Case study · Real-time tooling

Run the class, not the tech

An overlay, a control panel, and a phone remote on one live session, so the class runs itself while I coach.

Role
Concept, design & testing
Context
Self-initiated · I'm the user
Built with
Design + AI pair-building
Why I built it

Ten years coaching in person. The first time I streamed a class, I spent more time trying to work the tech than working out the class.

Live & interactive

See it running

It's all live. Tap through the phone and watch the broadcast overlay change with it.

Broadcast output · OBS
program feed · 1080p
That's real class footage running behind the overlay. It only displays; the coach never touches it directly.
Coach's remote · tap me

One session, three surfaces

Three surfaces, one shared state. Change anything on any device and it shows up everywhere at once.

Overlay
The broadcast layer

Transparent graphics over the class video: block, timer, and what's next.

Control
The desk

Build the plan and run the clock, with a live preview of the feed.

Remote
The floor

A phone to advance blocks and adjust time from across the room.

The build tool

Where the session gets shaped before going live: blocks, timing, rounds, order. Also live.

overlay control

How it actually came together

01
Getting the surfaces to actually talk

The first version barely worked. I'd start the clock on the control panel and the overlay just sat there. Getting every surface onto one shared state that updates instantly was the whole ballgame. Until that worked, nothing else mattered.

02
Editing without breaking the broadcast

I could edit exercises mid-session, but the class saw me typing it live. Now edits stay a private draft in Build mode and only go on air when I flip back to Live. The audience never sees the seams.

Live mode · on air
Goblet Squat
Now on the broadcast, seamlessly.
Live Build
flip to Live to publish
Build mode · draft
Goblet Squat
Audience still sees the old block, unchanged.
03
The remote came from chasing efficiency

Testing warm-ups, I wanted them to flow without rest timers, which meant walking back to my laptop to skip the rest after every single exercise. That back-and-forth mid-class was the moment I knew I needed a phone remote: skip, advance, and adjust the timer from wherever I'm standing.

04
The overlay as an assistant coach

Bold enough to read from across a room, quiet enough to stay out of the way. Everything holds still except the timer. It works like an assistant coach, keeping the class oriented without me repeating myself.

Where AI came in

I designed the system: the three-surface split, the shared state, what the overlay shows and how it reads. Claude turned those decisions into working code fast, so I could test the real interaction instead of clicking through static mockups.

What I'd build next

Two things I ran into that the current version doesn't handle yet.

Vertical & multi-camera

Portrait layouts for coaches who stream vertical, plus a second camera, like a phone, feeding the same system.

Audience engagement

Reactions and a lightweight chat, so the class can talk back instead of the overlay only talking one way.

The bigger picture

Right now it's built for me. But every coach, instructor, and fitness creator streaming live hits the same wall. Virtual coaching should still feel personal. Maybe I can help.