BestHuman
•2026
Prompt Nano
A mobile Progressive Web App designed as a real-time educational companion for multi-model prompt engineering.
Built for live keynotes, this responsive Progressive Web App (PWA) delivers mobile utility where BestHuman's non-linear desktop platform is unsuited. By replacing raw text fields with toggles, radios, and voice inputs, I enabled business leaders to leverage researched, context-specific prompts in seconds. To offset high-density network interference, I optimized the codebase to load quickly over congested Wi-Fi. Operating on state-of-the-art models, the app generates high-fidelity outputs while showcasing best-in-class prompt structure.
Proof points
Outcomes and impact
Keynote companion
Designed a responsive Progressive Web App enabling room-wide audiences to scan, load, and interact with optimized prompt structures in under 60 seconds.
Zero-text composition
Replaced blank text inputs with intuitive toggles, radios, and voice inputs that dramatically reduce manual typing by activating highly researched, context-specific prompts instantly.
On-device speech parsing
Integrated a local-first speech pipeline backed by OpenAI Whisper and Google Chirp that filters out verbal noise and stutters.
The viewport dilemma
The desktop version of Prompt Studio features a non-linear canvas with a modular drag-and-drop workflow and integrated learning content, usually guided by a live instructor. Attempting to shrink this full desktop interface down onto a mobile screen was a non-starter.
Instead, I built an optimized linear workflow to capture the critical inputs in a logical flow. I replaced the open canvas with highly researched prompt presets activated by interactive toggles, radio buttons, checklists, and progressive tools; longer and more open inputs support voice input. This approach allows participants to build a top-tier prompt and receive highly valuable outputs in seconds with a few simple interactions.
Designing the live preview
To help people learn what a great prompt looks like, I built a live prompt visualizer. As users toggle presets, tap checkboxes, or input voice snippets, the live preview updates dynamically.
This visual feedback loop helps participants learn best-in-class prompt structure on the fly.
Best-in-class voice dictation
Typing long instructions on mobile virtual keyboards introduces heavy user friction. To reduce friction, I built a speech-to-text pipeline. The primary challenges were eliminating background noise and transforming rambling verbal transcripts into clean data.
Some of the technical highlights include:
- Local audio filtering: We use the Silero Voice Activity Detection neural network running locally. This essentially acts as an intelligent volume gate, instantly detecting when a person starts and stops speaking so the app only records actual speech and completely ignores background auditorium noise.
- Conversion: We convert the raw audio buffer into a compact 16-bit WAV blob, reducing data payload sizes by over 60%.
- Route to best-in-class speech-to-text models: Users can select either Google Chirp or OpenAI's Whisper.
The end result is a hands-free input system optimized to eliminate background chatter and optimize delivery to the speech-to-text models.
Designing the voice interface
To make dictation discoverable, I placed a microphone icon inside the text input fields. Tapping it opens a mobile drawer that displays the active speech-to-text status.
The interface confirms the system is working by changing states when speech is detected and rendering a live audio waveform preview. When recording stops, the participant taps the send button, which displays transmission feedback while uploading the audio buffer. Once the server processes the data, the drawer automatically closes and inserts the formatted text into the input field.
Designing for the non-happy path
Handling failures and edge cases is a hallmark of my approach to product design. Happy-path layouts often fall apart in production, so I mapped out explicit UI states for technical and hardware failures.
If a user blocks microphone access at the browser level, the drawer replaces the waveform with a clear inline notification and an explicit guide on how to reset site permissions. If the device lacks a functioning audio input, the interface gracefully falls back to standard text entry with an explanatory alert. Finally, if the connection drops mid-transmission or the speech models time out over congested conference Wi-Fi, the drawer retains the recorded text cache locally. This setup allows the participant to retry the transmission without losing their verbal input.
Engineering the wizard rail
Managing user progression through a complex multi-step flow requires an interface that scales without cluttering the screen. To solve this, I engineered a responsive wizard rail that acts as both a global progress indicator and a direct navigation tool.
Some of the technical and interaction highlights include:
- Fluid gesture navigation: The rail supports swiping, letting users manually scroll through previous or upcoming steps. As a user swipes between main screens, the highlight accent line underneath moves in sync, providing natural feedback.
- Smart overflow handling: If a workflow requires many steps, the rail scales gracefully. The system keeps the active step centered and uses masking gradients to blend overflowing text at the rail edges. Non-active tabs subtly fade and shrink based on their physical distance from the center.
- Direct navigation: Users can tap directly on any visible section title to instantly jump to that specific step, bypassing linear progression entirely.
The end result is an intuitive navigation control that looks simple on the surface but contains the robust details to keep layout transitions fast, scalable, and responsive to user touch.
The multi-model playground
To transform Prompt Nano into a true educational sandbox, we needed a way to introduce users to the rapidly evolving landscape of artificial intelligence without locking them into a single ecosystem.
We integrated a lightweight Jotai atomic state engine to drive a dynamic dispatch layer built on top of OpenRouter. This architecture allows users to configure and hot-swap the latest and greatest chat, image, and voice transcription models in real time.
By routing all generation payloads through a single configurable gateway, users can experiment with different model strengths and discover hidden gems—such as ByteDance Seed Dream for state-of-the-art image generation—teaching them the practical nuances of multi-model prompting on the fly.
Designing for the field
Live keynotes and training bootcamps present unforgiving interaction windows. Audiences scan a QR code over congested Wi-Fi, expecting immediate usability. If they encounter a learning curve or a slow page load, they drop off. The application needed to be performant, lightweight, and intuitive to use.
I optimized the codebase by auditing bundle sizes, isolating features into asynchronous chunks, and eliminating main-thread blocking time. To bypass HTTP network requests on the critical rendering path, I embedded essential brand assets as inline SVGs and engineered a script to compile a subset of the font icons containing only those actually used. These optimizations achieved a sub-second Largest Contentful Paint (LCP) and top-tier performance scores on Google Lighthouse reports and Vercel Speed Insights.
Reflections
Prompt Nano stands as a benchmark for high mobile information density and extreme micro-interaction discipline. Skinned lightly to the Best Human brand colors, the UI was designed to recede entirely. In an interactive sandbox, the chrome of the interface is never the star—the generated AI assets and the creative output are the true heroes.
By treating physical dials, progressive disclosure, and smart dictation correction as design constraints, we proved that complex utility does not require dense desktop clutter; it requires quiet aesthetics, dynamic motion feedback, and a deep respect for natural touch gestures.
High mobile utility does not require complex interfaces; it requires quiet aesthetics, high micro-interaction discipline, and a deep respect for the human touch.