FillFast

About

FillFast fills any form with realistic, coherent fake data — in a single click.

Outcome

I designed and built the entire product myself — positioning, UI/UX, the extension, and the landing page — building in public along the way. FillFast is now part of my own daily development and testing workflow, and is expanding to the wider dev/QA community.

Problem

Devs and QA fill the same forms dozens of times a day: account sign-ups, orders, customer records. Hastily typed data like "asdf@test.com" pollutes demo environments, makes bugs harder to reproduce, and makes demo screens look unprofessional.

The problem isn't typing speed — it's that test data lacks coherence.

Research

Watching testing workflows across the product teams I've worked with, three patterns kept repeating:

• Everyone invents their own test data; nobody can reuse anyone else's.
• Existing autofill tools generate disconnected values — name, email, and phone never add up to one plausible person.
• Vietnamese data (full names, addresses, valid phone prefixes) is barely supported by any tool.

Product System

FillFast is built around the idea of a coherent record: every fill produces one complete "person" — name, email, phone, and address that agree with each other and are valid per locale.

• The extension detects fields semantically (label, name, placeholder) instead of hard-coding selectors.
• A locale-aware data generator, with first-class Vietnamese support.
• Records can be pinned and reused to reproduce an exact test scenario.

Role

• Product positioning and build-in-public strategy
• UI/UX design for the extension popup and landing page
• Full extension development (TypeScript)
• Operations, releases, and user feedback loops

Learnings

Small product, sharp scope

An extension that solves exactly one daily pain is far easier to polish and to explain than a platform that "does everything".

Building in public is a feedback loop

Sharing progress publicly forces me to ship consistently and hear feedback early — before investing deeply in features nobody needs.

Eat your own cooking

Using FillFast every day in my own work is the most honest QA there is — every rough edge shows up immediately.