A computing education platform for UK schools
A UK charity gives schools free computing courses in which students invent, design and build their own app. I was main developer on its platform, then led the build of the new one.
The programme
The charity’s courses teach young people to build technology for problems they care about. Students start from something in their own lives or community, turn it into an app idea, then design, build and test it as a team, over a series of lessons led by their teacher.
The current course is for students aged 11 to 14 and runs over 12 sessions. Students design and build an AI-powered app for a real-world challenge, either writing JavaScript or using AI-assisted coding tools. It is free for schools and written so that specialist and non-specialist teachers alike can teach it.
People from the tech industry join classes as volunteers. Each year, student teams can enter their apps into a national competition, where volunteers judge them and the strongest teams present at a final event.
Why the charity rebuilt its platform
The old platform, which I worked on for years, had grown into one large application that carried the website, the blog and the accounts teachers and volunteers used. The competition ran in a separate app, which I also worked on.
Each part worked, but together they were slow to change. The charity wanted one focused product for teaching, volunteering and the competition, on a clean codebase ready for the next decade of changes to its courses and to schools.
30,444 young people
in 708 schools took part in the programme in 2024/25.
- 860 teachers
- 296 volunteers from 47 tech companies
- 4,885 volunteer reviews of students’ app ideas
My role
For the new platform, I worked with a designer and the charity’s education and programme team. The charity’s team defined what the platform had to do and signed off each decision. I turned those needs into a product, planned the work and wrote the code.
Built around how students learn
The charity’s education team writes the courses. The platform’s job is to help any teacher deliver them well, including teachers who are not computing specialists.
Every lesson is broken into short steps, and each step has one purpose: setting out what students will learn, presenting slides, running an activity or checking understanding with a quiz. Alongside the material students see, the teacher gets guidance written for that step.
Modules open in order, so a class builds its skills in sequence instead of skipping ahead. Quizzes with a single right answer mark themselves, and open answers are passed to the teacher to review, so students get feedback on everything they submit.
Teachers set up each class with its year group and size, then see how far the class has got and what comes next. When a course is finished, students receive a certificate.
Hearing from teachers and students
After each lesson, the teacher answers a short check-in. If the lesson went ahead, they note what worked, what did not and what could be better. If it did not, they say why.
Students give their own feedback anonymously, on the course and on how confident they now feel with technology. Together, the two give the education team a lesson-by-lesson view of how each course is going in real classrooms.
The team can also see across all schools which courses are running, how far classes have got and how many volunteer sessions have taken place, without building spreadsheets by hand.
Industry volunteers in the classroom
A teacher can book a session with an industry volunteer for a particular lesson. The platform offers it to approved volunteers whose expertise fits, and whoever accepts joins the class online to talk with the teacher and students, review their ideas and mentor them through the build.
Volunteers also judge the national competition. Each judge sees entries that match their expertise and scores them on the idea, the product and the teamwork.
How it was built
The platform is a Ruby on Rails application on PostgreSQL, rendered on the server with Hotwire for the interactive parts, which keeps pages light on busy school networks. It is live with schools now.
Check-ins, student feedback and quizzes run on a questionnaire engine we built in-house. It asks one question at a time, branches on the answers, saves progress and marks answers automatically where there is a model answer. Teachers sign in with a one-time code sent by email, so there is no password to forget between terms.
Built with: Ruby on Rails, PostgreSQL, Hotwire, Kamal.
Building something people learn with?
Tell me what it does, who relies on it and what keeps you up at night about it. A few lines by email is enough. I reply within two working days.