I'm building a developer-facing platform and need flexible routing and cache controls

A good way to think about this is: routing decides where a request goes; cache controls decide how reusable the response is. For a developer-facing platform, you’ll usually want both to be explicit, composable, and easy to override per route.

Flexible routing design

Consider supporting these routing primitives:

• Path-based routing
  • /api/users/:id
  • /v1/*
• Host-based routing
  • api.example.com vs docs.example.com
• Method-based routing
  • GET, POST, PUT, DELETE
• Header / query based routing
  • versioning via Accept: application/vnd...
  • feature flags via headers
• Weighted / canary routing
  • 90% to stable, 10% to new backend
• Fallback routing
  • primary backend, then secondary on failure

A clean route definition often includes:

• match rules
• upstream target(s)
• priority/order
• timeout/retry policy
• auth requirements
• cache policy
• observability tags

Example shape:

{
  "name": "get-user",
  "match": {
    "method": "GET",
    "path": "/v1/users/:id",
    "host": "api.example.com"
  },
  "upstream": {
    "type": "service",
    "name": "user-service"
  },
  "policy": {
    "timeoutMs": 1000,
    "retries": 2
  }
}

Cache control design

For cache controls, give developers explicit knobs at multiple layers:

1. Response caching

Support standard HTTP cache headers:

• Cache-Control: public, max-age=60
• Cache-Control: private, no-store
• ETag
• Last-Modified
• Vary: Accept, Authorization

2. Platform-level cache policy

Let routes define cache behavior independently of origin headers:

• enabled
• ttlSeconds
• staleWhileRevalidate
• staleIfError
• varyKeys
• cacheKeyTemplate
• bypassConditions

Example:

{
  "cache": {
    "enabled": true,
    "ttlSeconds": 30,
    "staleWhileRevalidateSeconds": 120,
    "vary": ["Accept", "X-Tenant-Id"],
    "bypassIf": [
      { "header": "Authorization", "present": true }
    ]
  }
}

3. Cache key customization

This matters a lot in multi-tenant or API-heavy platforms.

Cache key should usually include:

• method
• host
• path
• query string subset
• selected headers
• auth/tenant context
• locale, if relevant

Example key:

GET|api.example.com|/v1/users/123|tenant=acme|accept=application/json

Recommended features for developer UX

To make this truly developer-friendly:

• Defaults with overrides
  • global defaults, service defaults, route overrides
• Dry-run / preview mode
  • show which route matched and whether response would cache
• Config validation
  • reject conflicting route rules or invalid cache settings
• Metrics
  • hit rate, miss rate, stale serves, route match counts
• Debug headers
  • X-Route-Matched, X-Cache-Status, X-Upstream
• Versioned config
  • safe rollbacks and staged releases

Practical rule of thumb

Use this precedence order:

1. explicit route override
2. service-level default
3. platform default
4. HTTP origin headers, if allowed

That keeps behavior predictable.

If you want an opinionated starting point

A strong minimum viable model is:

• Routes: match, upstream, priority
• Cache: enabled, ttl, vary, bypass, staleWhileRevalidate
• Observability: route and cache debug headers
• Governance: config validation and versioned rollout

If you want, I can also draft:

1. a JSON schema for routing + cache policy,
2. an API design for managing rules,
3. or an architecture diagram for how the request flow should work.