Our Go-to-Rust Rewrite Cut Latency 3ms and Development Speed 70%

Ark Protocol

4 min read

·

Oct 5, 2026

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We shaved 3 milliseconds off p99 and lost eight merged pull requests a week.

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We spent eleven months rewriting a service that was already fast enough.

I was you. Some days, I still am.

The Service Nobody Complained About

Nothing exotic.

The p99 sat around 14ms. Customers were happy. On-call was boring, which is the highest compliment a service can get.

But I kept seeing allocation spikes in our traces. I convinced myself, and then my manager, that Rust would make that wobble disappear.

The Meeting Where I Sold It

My manager, Arjun, listened to the whole pitch without interrupting. When I finished, he asked one question. “What do we lose?”

Neither had anyone else in that room.

The Code Looked Beautiful

Here is roughly what the Go handler looked like:

func price(w http.ResponseWriter, r *http.Request) {
    id := r.URL.Query().Get("id")
    p, err := store.Get(id)
    if err != nil {
        http.Error(w, "not found", 404)
        return
    }
    json.NewEncoder(w).Encode(p)
}