Sabuj Biswas
Biotechnologist · Web & app builder

Websites, apps and data tools, built by a scientist.

I build websites for labs, researchers, clinics and small biotech or agro businesses, and I turn messy PDFs and spreadsheets into clean data. I work in molecular biology and genomics myself, so I understand your content and you spend less time explaining it.

Get a free quote See my work

I work in English and বাংলা

What I can do for you

Small, clear projects at a fixed price that I quote before any work starts.

Websites for labs & businesses

  • Research group, lab, clinic or company sites
  • Services, team, publications, contact pages
  • Mobile-friendly, fast, free hosting setup
  • Domain and accounts in your name

Android & web apps

  • Simple apps for training, quizzes or records
  • Bengali and English interfaces
  • Online database and user login

Research data support

  • Pull tables and text out of PDFs into Excel
  • Clean and organise datasets
  • Figures and basic analysis in Python
  • Manuscript and reference formatting

Recent work

Real projects, built and maintained by me.

Own product · Education · smartprepbd.com

SmartPrep BD

An exam-preparation website and Android app for university admission and job exams in Bangladesh, fully in Bengali.

  • Practice from past papers, daily live exams with merit lists, and progress analytics
  • Python pipeline that extracts question banks, images and formulas from PDFs
  • Google sign-in, answers graded on the server, Google-friendly pages for every past paper
  • Over 240 automated tests across the app and website
FlutterNext.jsSupabasePython
Own product · Personal finance · Android

Tohobil তহবিল

A private money app for Bangladesh: cash, bank and bKash in one place, in English or Bengali.

  • Paste a bKash or Nagad SMS and the entry fills itself, fee included
  • Budgets with a plain-language forecast, savings goals, debts with WhatsApp reminders
  • Monthly report picture to share, home-screen widget, lakh-style amounts and Bengali digits
  • Works offline, fingerprint lock, password-encrypted backups to the user's own Google Drive

Read the case study ↓

KotlinJetpack ComposeRoomWorkManager

Case study: Tohobil তহবিল

I took an expense tracker that had plenty of features but felt rough, and rebuilt it screen by screen into an app a Bangladeshi family could use every day.

The starting point

The app worked, but it looked like a default template, every text was in English only, amounts weren't in the lakh style people here read, and some features nobody needed were mixed in with the ones people use daily.

What I changed

  • Cut it down to four clear tabs: Home, Transactions, Plan and Insights.
  • Made a small design system (colours, type, amount styles, shared parts) and rebuilt every screen on it, in light and dark mode.
  • Every screen in English and Bengali, amounts in lakh style, and Bengali digits in Bengali mode.
  • Plain words instead of jargon: “At this pace you will spend about ৳8,913 this month”, and no more “Spending Velocity”.
  • A three-step first-run setup: language, where you keep your money, optional fingerprint lock.

Made for Bangladesh

  • Copy a bKash, Nagad or Rocket message and paste it: amount, accounts, date and transaction ID are filled in, and a cash-out fee is saved as its own expense. No SMS permission needed.
  • “Remind” on money someone owes you opens WhatsApp with a polite message and the amount left.
  • A monthly report picture in English or Bengali to send to family.
  • A home-screen widget with this month's spending and a quick + button.

Problems found and fixed on the way

  • Restoring the wrong file wiped all data. Now the file is checked first.
  • Backups only opened on the phone that made them. Now they are locked with the user's own password (AES-GCM), so they move to a new phone.
  • Recurring bills could save dates in Bengali digits and only caught up one missed payment.
  • Spending in a sub-category didn't count toward its budget.
  • The release build could not be made at all. Fixed and brought up to Android 16 for Google Play.

Everything stays on the phone: no account, no ads, no tracking. Privacy policy

  • 4clear tabs
  • 2languages
  • 58automated tests
  • 10screens redesigned
Home screen: total balance ৳2,00,950, accounts, spending this month
Home: every account and this month at a glance
Add entry screen with a large ৳450 amount and category tiles
Add an entry in a few taps
Insights: this month's spending compared with last month, day by day
Insights: this month against last
Home screen in dark mode
Dark mode

How I work

Simple and transparent, with no surprises and no lock-in.

  1. Free chatYou tell me what you need and I ask a few questions.
  2. Written quotePrice, what's included and the timeline, by email or WhatsApp.
  3. 50% to startYou pay the rest when you're happy with the result.
  4. You own itDomain, hosting and accounts stay in your name.

Have a project in mind?

Send me a short message about what you need. I usually reply within a day.

Email me