> For the complete documentation index, see [llms.txt](https://docs.engma.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.engma.io/ravid/tech-stack.md).

# Tech Stack

| Layer              | Architecture Says     | We Implement With |
| ------------------ | --------------------- | ----------------- |
| **Infrastructure** | Cloud substrate + IaC | Azure + Terraform |
| **Network**        | Zero-trust overlay    | OpenZiti          |
| **Compute**        | BFT consensus         | (Vendor-agnostic) |
| **Storage**        | Shamir secret sharing | Keystore Service  |
| **Settlement**     | Public blockchain     | Ethereum          |

```
Technical: Implementation Stack Details

LAYER 0: INFRASTRUCTURE (Azure + Terraform)
├── Virtualization: Azure VMs, containers
├── Network isolation: VNets, NSGs
├── HSM: Azure Key Vault (FIPS 140-2 Level 3)
├── IaC: Terraform DAG for declarative state
└── Identity: Azure AD, managed identities

LAYER 1: STEALTH NETWORK (OpenZiti)
├── Identity: X.509 certificates, mTLS
├── Dark services: No listening ports on underlay
├── Mesh routing: Dijkstra over fabric routers
├── Encryption: ChaCha20-Poly1305 AEAD
└── Key exchange: X25519 ECDH

LAYER 2: BFT COMPUTE (Vendor-agnostic)
├── Consensus: Byzantine fault tolerant (80% threshold)
├── State: Replicated State Machine (RSM)
├── Leader: RAFT-style election
├── Execution: Deterministic contract logic
└── UNL: Unique Node Lists for trust

LAYER 3: KEYSTORE (Shamir + HD)
├── Split custody: 2-of-3 Shamir shares
├── Derivation: BIP-32 HD paths
├── Signatures: Ed25519 (internal), secp256k1 (EVM)
├── Threshold: Sign without reconstructing key
└── Recovery: Social recovery with timelock

EXTERNAL: ETHEREUM (ERC-20 + Contracts)
├── Token: ENX (ERC-20)
├── Staking: Lock ENX for node roles
├── Settlement: Proof verification
├── Slashing: Penalty for misbehavior
└── Entropy: Blockhash for DETSA

```