StemBlock AI: Product-Led Growth Transformation Plan

Executive Summary

Transform StemBlock AI from a flat-access educational platform into a Product-Led Growth SaaS with freemium model, persona-specific workspaces, and strategic AI workflow expansion.

Key Objectives:

Implement 3-tier pricing (Community/Team/Enterprise) with clear value differentiation
Add workspace collaboration features for all personas (Student, Coach, Parent, Admin)
Gate AI features with usage limits and tier-based access
Build 4 new AI workflow systems to drive upgrade intent
Enable self-serve signup and upgrades via Stripe integration

Timeline: 14 weeks across 5 implementation phases

Pricing Tier Architecture

Community Tier (FREE)

Target: Individual users exploring the platform

Limits:

AI Workflow Runs: 10/month (all workflows combined)
Storage: 100MB total
History: 30 days retention
Collaboration: Solo workspace only

Per-Persona Access:

Students: 10 submissions/month, basic AI feedback, personal dashboard
Coaches: 1 class (max 10 students), 5 assignments/month, auto-publish grading only
Parents: Monitor 1 child, monthly AI summaries
Admins: Manage own organization only

Team Tier ($29/month per user)

Target: Small schools, homeschool co-ops, tutoring centers

Limits:

AI Workflow Runs: 100/month per user
Storage: 10GB per user
History: Unlimited
Collaboration: Team workspaces with permissions

Enhanced Access:

Students: Unlimited submissions, full AI evaluations, peer collaboration
Coaches: Unlimited classes, advanced grading (review queue, bulk actions), team workspace
Parents: Monitor 3 children, weekly reports, coach messaging
Admins: Multi-coach management, org analytics

AI Workflows:

Automated Grading: 100 uses/month (full control)
Parent Communication: 50 emails/month
Learning Paths: 20 generations/month
Assignment Creation: 20/month

Enterprise Tier (Custom pricing, $500+/month)

Target: Schools, districts, large organizations

Features:

Everything unlimited
SSO/SAML integration
Custom AI model fine-tuning
White-label platform
API access
Dedicated account manager

Database Schema Changes

New Tables

// Core subscription management
model Subscription {
  id                String             @id @default(uuid())
  userId            String             @map("user_id")
  tier              SubscriptionTier   // COMMUNITY, TEAM, ENTERPRISE
  status            SubscriptionStatus // ACTIVE, CANCELLED, etc.
  billingInterval   BillingInterval?   // MONTHLY, YEARLY

  // Stripe fields
  stripeCustomerId      String?  @unique
  stripeSubscriptionId  String?  @unique

  // Dates
  currentPeriodStart    DateTime
  currentPeriodEnd      DateTime
  trialEnd              DateTime?

  usageRecords      UsageRecord[]
}

// Usage tracking
model UsageRecord {
  id             String       @id @default(uuid())
  subscriptionId String
  userId         String
  feature        FeatureFlag  // AI_GRADING, PARENT_COMMUNICATION, etc.
  count          Int          @default(1)
  periodStart    DateTime
  periodEnd      DateTime
}

// Feature limits per tier
model FeatureLimit {
  id          String           @id @default(uuid())
  tier        SubscriptionTier
  feature     FeatureFlag
  monthlyLimit   Int?  // null = unlimited
  enabled        Boolean @default(true)
}

// Workspaces
model Workspace {
  id              String   @id @default(uuid())
  name            String
  type            WorkspaceType  // PERSONAL, TEAM, ORGANIZATION
  ownerId         String
  members         WorkspaceMember[]
  resources       WorkspaceResource[]
}

// Workspace membership
model WorkspaceMember {
  workspaceId   String
  userId        String
  role          WorkspaceRole  // OWNER, ADMIN, MEMBER, VIEWER
  permissions   WorkspacePermission[]  // VIEW, COMMENT, EDIT, etc.
}

// Shared resources in workspace
model WorkspaceResource {
  id            String
  workspaceId   String
  resourceType  ResourceType  // ASSIGNMENT, SUBMISSION, FILE, etc.
  resourceId    String  // ID of the actual resource
}

// AI workflow execution history
model WorkflowExecution {
  id              String
  userId          String
  workflowType    WorkflowType  // AUTOMATED_GRADING, etc.
  inputData       Json
  outputData      Json?
  status          ExecutionStatus  // PENDING, RUNNING, COMPLETED, FAILED
  tokensUsed      Int?
  executionTime   Int?  // in ms
  startedAt       DateTime
  completedAt     DateTime?
}

Key Enums:

FeatureFlag: AI_GRADING, PARENT_COMMUNICATION, LEARNING_PATHS, ASSIGNMENT_CREATION, TEAM_WORKSPACE, BULK_OPERATIONS, etc.
WorkflowType: AUTOMATED_GRADING, PARENT_COMMUNICATION, LEARNING_PATH, ASSIGNMENT_CREATION

Critical Backend Services

1. Subscriptions Service

File: stemblockai-backend/src/subscriptions/subscriptions.service.ts

Key Methods:

getCurrentSubscription(userId) - Get active subscription with usage
hasFeatureAccess(userId, feature) - Check tier-based access
checkUsageLimit(userId, feature) - Check quota, return remaining
recordUsage(userId, feature) - Track feature usage
upgradeSubscription(userId, newTier) - Stripe-powered upgrade

2. Feature Gate Guard

File: stemblockai-backend/src/subscriptions/guards/feature-gate.guard.ts

Usage:

@Post(':id/evaluate')
@UseGuards(JwtAuthGuard, FeatureGateGuard)
@RequireFeature(FeatureFlag.AI_GRADING)
async generateEvaluation(@Param('id') submissionId: string) {
  await this.subscriptionsService.recordUsage(req.user.id, FeatureFlag.AI_GRADING);
  return this.evaluationsService.generateEvaluation(submissionId);
}

Throws ForbiddenException when quota exceeded, includes upgrade prompt.

3. Workspaces Service

File: stemblockai-backend/src/workspaces/workspaces.service.ts

Key Methods:

createPersonalWorkspace(userId) - Auto-created on registration
createTeamWorkspace(ownerId, name) - Team tier required
addMember(workspaceId, userId, role, permissions) - Invite to workspace
shareResource(workspaceId, resourceType, resourceId) - Share assignments/files

Four New AI Workflows

Workflow 1: Automated Grading

File: stemblockai-backend/src/workflows/automated-grading/automated-grading.service.ts

Community Tier:

Auto-triggers on submission (uses 1 of 10/month quota)
Basic feedback only
Auto-publishes (no review)

Team/Enterprise Tier:

Configurable trigger (immediate/batch/manual)
Review queue with bulk operations
Custom rubrics
Full AI feedback with coach override

Implementation:

Extends existing EvaluationsService
Adds review queue system
Batch processing for Team tier
Integration with workspace sharing

Workflow 2: Parent Communication Generator

File: stemblockai-backend/src/workflows/parent-communication/parent-communication.service.ts

Community Tier:

3 pre-built templates (5/month)
Copy to clipboard (manual send)

Team/Enterprise Tier:

Custom templates (50/month)
Direct email sending (SendGrid/Resend)
Bulk emails for entire class
Scheduled reports (weekly/monthly)
Email tracking (Enterprise)

Implementation:

AI generates personalized content from student data
Template management system
Email service integration
Bulk operations for Team tier

Workflow 3: Personalized Learning Paths

File: stemblockai-backend/src/workflows/learning-paths/learning-paths.service.ts

Community Tier:

View-only basic path (1 generation)
Shows next recommended assignment

Team/Enterprise Tier:

Full customization (20/month)
Interactive visualization
Coach can edit milestones
Skill gap analysis
Progress tracking

Implementation:

Performance analysis algorithm (category scores, trends)
AI-powered path generation
Visual path builder (frontend)
Coach customization tools

Workflow 4: Assignment Creation Assistant

File: stemblockai-backend/src/workflows/assignment-creation/assignment-creation.service.ts

Community Tier:

Not available

Team/Enterprise Tier:

AI-assisted creation (20/month)
Parameters: topic, difficulty, type, grade level
Generates: title, description, rubric, sample solution
Save to team workspace library
Reusable templates

Implementation:

LLM-powered generation
Template management
Workspace integration for sharing
Rubric builder

Workspace Redesign by Persona

Student Workspace

Personal (All Tiers):

My Assignments dashboard
Submission history
Progress tracker with gamification
Achievement badges

Team+ Additions:

Peer collaboration spaces
Share submissions with classmates
Group project workspaces
Skill tree visualization
Comparison to class averages

Coach Workspace

Personal (All Tiers):

My Classes dashboard
Assignment creation
Review queue
Personal assignment library

Team+ Additions:

Coach team workspace
Shared assignment library (all coaches in org)
Collaborative grading
Team analytics
Coach-to-coach messaging

Parent Workspace

Personal (All Tiers):

Children dashboard
Progress overview
Published evaluations viewer

Team+ Additions:

Monitor up to 3 children (Team) or unlimited (Enterprise)
Weekly AI reports
Direct coach messaging
Comparison across children
Customizable alerts

Admin Workspace

Personal (All Tiers):

User management
Basic analytics
Billing management

Team+ Additions:

Multi-coach management
Organization-wide analytics
Bulk user operations
Custom role definitions (Enterprise)
API key management (Enterprise)

Implementation Phases

Phase 1: Foundation (Weeks 1-3)

Goal: Set up pricing infrastructure and feature gating

Week 1: Database Schema

Create all new tables (Subscription, UsageRecord, FeatureLimit, Workspace, etc.)
Update User model with subscription relation
Seed feature_limits with tier definitions
Test migrations

Week 2: Subscription Service

Create SubscriptionsModule and Service
Implement FeatureGateGuard and @RequireFeature decorator
Add subscription endpoints (GET /me/subscription, POST /subscriptions/upgrade)
Unit tests

Week 3: Workspace Service

Create WorkspacesModule and Service
Implement workspace endpoints
Auto-create personal workspaces on registration
Unit tests

Critical Files:

stemblockai-backend/prisma/schema.prisma
stemblockai-backend/src/subscriptions/subscriptions.service.ts
stemblockai-backend/src/subscriptions/guards/feature-gate.guard.ts
stemblockai-backend/src/workspaces/workspaces.service.ts

Phase 2: Frontend Tier UI (Weeks 4-5)

Goal: Build pricing pages and upgrade flows

Week 4: Pricing Page

Create pricing page with tier comparison
Build subscription management dashboard
Add usage indicators to all dashboards
Build upgrade modals/CTAs

Week 5: Stripe Integration

Set up Stripe products and prices
Implement StripeService
Create checkout session endpoint
Handle Stripe webhooks (subscription events)
Test payment flow

Critical Files:

stemblockai-frontend/app/pricing/page.tsx
stemblockai-frontend/components/dashboard/UsageIndicator.tsx
stemblockai-frontend/components/modals/UpgradeModal.tsx
stemblockai-backend/src/billing/stripe.service.ts

Phase 3: Workspace Features (Weeks 6-8)

Goal: Build collaborative workspaces

Week 6: Personal Workspaces

Student/Coach/Parent/Admin personal workspace dashboards
Workspace settings

Week 7: Team Workspaces

Create team workspace functionality
Invite members, permissions management
Shared assignment library

Week 8: Collaboration Features

Peer review system
Comments and annotations
Activity feed
Notifications system

Critical Files:

stemblockai-frontend/app/[role]/workspace/page.tsx (for each role)
stemblockai-frontend/app/coach/workspace/team/page.tsx
stemblockai-backend/src/collaboration/peer-reviews.service.ts

Phase 4: AI Workflows (Weeks 9-12)

Goal: Build 4 new AI workflow systems

Week 9: Automated Grading Workflow

Backend service with review queue
Bulk grading operations
Frontend grading panel for coaches
Workflow configuration UI

Week 10: Parent Communication Generator

Backend service with email integration
Template management
Frontend communication panel
Bulk communication UI

Week 11: Personalized Learning Paths

Backend service with performance analysis
Path generation with LLM
Frontend visualization
Coach customization interface

Week 12: Assignment Creation Assistant

Backend service with template management
Rubric generation
Frontend creation wizard
Workspace integration

Critical Files:

stemblockai-backend/src/workflows/automated-grading/automated-grading.service.ts
stemblockai-backend/src/workflows/parent-communication/parent-communication.service.ts
stemblockai-backend/src/workflows/learning-paths/learning-paths.service.ts
stemblockai-backend/src/workflows/assignment-creation/assignment-creation.service.ts
Frontend workflow UIs for each

Phase 5: Polish & Launch (Weeks 13-14)

Goal: Testing, migration, and launch

Week 13: Testing

End-to-end testing
Load testing (concurrent AI requests)
Security audit
Cross-browser and mobile testing
Accessibility audit

Week 14: Migration & Launch

Migrate all existing users to COMMUNITY tier
30-day grace period (unlimited access)
Send announcement emails
Launch pricing page
Monitor for issues

Migration Strategy

Existing Users

Default tier: All existing users → COMMUNITY tier
Grace period: 30 days of unlimited access to explore features
After grace period: Enforce COMMUNITY tier limits (10 AI runs/month)

Migration Script

# Run migration
npm run migrate:users-to-community

Creates COMMUNITY subscription for all users without subscriptions.

Communication Plan

Pre-Launch (1 week before):

Email: "Introducing New Features: Team Workspaces & AI Workflows"
Announce pricing tiers, reassure existing users

Launch Day:

Email: "New Features Are Live! Explore Your Free COMMUNITY Tier"
Highlight new features, explain limits
Offer launch discount (20% off Team tier for 3 months)

Post-Grace Period:

Email: "Heads Up: Your Monthly AI Quota Resets Soon"
Remind current usage, suggest upgrade

Harvey.ai Insights (Contrast)

Harvey's Approach:

Enterprise-only, no free tier
Sales-led growth (high-touch)
Deep customization per customer
$100K+ per customer
500+ customers, $50M ARR

StemBlock AI's PLG Approach (Opposite):

Freemium with self-serve upgrades
Product-led growth (low-touch)
Standardized features with templates
$29-500/month per user
Target: Thousands of users via viral adoption

Key Lessons:

Harvey left market share on table by avoiding freemium
PLG requires lower customization, higher standardization
Community features drive network effects (Harvey doesn't have)
Self-serve checkout essential (Harvey requires sales calls)

Critical Files Summary

Backend (Most Important)

stemblockai-backend/prisma/schema.prisma - Database foundation
stemblockai-backend/src/subscriptions/subscriptions.service.ts - Core subscription logic
stemblockai-backend/src/subscriptions/guards/feature-gate.guard.ts - Feature access control
stemblockai-backend/src/workflows/automated-grading/automated-grading.service.ts - Highest-value workflow
stemblockai-backend/src/workspaces/workspaces.service.ts - Collaboration foundation

Frontend (Most Important)

stemblockai-frontend/app/pricing/page.tsx - Primary conversion point
stemblockai-frontend/components/dashboard/UsageIndicator.tsx - Drives upgrade intent
stemblockai-frontend/components/modals/UpgradeModal.tsx - Self-serve upgrade flow
stemblockai-frontend/components/coach/AutomatedGradingPanel.tsx - Key workflow UI
stemblockai-frontend/app/settings/subscription/page.tsx - Subscription management

Success Metrics

PLG Metrics to Track:

Free-to-paid conversion rate (target: 5-10%)
Time to first value (target: < 5 minutes)
Feature adoption rate (AI workflows)
Monthly Active Users (MAU) growth
Average Revenue Per User (ARPU)
Net Revenue Retention (NRR)
Product Qualified Leads (PQLs) - users hitting quota limits

Tier Distribution Goal:

Community: 80% of users (broad adoption)
Team: 15% of users (primary revenue)
Enterprise: 5% of users (high-value accounts)

Next Steps

Review this plan with stakeholders
Set up development environment (local Stripe test mode)
Start Phase 1, Week 1: Database schema implementation
Establish weekly checkpoints for progress review
Prepare migration communications for existing users

This plan transforms StemBlock AI into a modern PLG SaaS while preserving the quality of the existing AI evaluation system.

Executive Summary​

Pricing Tier Architecture​

Community Tier (FREE)​

Team Tier ($29/month per user)​

Enterprise Tier (Custom pricing, $500+/month)​

Database Schema Changes​

New Tables​

Critical Backend Services​

1. Subscriptions Service​

2. Feature Gate Guard​

3. Workspaces Service​

Four New AI Workflows​

Workflow 1: Automated Grading​

Workflow 2: Parent Communication Generator​

Workflow 3: Personalized Learning Paths​

Workflow 4: Assignment Creation Assistant​

Workspace Redesign by Persona​

Student Workspace​

Coach Workspace​

Parent Workspace​

Admin Workspace​

Implementation Phases​

Phase 1: Foundation (Weeks 1-3)​

Phase 2: Frontend Tier UI (Weeks 4-5)​

Phase 3: Workspace Features (Weeks 6-8)​

Phase 4: AI Workflows (Weeks 9-12)​

Phase 5: Polish & Launch (Weeks 13-14)​

Migration Strategy​

Existing Users​

Migration Script​

Communication Plan​

Harvey.ai Insights (Contrast)​

Critical Files Summary​

Backend (Most Important)​

Frontend (Most Important)​

Success Metrics​

Next Steps​

Executive Summary

Pricing Tier Architecture

Community Tier (FREE)

Team Tier ($29/month per user)

Enterprise Tier (Custom pricing, $500+/month)

Database Schema Changes

New Tables

Critical Backend Services

1. Subscriptions Service

2. Feature Gate Guard

3. Workspaces Service

Four New AI Workflows

Workflow 1: Automated Grading

Workflow 2: Parent Communication Generator

Workflow 3: Personalized Learning Paths

Workflow 4: Assignment Creation Assistant

Workspace Redesign by Persona

Student Workspace

Coach Workspace

Parent Workspace

Admin Workspace

Implementation Phases

Phase 1: Foundation (Weeks 1-3)

Phase 2: Frontend Tier UI (Weeks 4-5)

Phase 3: Workspace Features (Weeks 6-8)

Phase 4: AI Workflows (Weeks 9-12)

Phase 5: Polish & Launch (Weeks 13-14)

Migration Strategy

Existing Users

Migration Script

Communication Plan

Harvey.ai Insights (Contrast)

Critical Files Summary

Backend (Most Important)

Frontend (Most Important)

Success Metrics

Next Steps