Building Thea: an agent that does a consultant's slide work
How we took one of the most time-consuming parts of consulting (turning thinking into polished, on-template slides) and designed an agent that does it to a standard a partner would sign off.
The last mile of consulting is formatting
In consulting and corporate strategy teams, the thinking is often finished long before the deck is. What's left is slow, manual work: rebuilding slides on each client's template, aligning boxes, matching fonts and fixing icons, usually late in the evening before a deadline.
The AI tools we tried didn't solve it. They produced pictures of slides, or slides in their own style, which then had to be rebuilt by hand. The brief for Thea was simple to say and hard to meet:
- Native: real PowerPoint shapes, text and charts, never a picture.
- On the client's template: their colours, fonts and layouts.
- Good enough to send: aligned, consistent and clean, without a redo.
- Safe on a corporate laptop: locked-down machines, strict IT, sensitive material.
We designed Thea like a small team, not a single tool
Just as we would design roles in an organisation, we broke the work into clear jobs, each with its own responsibility and quality check.
Understand
Read the brief, split a multi-slide request into separate slides, and work out what each slide needs to say.
Design
Decide the layout: cards, timelines, charts, what gets emphasis, and how it fits the template.
Build
Build the slide natively in PowerPoint on the client's own template, with consistent line icons.
Check
A final review for alignment, gaps, icon placement and sizing, fixed before the user ever sees it.
Five design decisions that made the difference
One engine, shared by two products
The web app and the desktop app use the same design engine rather than two copies. An early attempt with two copies drifted apart within days. Now one improvement reaches both products at once.
Keys never touch the laptop
Every call that needs an access key goes through one secured service. The desktop app holds none. Each user has their own access, which can be switched off centrally within about a minute.
Say less
Users see progress and results, not the machinery. Internal steps, scores and settings never reach the screen. That keeps the experience simple and protects how the product works.
A thinking space that can't spend
Chat mode was designed so it cannot build anything. Consultants can work out an argument freely, without accidentally using up the slide allowance their team needs.
Tested on real work, not demos
More than 3,000 automated tests, plus real builds checked against the designs they came from. Faults that only show up on a rendered slide were found this way and fixed for good.
"An absent icon beats a wrong one."One of the rules built into Thea: if it can't find the right icon, it leaves the space empty and says so, rather than guessing.
What a Thea slide looks like
Built from a two-line brief, on the client's template, with every element editable.
- 1Editable textTitles, labels and takeaways are real text boxes.
- 2A real chartChange the numbers and the chart updates.
- 3The client's templateColours, fonts, footer and page numbers come from their own template.
From a brief to a finished deck
Thea now creates single slides or whole decks from one brief, redesigns chosen slides of an existing deck in place, rebuilds a slide from a design image, and gives consultants a chat space to think before they build.
- Web app with secure sign-in and multiple builds running at once
- Windows desktop app that works live in PowerPoint, Excel and Word
- Handles decks of up to 250 slides
- Runs on locked-down corporate laptops, without admin rights
- Generated files deleted automatically after 30 days
Four lessons we bring to every agent we design
Pick work with a clear standard
Thea works because "a good slide" can be defined and checked. The best first agent in your organisation is work where "good" is equally clear.
Design the checks, not just the task
The final alignment review matters as much as the build. Every agent needs a built-in way to catch its own mistakes.
Security is a design choice
Keeping keys off devices and giving each user an off-switch was decided on day one, not added after an audit.
People stay the authors
Thea builds; the consultant decides what the slide says. The agent takes the formatting, and people keep the judgement.
What would your organisation's "Thea" be?
Let's find the work in your business that an agent should take on, and design it properly.