What is Ordo?

Ordo (Latin for "order") is an open-source decision platform for teams who need to own their decision logic — not scatter it across codebases, spreadsheets, and tribal knowledge.

It has three layers:

• Engine — sub-microsecond rule execution, JIT-compiled via Cranelift, runs everywhere (HTTP · gRPC · WASM · CLI).
• Platform — org and project management, fact catalog, decision contracts, version history, rule templates.
• Studio — visual flow editor, test case management, one-click template instantiation.

Why a Decision Platform?

Most teams start with a rule engine. Then they realize the hard part isn't execution speed — it's knowing what rules exist, who changed them, whether they still work, and how to hand them off to a new engineer.

Ordo addresses the full lifecycle:

Stage	What Ordo provides
Author	Studio flow editor, decision tables, template library
Test	Per-ruleset test cases, run in CI, export to YAML
Govern	Fact catalog, typed contracts, version history, audit log
Execute	Fast engine, hot reload, multi-tenancy
Observe	Execution traces, Prometheus metrics, structured logs

Architecture

┌─────────────────────────────────────────────────────────────┐
│                    Platform (ordo-platform)                  │
│  Org · Project · Fact Catalog · Contracts · Templates · Tests│
└──────────────────────────┬──────────────────────────────────┘
                           │
┌──────────────────────────▼──────────────────────────────────┐
│                      Studio (apps/studio)                    │
│         Flow Editor · Test Runner · Template Library         │
└──────────────────────────┬──────────────────────────────────┘
                           │
┌──────────────────────────▼──────────────────────────────────┐
│                     Engine (ordo-server)                     │
│   HTTP REST · gRPC · Unix Socket · Prometheus metrics        │
└──────────────────────────┬──────────────────────────────────┘
                           │
┌──────────────────────────▼──────────────────────────────────┐
│                      ordo-core (Rust)                        │
│   Interpreter · Bytecode VM · Cranelift JIT · WASM           │
└─────────────────────────────────────────────────────────────┘

Use Cases

Ordo is a good fit whenever business logic needs to be visible, testable, and changeable without a full deploy:

• Risk & compliance — credit scoring, fraud detection, KYC, regulatory policy
• Pricing & promotions — dynamic pricing, discount rules, campaign eligibility
• Routing & assignment — order routing, payment channel selection, load decisions
• Access & eligibility — loan approval, feature flags, subscription tier logic