Chapter 01 · basic · 4 min
Start here: Excel & this tutorial
You already have an opinion about Excel, and it's probably "office software, not a real skill." Here's the reframe this whole track is built on: since LAMBDA shipped in 2021, Excel's formula language is Turing-complete — Microsoft's own research team published the proof. You're not learning how to make a spreadsheet look tidy. You're learning a real, widely-used functional programming language whose IDE happens to be a grid of cells, and whose runtime is installed on more machines than any other language on earth.
Before the first real chapter, two quick things: how these lessons work, and what's actually calculating your formulas.
The grid
No grid needed yet — the first live formula is below.
Every example here is live: run it, then break it
This isn't a read-only tutorial. Every grid below is a real spreadsheet, connected to a real calculation engine. Click the cell below, type =1+1, and press Run — you'll get an actual computed value back, not a screenshot. Then change it: try =2*21, try ="a"&"b", try typing something with no = at all and see what happens. Nothing you do here can break anything, and experimenting is the fastest way to learn. Each chapter also ends with links into the Excel question bank, so the moment a concept clicks you can go practise it for real.
Before you run it — what do you expect `=1+1` to show in the cell?
| A | |
|---|---|
| 1 | =1+1 |
This tutorial runs a real spreadsheet engine, in your browser
The engine powering every example here is IronCalc, an open-source spreadsheet calculation engine running entirely inside your browser (no server, no signup, nothing to install) — the same category of engine that powers desktop Excel and Google Sheets, computing the same functions the same way.
Why call this out? Because spreadsheet tools have small differences at the edges (a function here, a keyboard shortcut there). The core you'll learn in this tutorial — references, IF, SUMIFS, lookups, dates, cleaning — is identical across Excel and Google Sheets and is what 95% of interview questions actually test. A handful of newer functions (XLOOKUP, FILTER, dynamic arrays) need a recent Excel 365 build; this tutorial flags those each time, because plenty of the banks and logistics firms you might interview with still run Excel 2019 or LTSC, where those functions don't exist yet.
Why an Excel track on a SQL interview-prep site
Not every analyst screen is a SQL screen. Finance, ops, and logistics roles across the region run day-to-day on spreadsheets, not databases — and a surprising number of "SQL interview" candidates also get handed a spreadsheet task in the same loop. The two skills rhyme constantly: SUMIFS is WHERE + GROUP BY in one formula, VLOOKUP is a JOIN, a pivot table is GROUP BY with a UI. If you've done the SQL chapters already, you'll recognise almost everything here; if you haven't, this track works standalone.
How the tutorial is structured
Chapters are grouped into three tiers you can see in the sidebar, meant to be read in order:
| Tier | What it covers |
|---|---|
| Basic | Writing a formula, referencing cells, and the functions everything else builds on |
| Intermediate | Lookups, error handling, and cleaning messy real-world data |
| Advanced | Dates, dynamic arrays, and building a full rollup from raw data to summary |
You can jump around with the sidebar any time, but if you're newer to spreadsheets, top-to-bottom is the intended path — each chapter builds on the ones before it.
That's the whole orientation. Next up: the one character that turns a cell from inert text into a live calculation.