SaaS

SoldComps

Built and run a real-time sold listings API: one request returns up to 240 real sales from eBay, Poshmark, Mercari, and TCGPlayer, sold via self-serve SaaS, RapidAPI, and Apify.

Project Details

Client

CafDev Studio (in-house product)

Duration

Ongoing

My Role

Founder and sole engineer: product, architecture, backend, frontend, billing, infrastructure, and customer support.

Key Highlights

500+ paying customers out of 2,500+ users
Up to 240 sold listings per request, across 4 marketplaces
Self-serve sign-up, API keys, and Stripe usage billing

Project Goals

1
Give resellers and developers real sold prices, not asking prices or estimates
2
Return reliable data: fail cleanly rather than return partial or incorrect results
3
Charge only for results, so failed requests are never counted against a plan
4
Scale from hobby users to high-volume enterprise customers

Development Process

Product definition around one clear promise: one request, up to 240 sold listings

API and data model design

Backend services, job queues, and data pipeline

Data quality checks and response validation

Dashboard, docs, and billing integration

Launch on direct SaaS, RapidAPI, and Apify

Ongoing expansion to new marketplaces

Technologies Used

Tech Stack

Technologies we used to build a robust and scalable solution

React

Node.js

MongoDB

AWS

Redux

TypeScript

Project Impact

Results & Impact

500K+

API Requests Served Daily

500+

Paying Customers

2,500+

Registered Users

Let's Work Together

Ready to Start Your Project?

Let's build something amazing together. I bring the same level of expertise and dedication to every project.