# Technical requirements document

Concept · [Product](https://ecosystem.samcarlton.com/product)

Also called: TRD, TRDs, technical spec, tech spec, design doc

A document that explains how a feature will be built: the systems, data and technical choices. It usually follows the [product requirements document](https://ecosystem.samcarlton.com/product-requirements-document).

**For example:** The TRD says invoices will be stored in the existing [database](https://ecosystem.samcarlton.com/database) and sent through the payment provider's [API](https://ecosystem.samcarlton.com/terms/api).

## Connects to (4)

- [Product requirements document](https://ecosystem.samcarlton.com/product-requirements-document): A document that explains what a product or feature should do, for whom and why, so the team agrees before building.
- [Data model](https://ecosystem.samcarlton.com/data-model): The plan for what information an app stores and how the pieces relate, such as customers, orders and products and which belongs to which.
- [API contract](https://ecosystem.samcarlton.com/api-contract): An agreement on exactly what requests an API accepts and what responses it returns.
- [Tech stack](https://ecosystem.samcarlton.com/tech-stack): The set of programming languages and tools a product is built with.

Map view: https://ecosystem.samcarlton.com/technical-requirements-document