forward once or twice a game.
"I try to do the job seriously but I hope Bacary or Carl come back quickly.”