> ## 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.

# Deployment

# Deployment

***

## Operations · Deployment

> **Operational objective** — Move the same verified artifact through environments with explicit configuration and reversible topology.

A deployment sequence with probes, process ownership, secret injection, and rollback.

### Key concepts

<Columns cols={3}>
  <Card title="Artifact" icon="sparkles">
    Immutable
  </Card>

  <Card title="Probe" icon="shield-check">
    Actionable
  </Card>

  <Card title="Rollback" icon="gauge-high">
    Available
  </Card>
</Columns>

### Operational surface

```mermaid placement="top-right" theme={null}
flowchart LR
    commit[Commit] --> ci[CI verification]
    ci --> artifact[Build artifact]
    artifact --> deploy[Deploy] --> probe[Readiness probe]
    probe --> traffic[Traffic]
```

### Evidence over assumption

| Signal   | Healthy interpretation | Action when it degrades         |
| -------- | ---------------------- | ------------------------------- |
| Artifact | Immutable              | Same bits across environments.  |
| Probe    | Actionable             | Traffic only when safe.         |
| Rollback | Available              | Recovery without improvisation. |

### Operational context

Deployment is a controlled change to runtime behavior, not simply a command that starts Node.

> **Operator's principle**
>
> A deployment is successful when the operator can explain both how it starts and how it stops.

### Implementation notes

| Engineering move         | Guidance                                                                     |
| ------------------------ | ---------------------------------------------------------------------------- |
| **Build once**           | Create an artifact that does not change between verification and deployment. |
| **Inject configuration** | Use the environment or secret manager at runtime, not source control.        |
| **Probe before traffic** | Check liveness, readiness, and critical dependency behavior.                 |
| **Release gradually**    | Keep rollback, drain, and previous artifact access available.                |

### Decision lens

| Mode                 | Practical emphasis                                             |
| -------------------- | -------------------------------------------------------------- |
| **Single process**   | Simple topology with clear limits and restart behavior.        |
| **Multiple workers** | Coordinate ports, signals, shared state, and connection pools. |
| **Distributed**      | Add network, queue, storage, and deployment health contracts.  |

## Related topics

<Columns cols={3}>
  * [server-stack · **Run the service**](/jeston/jeston/operations/production) — Read the focused guide for this boundary.
  * [arrows-rotate · **Change schemas**](/jeston/jeston/operations/migrations) — Read the focused guide for this boundary.
  * [circle-check · **Verify artifacts**](/jeston/jeston/operations/release-checks) — 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"