I Ran DeepSeek V3.1 and V4 on Real Client Work — Here's the Bill (opens in new tab)

I Ran DeepSeek V3.1 and V4 on Real Client Work — Here's the Bill Last Tuesday I did something kind of dumb. I built the same feature twice — once with DeepSeek V3.1, once with the new V4 — for a client chatbot project. Two implementations, side by side, burning through my afternoon. But honestly? That single afternoon of "wasted" billable time probably saved me a couple grand over the next quarter. Let me explain. If you're a solo dev or running a tiny shop like me, every API call is a tiny l...