Compose Hybrid Spec
Pick features from multiple specs and mix them into a single build. Notifications from Slack + payments from e-commerce? Go.
Source specs
Fan-out Architecture*
Ordering & Ranking*
Feed Capabilities
Tradeoffs
Read speed gains paid for by write amplification — cost scales with follower counts
Model training, feedback collection, and trust-and-safety review all expand
Requires a pub/sub layer (overlaps with notifications infra)
Threading Model*
Content Features
Moderation Controls
Tradeoffs
Mobile UX suffers past 3 levels; pagination and collapse behavior need design attention
Expand notification infrastructure — mention notifications are high-priority and user-visible
Third-party ML dependency and ongoing tuning of thresholds to balance false positive rate
Storage Backend*
File Processing
Tradeoffs
Not horizontally scalable; lost on server replacement without backup
Higher monthly cost; requires cache invalidation strategy
Upload latency increases; requires AV service integration
Conversation Types*
Message History*
Rich Content
Tradeoffs
Message routing logic grows significantly; fan-out to members must be handled carefully
Storage costs grow unbounded; requires indexing strategy for search
Requires object storage (S3/R2) and content moderation policy
Server must fetch external URLs on behalf of users; adds latency and SSRF risk
Delivery Method*
User Control
Tradeoffs
Requires persistent connection infrastructure (e.g. Redis pub/sub, WebSocket server)
Higher server request volume; notifications may lag by poll interval
Requires APNs/FCM credentials and certificate management
Significantly more complex preference storage and UI
Onboarding Format*
Personalization Signals
Activation Support
Tradeoffs
Controls first-experience but introduces sign-up drop-off proportional to wizard length
Requires event tracking + scheduled jobs + segmentation infrastructure
Staffing cost scales with signup volume — not viable for self-serve products below a certain ACV
Authorization Model*
Permission Scope*
Custom Role Management
Tradeoffs
Fast to build but every 'special case' access rule becomes bespoke code that's hard to audit
Requires a policy engine and relationship store kept in sync with primary data
Every list/read query must filter by ACL — expect query-plan work and caching investment
Support load increases substantially — each customer now has a unique permission configuration
Search Approach*
Search Scope*
Tradeoffs
Requires FTS index maintenance; adds write-time overhead
Embedding generation adds latency and API cost per indexed document
Results must be unified and ranked across disparate data models
Authentication Methods*
Access Control*
Multi-factor Authentication
Tradeoffs
Each provider requires an OAuth app registration and key rotation policy
Requires IdP partnership and XML-based protocol handling; significant integration work
Permission checks must be applied consistently across every data access path
Summary
9 of 9 composed features enabled
Pulled from 1 source spec
Effort Estimate
10+ weeks