Case study
InstaSDR
AI-Powered Sales Development Platform
Role
Scope
Stack
What I built.
- 01
Worked on the core platform and its AI features: researching a company, building buyer and seller personas, and writing outreach emails and follow-ups that fit the context.
- 02
Built the whole billing experience on Stripe: customers pick a plan, pay through Stripe Checkout and get their own allowance of campaigns, emails, sequences and workspaces.
- 03
Plan changes carry unused credits over, so nobody loses what they paid for, and customers can buy extra email credits without changing plan.
- 04
Usage is tracked against each allowance; at the limit the platform stops with a clear message instead of failing silently.
- 05
Allowances reset automatically on renewal, and a failed payment pauses the subscription until it is resolved.
- 06
Tuned the AI per task, so creative writing and analytical work each get the right model and settings: better output, more consistent, and cheaper to run.
- 01
Built features across a TypeScript monorepo: a Next.js 14 app with API routes and typed Supabase access, plus Node.js services for the email queue (AWS SQS), email sync and CRM sync.
- 02
Integrated LangChain through a shared prompts package used by both the app and the services: campaign intelligence, company research, email generation and reply sentiment classification.
- 03
Stripe Checkout for plan purchases and changes, one-time checkout for credit top-ups, and a signature-verified webhook handling checkout.session.completed, invoice.created and invoice.payment_failed.
- 04
State-driven billing on an is_default active-subscription pattern that keeps full history; upgrades and downgrades cancel the old Stripe subscription and carry the remaining credits onto the new plan.
- 05
Usage enforcement that rejects over-limit requests with logged errors; renewals reset usage counters and restore credits to the plan’s limits.
- 06
Centralised model setup in a shared LLM factory with per-workflow temperature, choosing models by cost, latency and quality; Vitest suites cover subject and body generation.