ontoref/assets/presentation/save_slides.md

---
theme: default
#theme: ./themes/rust-vibe
title: Why I Needed Rust
titleTemplate: '%s - Rustikon 2026'
layout: cover
keywords: Rust,programming
download: true
exportFilename: Rustikon_2026_Why_I_Need_Rust
monaco: true
remoteAssets: true
selectable: true
record: true
colorSchema: dark
#colorSchema: white
lineNumbers: false
themeConfig:
  primary: '#f74c00'
  logoHeader: '/ferris.svg'
fonts:
  mono: 'Victor Mono'
drawings:
  enabled: true
  persist: false
  presenterOnly: false
  syncAll: true
scripts:
  - setup/image-overlay.ts
background: ./images/charles-assuncao-1BbOtIqx21I-unsplash.jpg
class: 'justify-center flex flex-cols hoto-bg'
---

<h1 class="absolute top-11 left-1/4 font-medium"> Why I Needed Rust </h1>

<h2 class="absolute top-35 left-2/10 font-medium">
  Finally, Infrastructure Automation I Can Sleep On
</h2>

<img class="absolute top-48 left-4/10 w-45" src="/jesusperez_w.svg">

<div class="hidden meters-slide bg-transparent!">
  <span> 🛡 ●●●○○</span>
  <span> 😴 ●●●○○</span>
  <span> 🔥 ●○○○○</span>
</div>

<style scoped>
h1, h2, p { z-index: 10}
.meters {
  margin-top: 2rem !important;
  display: flex;
  gap: 2 rem;
  font-size: 1rem;
  opacity: 0.6 !important;
  font-family: monospace;
}

.two-cols {
    column-gap: 1.5rem !important;
}

</style>

<Footer />

<!--
Open: "Who here has been woken up at 3 AM by an infrastructure failure?"

Pause. Look at the room. Nod.

"This talk is for you."
-->

---

# <YearsCounter :startYear="1988" :speed="80" :delay="1" /> Years. One Problem.

**1987 → 2025**

<div class="journey">

| Era | Tool | Lesson |
|-----|------|--------|
| 1990s | Perl | Power without safety is a disaster |
| 2000s | Python | Pragmatism without guarantees is fragile |
| 2010s | Bash · Chef · Ansible · Terraform | More tools don't solve paradigm problems |
| 2020s | Go · ??? | |

</div>

<div class="box-highlight text-shadow-lg text-sm p-2 w-1/3 ml-1/3">
Each time, I thought I had the answer. <br>
Each time, reality proved me wrong. 
</div>

<!--
Don't dwell. Move fast through this slide.
The point is: I've tried everything. This isn't a beginner's opinion.
-->

---
layout: cover
background: ./mYBMP8pW4uQ.webp
class: 'text-center photo-bg'
---

# The Evolution

How we got here

---

# Stage 1 — Local (late 80s / early 90s)

**Dumb terminals. Single machine. One state.**

- Local development, long deployment cycles, low urgency
- One state — easy to observe, easy to control
- IaC: procedural scripts, logic hidden inside the application

<br>

> **The Perl Era:** we could do anything.
>
> We could also break anything.
>
> Beautiful, terrifying metaprogramming.
>
> No safety net.

> Silent failures at 3 AM.
>
> *Lesson: power without safety is a disaster.*

<div class="meters-slide">
  🛡 ●●●●○ &nbsp; 😴 ●●●●○ &nbsp; 🔥 ●○○○○
</div>

<!--
You had one server. You knew what was on it.
You could sleep.
-->

---

# Stage 2 — Networks / Internet

**Systems getting farther away. More people. More coordination.**

- Remote access, distributed teams, security becomes relevant
- Cost of downtime rises — processes become critical
- Harmonizing: package installs, config, updates across multiple machines in parallel
- IaC: reproducible automation, first declarative attempts

<br>

> **The Python Era:** rapid development, great community.
>
> But nothing stopped you from being wrong.
>
> Type hints came late — and optional.
>
> Runtime errors >> compile-time errors.
>
> *Lesson: pragmatism without guarantees is fragile.*

<small>More pieces. More people. Getting interesting.</small>

<div class="meters-slide">
  🛡 ●●●○○ &nbsp; 😴 ●●●○○ &nbsp; 🔥 ●●○○○
</div>

---

# Stage 3 — Containers / Cloud / CI-CD

**Everything. Everywhere. All at once.**

- Monolith → distributed, 24×7×365, high availability
- Cloud, hybrid, multi-cloud, on-prem — simultaneously
- Rollback and rollforward: database transactions, but for infrastructure
- Scale horizontally AND vertically — and *descale*
- CI/CD continuous: new features, new deploys, permanent churn

<br>

> **The Cloud/IaC Era:** Ansible, Terraform, Chef, Puppet.
>
> What changed? The syntax.
>
> What didn't? The fundamental problems.
>
> Still fighting type safety. Still discovering errors in production.
>
> *Lesson: more tools don't solve paradigm problems.*

<br>
<div class="meters-slide">
  🛡 ●●○○○ &nbsp; 😴 ●○○○○ &nbsp; 🔥 ●●●●○
</div>

<!--
Did we increase productivity? Yes.
Did we increase stress? Yes.
Did we increase the chances of failure? Also yes.
Do we have more control and safety? No.
-->

---
layout: cover
background: ./3XXSKa4jKaM.webp
---

<div class="standalone-slide photo-bg w-140 p-5 ml-1/5 box-highlight text-shadow-lg">

I could automate infrastructure.

But I couldn't make it reliable.

I couldn't prevent mistakes.

**I couldn't sleep.**

</div>

<div class="meters-standalone">
  🛡 ●○○○○ &nbsp;&nbsp; 😴 ○○○○○ &nbsp;&nbsp; 🔥 ●●●●●
</div>

<style>
.standalone-slide {
  font-size: 2rem;
  line-height: 2.2;
  text-align: center;
  color: var(--slidev-theme-foreground);
}
.standalone-slide strong {
  color: #e74c3c;
}
.meters-standalone {
  position: absolute;
  bottom: 3rem;
  left: 50%;
  transform: translateX(-50%);
  font-family: monospace;
  font-size: 1rem;
  opacity: 0.8;
  letter-spacing: 0.25em;
}
</style>

<!--
No irony here. Personal. Long pause after "I couldn't sleep."

What you can't measure: fear.
-->

---
layout: cover
class: text-center
---

    
# Why IaC Fails

The restaurant problem

<img class="inline" src="/failed.png" width="100">

    
---
layout: two-cols
class: 'restaurant bg-photo'
---
<style>
.slidev-layout.two-columns:has(.restaurant) {
  background-image: linear-gradient(rgba(0,0,0,0.62), rgba(0,0,0,0.62)),
    url("./images/blackieshoot-fuR0Iwu5dkk-unsplash.jpg") !important
  ;
  background-repeat: no-repeat;
  background-position: center center;
  background-size: cover !important; 
}
.restaurant {
  color: white !important;
}
</style>
# The Restaurant

Every restaurant has at least three actors.

| Restaurant | Infrastructure |
|---|---|
| Guest declares<br> what they want | Declarative config <br>(YAML, HCL) |
| Waiter validates<br> and transmits | Orchestrator<br> (K8s, Ansible) |
| Kitchen executes<br> and delivers | Runtime / provisioning |
| Dish arrives —<br> or doesn't | Deployment succeeds — or not |

::right::

**What makes it work — or not:**

The guest **declares**.  Doesn't implement.

The waiter must know what's possible — <br> *before going to the kitchen*.

> "I want X" → waiter goes to kitchen
><br> → "we don't have X, why is it on the menu?"
><br>→ back to the table.
><br>
><br>
> Equivalent: I configured a host with port 8443<br>→ that port isn't allowed<br> → reconfigure from zero.

<!--
The declarative model is correct. The problem is validation.

Key insight: the waiter is the orchestrator. They're the one who should catch impossible orders.
-->

---
layout: two-cols
---

# The Truth That Mutates

**State is not static.<br> It can change at every step of the chain.**

<div class="chain">

| Step | <span class="ulvibe">**Truth**</span> for this actor |
|---|---|
| Guest speaks | What they want |
| Waiter's notepad | What was written down |
| Kitchen markings | What's done / not done |
| Payment ticket | What was actually served |

</div>

> <span class="ulvibe">**Fail early = fail cheap. Fail in production = nightmare.**</span>

::right::

<div style="margin-top: -15px">

**The context problem:** <br>
The waiter knows the regular customer:<br> *"always no salt."* <br>

The kitchen doesn't. If the waiter changes<br> — that context disappears.

<span class="ulvibe">**Configuration drift is the same thing:**</span> Implicit state. Not explicit. Not propagated. Lost silently.

<span class="ulvibe">**The cost of failure depends on *where* it happens:**</span>
- Fail at the *table* (impossible order):<br> cheap — caught before kitchen
- Fail in *kitchen* (ingredient missing):<br> medium — renegotiate with guest
- Fail at *delivery* (wrong dish arrives):<br> expensive — experience destroyed

</div>

<!--
"No mushrooms available — can I substitute vegetables?"
That renegotiation must be explicit. Traced. Re-authorized. Not silent.
-->

---

# "We Don't Have Mushrooms"

**When an actor in the chain can't fulfill part of the order.**

> "Can I substitute vegetables?"
>
> That renegotiation must be **explicit. Traced. Re-authorized.**<br>Not silent. Not assumed.

<span class="ulvibe">**Configuration drift is silent renegotiation:**</span><br>
The system changes. Nobody notified. State diverges without trace.

**Rust's answer — `Option<T>`:**

```rust
// The waiter cannot silently skip a missing ingredient
let mushrooms: Option<Ingredient> = order.mushrooms;
match mushrooms {
    Some(m) => add_to_dish(m),
    None    => renegotiate_with_guest(&guest)?, // explicit. always.
}
// drift = treating None as Some. Rust makes that impossible.
```

> *The compiler is the waiter who cannot pretend an ingredient exists.*

<!--
Option<T> is the language-level answer to configuration drift.
The restaurant analogy closes here before we move to YAML hell.
-->

---

# The Config Evolution

**How we got from code to YAML hell**

<div class="evolution">

1. **Hardcoded** — everything inside the binary. Full control. Zero flexibility.

2. **External config (JSON)** — works between machines. Unreadable for humans at scale.

3. **YAML / TOML** — more readable. Fragile syntax. Implicit types. Silent errors.

4. **YAML + Serde** — Serde validates the *structure*:
   - Does the field exist? Is it the right type?
   - Do we accept `"elephant"` as a pet? If the type is `String`... yes.
   - **Serde validates shape. Not meaning.**

5. **Helm / Jinja templates** — YAML generated from variables (in YAML).
   - Does it validate the content of the generated YAML? **No. Not at all.**
   - Like using an LLM with a markdown reference: the format is there,
     but is the content correct?<br>Nobody guarantees that.

</div>

<style>
.evolution { font-size: 0.9rem; }
</style>

<!--
We got tired of writing YAML. So we wrote tools that write YAML.

The output of those tools? Still not semantically validated.

We just added a layer of indirection between us and the problem.
-->

---
layout: cover
background: ./3XXSKa4jKaM.webp
---

<div class="standalone-slide photo-bg w-90 p-5 ml-1/3 box-highlight text-shadow-lg title-slide bg-gray-800 opacity-85">

Continuous CI/CD.

No semantic validation.

**Continuous hope.**

<span style="font-size: 1.2rem; opacity: 0.6;">(crossing our fingers in production)</span>

</div>

<div class="meters-standalone ml-1/3">
  🛡 ●○○○○ &nbsp;&nbsp; 😴 ○○○○○ &nbsp;&nbsp; 🔥 ●●●●●
</div>

<!--
"What we do is write what we want — like a letter to Santa Claus. And we cross our fingers."

Ironic tone. The audience recognizes this.
-->

---
class: items-list
---

<style>
.items-list li {color: #676464;}
</style>

# Three Questions Without Answers

<div class="text-xl"> Question 1 — <span class="text-orange-500">
    — Why do we wait for things to break?
</span></div>

- "Works on my machine" — in production, I don't know
- Fail late = maximum cost. We want: fail fast, fail cheap

<div class="text-xl"> Question 2 — <span class="text-orange-500">
    — Do we actually know what we want?
</span></div>

- Is the declaration sufficient and consistent with what's *possible*?
- What are the boundaries? Static or dynamic? What is the source of truth — and when does it mutate?

<div class="text-xl"> Question 3 — <span class="text-orange-500">
    Can we guarantee determinism ?
</span></div>

- CI/CD without semantic validation = continuous hope
- We want certainty, not randomness
- "Works on my machine" cannot be the production standard

> *We're not inventing anything new. Everything already exists.
> The question is whether we're managing it correctly.*

<!--
These three questions are the core of the talk.
Everything that follows is Rust's answer to each one.
-->

---
layout: cover
background: /jr-korpa-vg0Mph2RmI4-unsplash.jpg
---

<div class="standalone-slide photo-bg w-90 p-5 ml-1/3 box-highlight text-shadow-lg title-slide bg-gray-800 opacity-75">

The *tools* weren't the problem.

The *languages* weren't the problem.

**The paradigm was the problem.**

</div>

<!--
Moment of clarity. Everything snaps into place.

I needed something that forced clarity — not enabled chaos.
That prevented errors — before production.
That made assumptions explicit — not hidden.
-->

---
layout: cover
background: andrew-neel-jtsW--Z6bFw-unsplash.jpg
---

<div class="standalone-slide photo-bg w-90 p-5 ml-1/3 box-highlight text-shadow-lg title-slide">

Systems we don't know how to control.

We hope they work.

When they don't — we fix them.

**Continuous nightmare.**

<span style="font-size: 1.2rem; opacity: 0.6;">(<span class="ulvibe"> alarm state</span> as the new normal)</span>

</div>

<div class="meters-standalone ml-1/3">
  🛡 ●○○○○ &nbsp;&nbsp; 😴 ○○○○○ &nbsp;&nbsp; 🔥 ●●●●●
</div>

<!--
No irony. Dark. This is the emotional floor of the talk.

Long pause here. Let it land.

Then: "There's a better way."
-->

---
layout: section
---

<img src="/ferris-heart.svg" width="120" class="-mt-5 ml-2.17/5">
  
<div class="text-8xl font-semibold mt-5"> Rust </div>

The answer to all three questions

<img src="/rust-laspalmas-dark.svg" width="280" class="-mt-8 ml-1.7/5">

---

# The Bridge: From Serde to Types

Serde loads structurally valid config.<br>
But `"elephant"` as `pet: String` compiles.

**Rust's answer: don't use `String`. Use a type.**

```rust
// Before: String — anything goes
pet: String  // "elephant" compiles. "unicorn" compiles. 🤷

// After: closed domain — impossible values don't exist
enum Pet { Dog, Cat, Rabbit }  // "elephant" doesn't compile
```

**This is the shift.**: 

<h4 class="box-highlight p-2">Not the config format. The model of what it can contain.</h4>

<u>Serde</u> validates <span class="ulvibe">shape</span> |  <u>Types</u> validate <span class="ulvibe">meaning</span><br>

The <u>compiler</u> validates *before the binary exists*.<br>

<!--
This is the answer to Question 2: "Do we know what we want?"

Yes. When we define it as a type.
-->

---

# What Rust Gives Us

<span class="text-gray-300">Answer to Question 1:</span> <span class="ulvibe font-semibold">fail early, fail cheap</span>

```rust
// Immutability by default — invariants are invariants
let config = load_config()?;  // cannot change silently
// Option<T> — no nulls, no assumptions
let mushrooms: Option<Ingredient> = order.mushrooms;
match mushrooms {
    Some(m) => add_to_dish(m),
    None    => notify_kitchen_to_skip(),  // explicit. always.
}
// Enums as closed domains
enum CloudProvider { Hetzner, UpCloud, AWS, GCP, Azure, OnPrem }
enum Port { Valid(u16) }  // not any integer — a valid port
```

<span class="text-gray-300">Answer to Question 2:</span> **explicit contracts**

```rust
// Traits define what every actor in the chain must fulfill
#[async_trait]
pub trait TaskStorage: Send + Sync {
    async fn create_task(&self, task: WorkflowTask) -> StorageResult<WorkflowTask>;
    async fn update_task(&self, id: &str, status: TaskStatus) -> StorageResult<()>;
    // Add a new provider: implement this trait or it doesn't compile
}
```

<!--
"I want tomato. You can invent whatever you want —
but without tomato, it's not the dish I ordered."

That's immutability. Invariants stay invariant.
-->

---
layout: two-cols
---

# The Compiler as Pre-Validator

<span class="text-gray-300">Answer to Question 3:</span> 
 <span class="ulvibe font-semibold">**guaranteed determinism**</span>

```rust
// Closed domain — you can't forget a case
enum RollbackStrategy {
  ConfigDriven,
  Conservative, // preserve unless marked deletion
  Aggressive,  // revert all changes
  Custom { operations: Vec<String> },
}
// The compiler enforces exhaustive handling
match strategy {
    RollbackStrategy::ConfigDriven  => ...,
    RollbackStrategy::Conservative  => ...,
    RollbackStrategy::Aggressive    => ...,
    RollbackStrategy::Custom { .. } => ...,
    // miss one → compile error
}
```

::right::

**The** *compiler* **validates:**
- Before building the binary
- Not after hours of execution
- Not when a function nobody touched in months finally gets called
- Predictable behavior: <br> memory, resources, workflows

<div class="box-highlight text-sm font-semibold">
 The compiler is the waiter who validates the order.<br>
 Before it reaches the kitchen.<br>
 Before the guest waits.<br>
 Before any ingredient is missing.<br>
</div>

<div class="meters-slide">
  🛡 ●●●●○ &nbsp; 😴 ●●●●○ &nbsp; 🔥 ●●○○○
</div>

---
layout: cover
background: clouds_lpa.jpg
---

<div class="standalone-slide -mt-8 photo-bg px-5 box-highlight text-shadow-lgi title-slide bg-gray-900 opacity-70">

# The Human Impact

**When the system is trustworthy:**

<div class="impact-grid">

✓ Sleep comes back

✓ Confidence returns

✓ The team trusts the automation

✓ Stress decreases

✓ You can actually rest

</div>

> *What you can't measure: <span class="text-white">fear</span>.*
>
> *What you can measure: <span class="text-white">MTTR</span>.*
>
> *Before: > 30 minutes. Now: <span class="text-white">< 5 minutes</span>.*

</div>

<style>
.impact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin: 2rem 0;
  font-size: 1.4rem;
}
</style>
<br>
<div class="meters-slide">
  🛡 ●●●●●&nbsp; 😴 ●●●●●&nbsp; 🔥 ●○○○○
</div>

---
layout: cover
background: /jude-infantini-mI-QcAP95Ok-unsplash.jpg
---

<div class="standalone-slide box-highlight ml-1.5/5 w-150 text-shadow-lg text-2xl">

Continuous CI/CD.

Types. Compiler. Explicit state.

<span class="font-extrabold">**Continuous certainty.**</span>

<span style="font-size: 1.2rem; opacity: 0.6;">(to keep sleeping well)</span>

</div>

<div class="meters-standalone ml-1.5/5">
  🛡 ●●●●● &nbsp;&nbsp; 😴 ●●●●● &nbsp;&nbsp; 🔥 ●○○○○
</div>

<!--
Resolution. The arc closes.

The title of the talk, demonstrated.
-->

---
layout: section
---

<img src="/ferris-heart.svg" width="120" class="-mt-4 ml-2.17/5">
  
<div class="text-7xl font-semibold mt-4"> In Production </div>

This is not theory

<img src="/provisioning.svg" width="280" class="ml-1.7/5">


---
layout: center
name: provisioning
---

<script setup>
import { ref, computed } from 'vue'
const useWhite = ref(false)
const bgStyle = computed(() => ({
  backgroundImage: `url('${useWhite.value ? "/w-arch-diag-v2.svg" : "/arch-diag-v2.svg"}')`,
  backgroundSize: 'contain',
  backgroundRepeat: 'no-repeat',
  backgroundPosition: 'center',
  position: 'absolute',
  inset: '0',
  cursor: 'pointer',
}))
</script>

<div @click="useWhite = !useWhite" :style="bgStyle" />

<div @click="useWhite = !useWhite" style="position: absolute; bottom: 1.2rem; right: 1.5rem; opacity: 0.35; font-size: 1.1rem; cursor: pointer; user-select: none;">
  🌗
</div>

<!--
Architecture overview. Let it breathe.
Don't narrate every component — just: "this is what we're talking about."
-->

---
layout: two-cols
---

# Nickel 

**YAML rejected. TOML rejected.<br>Reason: no type safety.**

YAML wrote what we wanted.<br> 
It couldn't say what was *possible*.<br>

Nickel closes that gap <br>
— at config time, not at 3 AM.

```haskell
# Infrastructure schema 
# — validated at config compile time
{
  compute | {
    region | String,
    count  | Number & (fun n => n > 0),
    scaling | {
      min | Number & (fun n => n > 0),
      max | Number & (fun n => n >= min), 
      # -- compiler verifies this relationship
    }
  }
}
```
::right::
# Typed Source of Truth
Result (ADR-003):<br>**zero configuration type errors in production.**

Config hierarchy:<br>

defaults → workspace → profile → <br> environment → runtime
<br>
<br>
Each layer merges.<br>
Type system catches conflicts.<br>
At config time — not deployment time.

The guest wrote an impossible order.<br>
Nickel makes impossible orders unwritable.

> *Serde validates shape.*
>
> *Nickel validates meaning.* 
>
> *The compiler validates before deployment.*

<!--
This is the practical answer to "how do you do typed IaC?"

Not YAML + validation script. Not JSON Schema. A typed language.
-->

---
layout: two-cols
---

# Traits as Provider

**The kitchen can change.<br>AWS ≠ UpCloud ≠ bare metal. Same menu.**

```rust
// Every provider implements the same contract
enum DependencyType { Hard, Soft, Optional }
enum TaskStatus     { 
      Pending, Running, Completed, Failed, Cancelled
}
// Dependency resolution 
// — the orchestrator knows the order
// Installing Kubernetes:
//   containerd (Hard) → etcd (Hard) → kubernetes
//   → cilium (requires kubernetes)
//   → rook-ceph (requires cilium)
```

**Explicit state — no drift:**

```rust
pub struct WorkflowExecutionState {
    pub task_states: HashMap<String, TaskExecutionState>,
    // what happened and when
    pub checkpoints: Vec<WorkflowCheckpoint>,
    pub provider_states: HashMap<String, ProviderState>,
}
```
::right::
#  Contracts
<br>
<br>

- Checkpoint every 5 minutes
- No implicit state. 
> No *"the waiter remembers the customer doesn't want salt."*
- It's in the order. Always. Explicit.

<!--
Add a new provider: implement the trait or it doesn't compile.
There's no way to forget a case.
-->

---
layout: two-cols
class: -mt-7
---

# Dependency Graph 

**Fail_fast: bool is not a config option.<br>
It's a principle encoded as a type.**

Typed DAG — dependency resolution enforced<br> at workflow compile time:

The kitchen doesn't serve the main course <br> before the starter is done.<br>

`DependencyType::Hard` is that rule.<br> In the type system, not in a runbook.

```rust
pub struct WorkflowConfig {
    pub max_parallel_tasks:          usize,
    pub task_timeout_seconds:        u64,
    // halt on first failure
    pub fail_fast:                   bool, 
    // recovery point granularity
    pub checkpoint_interval_seconds: u64,
}
containerd (Hard) → etcd (Hard) → kubernetes  
           → cilium    (requires: kubernetes)
           → rook-ceph (requires: kubernetes + cilium)
```

::right:: 

# Fail Fast, Fail Cheap
<br>
<br>

- `DependencyType::Hard` <br> - failure stops the chain. Always.
- `DependencyType::Soft` <br> - continues, explicitly degraded.
- `DependencyType::Optional` <br> - missing is expected and fine.
<br>
> *The compiler catches the install order.*<br>
> *Not the on-call engineer at 2 AM.*

<div class="meters-slide">
  🛡 ●●●●● &nbsp; 😴 ●●●●● &nbsp; 🔥 ●○○○○
</div>

<!--
The bridge between "fail early = fail cheap" and the actual production code.
-->

---
layout: two-cols
---

# Real Applications

### Kubernetes

The orchestrator provisions cluster<br>components as a typed workflow:

```
containerd
  → etcd
  → kubernetes control plane
    → CoreDNS
    → Cilium (CNI)
    → Rook-Ceph (storage)
```
Each dependency is a `DependencyType`.<br>
The compiler catches: <br>installing Cilium without Kubernetes.<br>
Not the on-call engineer at 2 AM.<br>

>*"In my machine it works" has a price here.*
>
> *This is the highest-stakes infrastructure in the deck.*

::right::

### Blockchain Validators

Validators require brutal uptime.<br>
A validator that fails loses funds — not your infrastructure's money.<br>
**Your customer's.**

- **Post-quantum cryptography**: CRYSTALS-Kyber + Falcon + AES-256-GCM hybrid. Validator keys protected against quantum computers.
- **SLOs with real error budgets**: 99.99% = 52.6 min downtime/year. Prometheus blocks deploys when burn rate exceeds budget.
- **Deterministic config**: validator parameters are types. A `bond_amount` that isn't a valid `u128` doesn't compile.

<!--
These are not toy examples.
Production systems with SLOs, encryption, and self-healing.
-->

---
layout: two-cols
---

# Disaster Recovery

**Rollback as a type, not a procedure**

3 AM. Something broke. You need to rollback.<br>
Without types: you improvise.<br>
With types: you choose a strategy<br>
— or it doesn't compile.

```rust
// Checkpoint = complete system snapshot
pub struct Checkpoint {
    pub workflow_state:  Option<WorkflowExecutionState>,
    pub resources:       Vec<ResourceSnapshot>,
    pub provider_states: HashMap<String, ProviderState>,
}
// Rollback strategy = typed choice, not a runbook
enum RollbackStrategy {
  ConfigDriven,
  Conservative, // preserve unless marked for deletion
  Aggressive,  // revert all changes
  Custom { operations: Vec<String> },
}
// You cannot do rollback without choosing a strategy.
// The compiler doesn't let you ignore the case.
```
::right::

<br>

**Multi-backend backup:** restic, borg, tar, rsync<br>
— all as enum variants.<br>

Production backup and DR restore use the same type, the same schema.

> *The runbook exists.*
>
> *Nobody reads it clearly at 3 AM under pressure.*
>
> *The type forces the decision before the crisis.*
>
> *The state is the same in prod and in DR. Always.*

<!--
Self-healing (ADR-010): RemediationEngine runs typed playbooks.
If remediation fails 3 times, it escalates to a human.
It doesn't loop indefinitely.
-->

---
layout: two-cols
---

# Self-Healing 

<br>

> **When something breaks at 3 AM** <br>
> — **the system responds, not you.**

<br>
```rust
enum RemediationAction {
  ScaleService    { service: String, replicas: u32 },
  FailoverService { service: String, region: Region },
  RestartService  { service: String },
  ClearCache      { service: String, scope: CacheScope },
}
// Typed playbooks. Not shell scripts. Not hope.
// Fails 3 times → escalates to human.
// Never loops indefinitely.
```

::right::

# — Typed Remediation

<br>

**What happens at 3 AM:**

- Alert fires <br>→ `RemediationEngine` matches condition<br> → runs `RestartService`<br>

- Works: silent. Nobody woken up.<br>
- Fails 3×: page sent <br>— with full state, checkpoint, and execution history.
<br>
<br>

> *You wake up to information. Not to chaos.*

<div class="meters-slide">
  🛡 ●●●●● &nbsp; 😴 ●●●●● &nbsp; 🔥 ●○○○○
</div>

<!--
ADR-010: automated incident response.
"At 3 AM, without you." — this is what that means, concretely.
-->

---
layout: cover
background: /jude-infantini-mI-QcAP95Ok-unsplash.jpg
class: photo-bg
---

<div class="standalone-slide box-highlight ml-0.8/5 w-200 text-shadow-lg text-2xl mttr">

Without types. Without compiler. Without explicit state.

**MTTR > 30 minutes.**

<div class="divider">────────────────────────</div>

Rust. Types. Explicit state.
Automated response.

**MTTR < 5 minutes.**

<span style="font-size: 1.2rem; opacity: 0.6;">(at 3 AM. without you.)</span>

</div>

<div class="meters-standalone ml-0.8/5 -mt-2">
  🛡 ●●●●● &nbsp;&nbsp; 😴 ●●●●● &nbsp;&nbsp; 🔥 ●○○○○
</div>

<style>
.mttr { line-height: 1.8; }
.mttr strong { color: #27ae60; }
.mttr strong:first-of-type { color: #e74c3c; }
.divider {
  margin: 1.5rem 0;
  opacity: 0.3;
  font-size: 1.2rem;
}
</style>

<!--
Real numbers. Not promises.

Pause after "without you."
That's the title of the talk.
-->

---
layout: two-cols
---

<div class="mt-0.8/2 text-2xl">

<h1 class="text-7xl font-semibold pb-5"> Why This Matters</h1>

For everyone in this room
</div>

::right:: 

<img src="/crate_in_wall.jpg" class="object-cover object-center rounded-lg h-120">


---
layout: two-cols
---

# For You

<h3 class="ulvibe">If you've been frustrated like me</h3>

- Rust solves the problems *you already know*<br>
  — not hypothetical ones
- This isn't hype. I've seen technologies<br>
  come and go for decades.
- Give it a real chance.
- Your sleep will thank you.

<h3 class="ulvibe font-semibold">Start here:</h3>

- Model your infrastructure as types
- Replace stringly-typed config with enums
- Let the compiler be your pre-validator

::right::

<br>
<br>
    
<h3 class="ulvibe">If you're earlier in your career</h3>

- Don't waste decades on fragile infrastructure
- Start with type safety from day one
- Build for reliability — not just for speed
- You'll thank yourself later

<br>
<br>
    
<h3 class="mt-2 ulvibe font-semibold">The shortest path:</h3>

- Learn the type system deeply
- Understand ownership as state management
- Traits as contracts between systems

<!--
Not a sales pitch. Not evangelism.
38 years of experience saying: this matters.
-->

---
layout: cover
background: ./mYBMP8pW4uQ.webp
class: 'text-center photo-bg'
---

<div class="standalone-slide text-shadow-lg text-3xl perspective">

At my age, I have perspective.

I've seen technologies come and go.

*Rust isn't hype. It's the right place.*

It solves real problems
I've had for decades.

More years isn't a liability.

**It's an advantage.**

</div>

<style>
.perspective { line-height: 2; }
.perspective strong { color: #e67e22; }
</style>

<!--
Not an apology. Not bragging.

Just: I can tell you — from experience — this matters.
-->

---
layout: cover
name: end
background: ./images/cleo-heck-1-l3ds6xcVI-unsplash.jpg
class: 'photo-more-bg'
---

<div class="standalone-slide text-shadow-lg text-xl perspective">

# Why I Needed Rust

## Because I Wanted to Sleep

<div class="meters-final mt-2 mb-6">
  <span>🛡 ●●●●●</span>
  <span>😴 ●●●●●</span>
  <span>🔥 ●○○○○</span>
</div>

<div class="text-5xl text-bold"> Thank you very much </div>

<br>
    
## Questions?

<small>More info: </small>

   · **jesusperez.pro** <br>
   
  <small> · **provisioning.systems** · **vapora.dev** · **rustelo.dev**  </small>
  
</div>

<style>
.meters-final {
  display: inline-flex;
  gap: 2rem;
  font-size: 1.4rem;
  font-family: monospace;
}
</style>

<!--
Final slide. Three meters in green.

The title of the talk, demonstrated.

Direct eye contact. Slow delivery.
-->