Eng Sutra
From a calculator app engineers used once, to an exam-prep platform they come back to every day.
Eng Sutra started as a toolbox that gave civil engineers 120+ calculators and a BOQ builder. It was useful, but people opened it, got a number and left. I led the design to rebuild it into a daily-use platform: every tool kept, plus a dashboard, an MCQ bank with a readiness score for the Nepal Engineering Council license exam, a better e-book reader, bookmarks and accounts.
- Role
- Product Designer
- Company
- Idea Associates
- Platform
- Web & mobile app
- Timeline
- 4 months
- Team
- 2 developers, 1 QA
- Tools
- Figma
What I owned: UX research, UX flows, UI, design system, prototyping and developer handoff.
Context
Eng Sutra was built for civil engineers, site supervisors, contractors, quantity surveyors, architects and students. It had calculators across nine categories, from Quantity & Material and RCC Structure to Conversions and Measurement Tools, plus a BOQ builder with Excel, PDF and WhatsApp export, e-books, favourites and history.
Many of those users were also preparing for the NEC license exam, the gate to professional practice in Nepal across 11 engineering faculties. The calculator app did nothing for them. That gap became Eng Sutra.
The problem
A calculator is a one-off utility. Exam candidates, meanwhile, had no single place to practice, measure readiness or find their weak areas.
Nothing pulled users back after a calculation.
PDFs, photos of past papers and group chats.
Candidates couldn’t tell how ready they were, how fast they answered, or which chapters held them back.
No saved progress across devices, and no path to a paid plan.
Users & goals
Needs structured practice, a pass-line score, weak-chapter guidance and quick access to codes.
Needs fast calculations on site, saved results, and a BOQ to share on WhatsApp.
Needs to learn by doing, with reference books and practice questions.
What success looks like
- Turn a utility into a daily-use platformReturning users per week, sessions per user
- Answer “Am I ready?”Mock tests completed, readiness score viewed
- Keep every existing tool under one accountCalculator users who also use MCQs or e-books
- Lay a foundation for a paid planSign-ups, upgrade clicks, referral code use
Constraints: a mixed audience from students to site professionals, so it had to be easy to learn; used on phones and laptops; content-heavy (120+ calculators, a large question bank, many e-books); and Nepal-specific needs like Rs. currency, local land units, rate schedules and NBC / DUDBC standards.
How I researched it
Before redesigning, I ran two kinds of research on the first version: user interviews and usability testing. The interviews showed how engineers and students actually used the app. The usability sessions showed where they hesitated, got lost or gave up.
Conversations with the people who use the app, covering how they calculate, study and keep track of what they need.
I watched people use version 1 for real tasks and noted every point of friction, from finding a calculator to saving something for later.
- Home became a dashboard that guides people, instead of a plain list of calculators.
- Calculators moved from one long page to a category and sub-category browse, and every calculator got a unit selector.
- One mixed favourites list became bookmarks with a tab for each feature, so saved items are easy to find.
Restructuring the product
The first version had a flat sidebar of seven items. The redesign regrouped it into two clear zones, with a profile menu, an Upgrade Plan button and one universal search across calculators, e-books, MCQs and BOQ templates.
- Home
- Calculators
- E-books
- BOQ
- Favourites
- History
- Settings
- Dashboard
- Calculators
- E-Books
- BOQ Builder
- MCQ Bank · new
- Bookmarks
- History
Calculators moved from one long page to a browse flow:
What changed, side by side
The same product, before and after the redesign. Each pair shows one problem I fixed.
Home
Calculators
Saved items
Key design decisions
Each decision started from a specific problem. Here are the ones that shaped the product most.
Rebuilt Home as a dashboard of intents
Four intent cards (Calculators, E-Books, BOQ Builder, MCQ Bank), a greeting, a 30-second tour and universal search. “Popular starting points” add social proof, so a new user always has an obvious next step.
A readiness score against the pass line
Each faculty gets one score measured against the pass line, broken down into correct-in-time, correct-but-slow, incorrect and skipped. Candidates get both a clear answer and a reason behind it.
A timer that counts up, not down
Mock tests record time per question without a panic-inducing deadline. The report shows pace alongside accuracy, and “Where to focus next” lists the weakest chapters with one-tap practice.
Kept the calculator pattern untouched
Grouped inputs, a unit toggle, Calculate and Reset, then results. Learn one calculator and you know them all. I changed what surrounded it instead, and added bookmark, share and report actions to every calculator.
Bookmarks organised with tabs, plus question reporting
At first every saved item landed in one jumbled list, and finding anything took too long. I added tabs (All, Calculators, E-Books, BOQ Builder, MCQ Bank) so each type of saved item has its own place, with sort on top. Everything is now sorted and easy to find, with no mess. A “Report a question” flow with clear issue types (incorrect answer, unclear question, missing option) keeps the question bank honest.
Low-friction onboarding with room to grow
Three intro slides, Google sign-in, guest mode with a clear “sign up to save your work” limit, password reset, and a referral-code step that lays the groundwork for growth and a paid plan.
Working with developers
I worked with the developers through the whole cycle: design handoff with annotated screens, and design QA before each release. When a developer flagged a constraint, I adjusted the design instead of defending it.
System & edge cases
The visual language moved from a plain utility look to a consistent product system of cards, tabs and sidebar navigation.
States I designed for
- Empty bookmarks and history, each with a next step
- “Not scored yet” readiness with two clear actions
- Guest mode limits: “Sign up to save your work”
- Delete and clear-history confirmations
- Full password reset flow
- Report-a-question with issue types
More screens
v1: nine categories with See More / See Less to keep long lists scannable.
Auto-calculated rows, VAT and contractor profit, with Excel, PDF and WhatsApp export.
Chapter drill with explanation after each answer.
The same flows on phone, for use on site.
Eng Sutra is live, with every calculator kept and a full exam-prep layer under one account.
What I learned
- A tool answers a question once; a journey answers it every day. Retention came from giving users a goal and a way to measure progress toward it.
- Keep what already works. The unchanged calculator pattern let existing users move over without relearning anything.
- I changed the MCQ flow after testing it with real users. My first design followed the usual pattern: tap an answer, tap Next, then the next question appears. When I watched candidates use it, that extra tap on every question added up across a full mock test. I changed it so tapping an answer moves straight to the next question, with a Previous button for anyone who taps the wrong option. Because Eng Sutra already tracks time per question, every saved tap gave candidates more of their exam time back. I worked the change through with the developers so the time tracking and the answer state stayed correct, and it made practice noticeably smoother.
- A long list stops working once people save a few things. Bookmarks were jumbled and hard to find until I split them into tabs by type, so organising content matters as much as saving it.
- Accessibility is also about forgiving mistakes, not only contrast and tap size. One clear action per question and an easy way back made the screen easier for everyone, especially on a phone.