APIs & Services
Smart Reply Service
A backend service for generating reply drafts without burying the logic inside the app.
2023 / APIs & Services / Node.js / TypeScript / Fastify / Redis / OpenAI
Quick read
A clear breakdown of the product, the reasoning behind it, and the implementation choices that matter.
- Year
- 2023
- Category
- APIs & Services
- Status
- Maintained
Overview
Smart Reply Service is a backend service that generates context-aware reply drafts for messaging and support products. It keeps request shaping, response constraints, and service reliability in one place so reply suggestions can be integrated safely.
Why it exists
Reply generation gets hard to maintain when prompt logic, context assembly, and delivery all live inside the product codebase.
How it works
I pulled the capability into a dedicated service with typed request contracts, prompt policies, and response guards so downstream products could integrate it more safely.
Built with
Node.js / TypeScript / Fastify / Redis / OpenAI
What I focused on
- Built a stateless API layer with clear request and response schemas.
- Added prompt controls for tone, length, and exclusion rules.
- Used caching for repeated context assembly paths.
- Designed the service to plug into messaging and support workflows cleanly.
Where to look
Repository snapshot
- Repo
- Smart Reply Service
- Language
- TypeScript
- Updated
- Nov 29, 2025