About me
I like the parts of a product that break when real people use it.
I'm Mehedi Hasan Sarkar, a full-stack engineer based in Dhaka, Bangladesh. For more than four years, I have built web and mobile products for clients in Australia, Sweden and the UK. These include court booking platforms, the booking system of a salon with several branches, a student management platform for training providers, learning apps and a finance portal.
years since 2021
clients I have built for, all remote
front end to back end
Principles
How I build
Start from what can go wrong
Two users book at the same moment. A payment event arrives twice. A worker stops halfway. I list these failures before I build the feature.
The server decides
Price, availability and permissions are checked on the server. An app can show old data, and a request can be changed before it arrives.
Hold the money first
The card is authorised when the customer books. The money is captured close to the booking time. So a cancellation before that is not a refund.
Done means done
A reminder is marked as sent only after it is delivered. A job shows as paid only after Stripe confirms the payment.
Tools
What I work with
Frontend
- Next.js
- React
- TypeScript
- TanStack Query
Backend
- Node.js
- Express
- TypeScript
- MongoDB
- Redis
- BullMQ
Mobile
- React Native
- Expo
- Firebase
My story
The longer version
I enjoy the problems that are easy to miss. Two customers book the same slot. A payment event arrives twice. A report must pass a government validator. I start by naming what can go wrong. Then I build the simplest solution that handles it.
I have led a mobile team of three developers on two products. I have handled App Store and Google Play releases, and I have guided junior developers on client work.
Want to talk about your product?
Tell me about your product and what is blocking it. I will reply with how I would approach it.