> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kvant.sbs/jeston/llms.txt
> Use this file to discover all available pages before exploring further.

# Production operations

# Production operations

***

## Operations · Production

> **Operational objective** — Operate Jeston as a workload with capacity, dependencies, incidents, and recovery—not as a static deployment.

A production posture for scaling, alerting, security, cost, and incident response.

### Key concepts

<Columns cols={3}>
  <Card title="Saturation" icon="sparkles">
    Queue, pool, CPU, memory
  </Card>

  <Card title="Tail latency" icon="shield-check">
    p95 and p99
  </Card>

  <Card title="Recovery" icon="gauge-high">
    Time to restore
  </Card>
</Columns>

### Runbook view

```mermaid placement="top-right" theme={null}
flowchart LR
    traffic[Traffic] --> app[Application workers]
    app --> db[(Database)]
    app --> queue[Queue]
    app --> providers[External providers]
    app --> telemetry[Telemetry and alerts]
```

### Evidence over assumption

| Signal       | Healthy interpretation   | Action when it degrades         |
| ------------ | ------------------------ | ------------------------------- |
| Saturation   | Queue, pool, CPU, memory | Predicts user-visible failure.  |
| Tail latency | p95 and p99              | Shows the slow users.           |
| Recovery     | Time to restore          | Measures operational readiness. |

<Warning>
  Optimize the bottleneck measured in the complete topology; do not optimize framework throughput in isolation.
</Warning>

### Operational context

Heavy systems fail at boundaries: queues fill, pools saturate, providers slow down, and tail latency grows before averages move.

> **Operator's principle**
>
> Production maturity is the ability to recover predictably, not the absence of incidents.

### Implementation notes

| Engineering move              | Guidance                                                                    |
| ----------------------------- | --------------------------------------------------------------------------- |
| **Set the capacity model**    | Estimate concurrency, pool size, memory, stream count, and provider quotas. |
| **Define service objectives** | Choose latency, error, freshness, and availability signals that matter.     |
| **Write runbooks**            | Give each alert an owner, diagnosis path, mitigation, and escalation.       |
| **Exercise failure**          | Practice dependency loss, overload, deploy rollback, and shutdown.          |

### Decision lens

| Mode             | Practical emphasis                                        |
| ---------------- | --------------------------------------------------------- |
| **Normal day**   | Dashboards, releases, capacity, and cost review.          |
| **Degraded day** | Rate limits, fallback, queue draining, and communication. |
| **Incident**     | Contain, diagnose, recover, and record learning.          |

## Related topics

<Columns cols={3}>
  * [gauge-high · **Measure load**](/jeston/jeston/operations/benchmark) — Read the focused guide for this boundary.
  * [chart-line · **Build telemetry**](/jeston/jeston/platform/health-observability) — Read the focused guide for this boundary.
  * [power-off · **Drain safely**](/jeston/jeston/operations/jobs-and-shutdown) — Read the focused guide for this boundary.
</Columns>

## References

[1]: https://github.com/jeffersoncampos12p-dev/jeston "Jeston source repository"

[2]: https://www.npmjs.com/package/@kvantjs/jeston "Jeston package on npm"

[3]: https://nodejs.org/api/http.html "Node.js HTTP API"

[4]: https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal "AbortSignal Web API"

[5]: https://react.dev/reference/react-dom/server "React server rendering APIs"

[6]: https://www.typescriptlang.org/docs/handbook/intro.html "TypeScript handbook"