The longest day, the brightest year

A solstice reflection on a year of AI teacher coaching at scale

Today is the summer solstice, the longest day of the year in the northern hemisphere. It is also, by our own choosing, STAR21’s company day.

We picked this date deliberately. The solstice is a moment of maximum light, and a natural point to pause, take stock and look ahead before the next season of work begins. For a company built around feedback and growth, that felt like the right rhythm to keep.

STAR21 was founded on 1 April 2025, which makes today our second company day, and the second time we have stopped to ask the same question. What did we learn, and where do we go next.

Where Starlight started

A little over a year ago, Starlight was only an idea, and a slightly frustrated one at that.

Schools invest enormous time, energy and money in professional development, yet the feedback teachers actually receive is rarely specific, timely, actionable and regular enough to change practice. That observation became our mission: to make high-quality feedback specific, timely, actionable and regular, at scale.

Since then we have traveled further than we expected. Hundreds of teachers across a growing number of schools, now in several countries and across Europe and Asia as well as the UK, have used Starlight to turn whole-lesson recordings, in more than 70 languages, into private coaching reports. We record the whole lesson rather than short clips because context matters in AI coaching. Thousands of pages of transcript later, the central idea has held up. Transcript-based coaching works, and teachers find it useful.

The feedback we value most is not about the technology. It is what teachers tell us about their own practice: that a report felt personal, that it surfaced something they had not noticed in the moment, that they changed something the very next lesson. For a company whose whole purpose is feedback, there are few better signs.

Why teacher trust comes first

If there is one word beneath everything we do, it is trust.

Our framework is built on it. We talk about STAR feedback: specific, timely, actionable and regular. But the acronym only earns its place if teachers believe the platform is on their side. We have written before about why trust matters more than hype, and the principle holds. Coaching reports are private by default. Leadership only ever sees anonymised, aggregated trends. Teachers keep control of their own recordings. None of that is decoration. It is the condition that makes everything else possible.

It is also why we chose the name Starlight. The light belongs to teachers and our teachers are the stars. The platform’s only job is to help them see their own practice more clearly.

Why we stay focused

As we have grown, we are asked often whether STAR21 will expand into assessment, planning, curriculum, behaviour, data tracking, student tools and the rest. The answer is usually the same. Not yet.

Earlier this year I wrote a short essay on the virtues of focus. The argument is simple. Enduring companies tend to do one thing exceptionally well rather than many things adequately, and the discipline to stay focused is harder than the temptation to chase every opportunity.

For STAR21, that one thing is feedback. Everything we build has to serve it, helping schools create meaningful professional growth and helping teachers improve without adding to their workload. When a new idea does not pass that test, it waits.

The next constellation: aggregated insight for school leaders

While teachers take a well-earned summer break, our building does not stop.

The project I am most excited about is currently in beta: Deep Field Reports. The name is borrowed from astronomy. When the Hubble telescope was pointed at a patch of sky that looked empty, a long exposure revealed thousands of galaxies that had been there all along, unseen. A school’s transcript library is much the same. Most of what it could tell us goes unnoticed, simply because no one has had a way to look at all of it at once.

Individual coaching stays private, always. But when transcripts are anonymised and aggregated, clear patterns emerge across a school or trust. Themes around questioning, participation, retrieval, explanation and classroom discourse become visible at the level of the whole community, never the individual. Leaders can ask a question of their transcript library in plain language and receive a qualitative, thematic answer, with no way to trace it back to a particular person.

The purpose is understanding, not accountability. It helps leaders to query their transcript library and decide where to focus coaching and professional development, without ever exposing a single teacher, department or classroom. The reports are built so they cannot single anyone out, because the moment a tool like this can identify an individual, the trust that makes it useful disappears. A single star tells you something. The wider constellation often tells you more.

From Wiltshire, with patience

It feels fitting that all of this began in Wiltshire, and that we remain a Wiltshire company. This is, after all, the county of Stonehenge, built by people who watched the sun with extraordinary care, and who marked this exact day thousands of years before us. We are doing something far smaller, but in a similar spirit: paying close attention to patterns, and trying to build something that lasts.

Looking ahead: AI and the future of teacher development

The opportunity remains substantial. There are tens of thousands of schools across the UK alone, and professional development is still one of the most important and under-resourced challenges in education. The evidence base, including the EEF Teaching and Learning Toolkit, is clear that sustained, well-designed development changes practice. Advances in AI are making genuinely new forms of feedback possible.

We are optimistic about that, carefully so. The future of AI in education is not something to let happen to us. It is something to shape, with professional judgement, privacy and teacher autonomy built in from the start. There is a great deal more coming this year, including an international research pilot with a leading university that we will say more about soon.

If you lead a school or trust and want to see how transcript-based coaching works in practice, you can book a demo and we will walk you through it.

I want to thank everyone who has helped us reach our second Company Day: every teacher, leader, governor, partner and adviser who has believed in the idea and supported us along the way. Most of all, thank you to our friends and families for their patience, encouragement and unwavering support, and for putting up with the long hours, late nights and occasional obsession that come with building something from the ground up. We simply would not be here without you.

As the sun sets

The solstice is a useful reminder that growth rarely arrives in dramatic leaps. It accumulates, lesson by lesson and reflection by reflection, until one day the change is plain to see.

As the longest day draws to a close, we are grateful, and we are only getting started.

Spark Insight with Starlight, and discover the power of doing one thing brilliantly.

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The Insight Engine is written by Adam Sturdee, co-founder of Starlight, the UK’s first AI-powered coaching platform, and a senior leader with responsibility for teaching, learning and coaching. This blog is part of a wider mission to support educators through meaningful reflection, not performance metrics. It documents the journey of building Starlight from the ground up, and explores how AI, when shaped with care, can reduce workload, surface insight, and help teachers think more deeply about their practice. Rooted in the belief that growth should be private, professional, and purposeful, The Insight Engine offers ideas and stories that put insight, not judgment, at the centre of development.

🔗 Connect with me on LinkedIn: https://www.linkedin.com/in/adam-sturdee-b0695b35a/