How I Built an Internal Developer Platform in 6 Months
Platform engineering is transforming how enterprises ship software. Here is how I designed and built AgStack — a reusable IDP serving 11 products.
Why Build an IDP?
When you manage 11 products across real estate, communications, AI, eCommerce, and DevOps, every team reinventing the wheel becomes a bottleneck. Authentication, logging, validation, storage — each product had its own implementation. Duplication meant inconsistency, security gaps, and slower delivery.
The Approach
Instead of building another tool, I designed AgStack as an **Internal Developer Platform (IDP)** — a set of reusable, standardized modules that every product could consume as npm packages.
Core Modules
@agstack/auth — JWT-based authentication with RBAC, session management, and OAuth support
@agstack/logger — Structured logging with correlation IDs, log levels, and transport abstraction
@agstack/validation — Schema-based input validation using Zod with standardized error responses
@agstack/storage — Abstracted file storage supporting local, S3, and CloudFront
@agstack/security — Rate limiting, CSP headers, SQL injection prevention, CORS management
@agstack/plugin-sdk — Plugin system for extensibility
Results
Standardized security — every product gets auth, CSP, and rate limiting by default
Single upgrade path — update one package, all products benefit
Published to npm — teams consume via familiar package management