The day his code hit production, the graphs went flat. A month later, HR called us in.

Before the Rewrite, We Were Drowning

We were a team of six. Backend engineers juggling microservices, pipelines, devops patches, and postmortems that read like therapy notes.

Our stack was typical for a fast-moving startup:

  • Node.js microservices
  • Redis queues
  • AWS Lambdas
  • MongoDB for almost everything

We weren't bad. We just weren't fast. Services were functional, but brittle.

Some mornings, we'd all be staring at Datadog dashboards watching a queue backlog climb past 10k messages, waiting for garbage collection to catch up.

We were firefighting. Every day.

Then Kabir, the quietest one of us, said,

"I think I can rewrite this image pipeline in Rust."

What Happened Next Should've Been Obvious

We all shrugged. Rewrites never survive.

But Kabir didn't ask for help. He didn't book design meetings or ask for estimations. He just started doing it.

Quietly.

While we were patching broken pagination in our API, he was benchmarking image-rs against our Node scripts.

We didn't even notice — until he demoed it.

The Numbers That Made Us Obsolete

Kabir demoed the new Rust service in our next sprint review. We smiled. We clapped.

We didn't understand we were applauding our own replacement.

Here's what he showed:

| Metric               | Node.js (Before) | Rust (After) |
| -------------------- | ---------------- | ------------ |
| P95 Latency          | 243ms            | **39ms**     |
| Lambda Cold Start    | 1.8s             | **240ms**    |
| Memory Usage         | 300MB            | **32MB**     |
| Daily Errors         |  ~500            | **<10**      |
| Infra Cost (monthly) |  ~\$1200         | **$110**     |

Kabir didn't just improve performance. He reduced AWS bills. He eliminated flaky dependencies. He made the on-call rotation almost boring.

We didn't say it then, but we all felt it: This wasn't just a better service. It was a better engineer.

The Rest of Us Fell Behind — Fast

Kabir became the performance guy.

While we were fixing broken Mongoose schemas and arguing over GraphQL vs REST, he was writing RFCs about zero-cost abstractions and epoll vs kqueue.

He wasn't arrogant. But he wasn't waiting for us either.

We started asking questions like:

  • "Why does this handler panic on a null payload?"
  • "What's a Pin<Box<T>> again?"
  • "Do I need to install nightly to run this?"

The gap widened fast.

One week, he was building our health check in Axum. The next, he had a production-ready rate limiter using atomic counters and parking_lot.

We stopped reviewing his PRs. We couldn't keep up.

The Org Shifted — Silently, Then Loudly

Kabir wasn't just building faster services. He was changing who owned what.

  • PMs started routing feature requests to him.
  • SREs asked him to help with Terraform changes.
  • Leadership started showcasing his dashboards in all-hands.

He became "the backend guy" — even though five of us still worked there.

We didn't lose our jobs that day.

But we stopped being the team.

Then the Layoffs Came

They didn't call it layoffs. They never do.

They said the company was "refocusing." That they were "optimizing delivery layers."

One by one, we got calendar invites from HR.

No PIPs. No warnings. Just "thank you for your time."

They kept Kabir.

Of course they did.

He was running half the infra now. And doing it better than we ever did as a team.

The Rewrite Wasn't Evil — It Was Logical

To be clear: Kabir didn't sabotage us. He didn't lobby against anyone. He didn't ask for the org to shrink.

He just made himself too valuable to cut.

And in a startup that measures ROI on every deploy, you don't cut the one person shipping 10x faster and 5x cheaper.

We weren't let go because we were bad. We were let go because he made us look optional.

Here's a Sample of The Kind of Code That Replaced Us

use axum::{Router, routing::get, Json};
use serde::Serialize;
#[derive(Serialize)]
struct Health {
    status: &'static str,
    uptime_seconds: u64,
}
async fn health_check() -> Json<Health> {
    Json(Health {
        status: "ok",
        uptime_seconds: std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_secs(),
    })
}
fn main() {
    let app = Router::new().route("/health", get(health_check));
    axum::Server::bind(&"0.0.0.0:3000".parse().unwrap())
        .serve(app.into_make_service())
        .await
        .unwrap();
}

Yes, it's clean. Yes, it's fast.

But it's not something a Node.js engineer can casually jump into.

The learning curve was vertical, and nobody else at the company climbed it.

Our Postmortem

Looking back, here's what went wrong — and none of it is about Rust.

1. We Ignored the Rewrite

We treated Kabir's rewrite like a pet project. We didn't pair with him. We didn't read the early commits. By the time we realized it was core infra, it was already live.

2. We Assumed Team > Talent

We thought culture, collaboration, and process mattered most. But when budgets got tight, the company didn't ask who's nice to work with. They asked who can ship without blockers.

3. We Didn't Learn the Tooling

We had a window to learn Rust — or at least understand it enough to help. But we stayed in our comfort zone. That cost us more than we thought.

Final Thought

Rust didn't fire us.

But a Rust rewrite without team buy-in can change who the team even is.

If one person is refactoring everything while the rest are writing Jira tickets, they're not just improving throughput — they're rewriting the org chart.

And if you're watching it happen?

Don't just watch.

Learn. Pair. Contribute. Or risk becoming history.