EPS Digital case study / launch readiness

RallyRei case study

Most AI tools stop at a demo. This one got launched.

RallyRei is a free AI quiz I built and run. I had it secured, made it privacy-honest and budget-honest, and published it on Google Play.

A typical demo
  • SecuredTest shortcuts left in
  • PrivateCollects whatever is easy
  • HonestFills gaps with guesses
  • PublishedLives on a dev link
RallyRei at launch
  • SecuredAudited, critical holes fixed same day
  • PrivateDaily counts only, no personal trail
  • HonestReal in-stock products only
  • PublishedLive on Google Play and the web

Left: what a demo usually has. Right: what RallyRei had before I called it launched.

Why I built it

Buying a table is full of guesswork

Enthusiasts want a table but rarely know which one, whether it fits their space, or if one table can live indoors and out. RallyRei answers that.

The question

  • "Which table should I buy?"
  • "Will it fit in my space?"
  • "Can I use the same table inside and outside?"

The quiz asks

7 questions
  • where you play
  • space
  • skill level
  • how often
  • storage
  • budget
  • priorities
highlighted: the questions that answer the worry

What they get

The right table for their space

  • A table matched to their room, use and budget
  • Indoor, outdoor or both, answered up front
  • Only real, in-stock tables, with an honest note when the budget is too low
source: the live rallyrei quiz

01 / Problem

A working demo is not a safe product

Anyone can get an AI quiz running. The hard part is trusting it with real customers.

What it is

A free quiz that recommends table tennis gear

It suggests tables, nets, balls and robots, and earns affiliate revenue through Megaspin and Amazon. I built and run it for my ESTableTennis brand.

rallyrei.establetennis.com

What it runs on

An ordinary modern stack

Nothing exotic. The work was in what surrounds it.

reactfastapimongodbvercelclaude

02 / Cost and risk

What goes wrong when a demo ships

Each gap has a price, paid in customer trust.

Exposed accounts

One forgotten shortcut can open other people's data.

Data you cannot explain

A privacy policy that is not quite true is a liability.

Confident wrong answers

A tool that invents a product costs the sale and the trust.

Stuck at a demo

If customers cannot find it, none of the work counts.

03 / What I did

Four pillars, one road to launch

I took RallyRei from prototype to published in this order.

Prototype to launch timeline July: grounding fix. August: store assets prepared. August 23: analytics live. September 22: security audit, same-day fixes and hardening, and live on Google Play. JulAugAug 23Sep 22 Grounding fixlive catalog only Store assetsicon, feature graphic Analytics livecounts start logging Audit, fixes, launchlive on Google Play Prototype to launch timeline July: grounding fix. August: store assets prepared. August 23: analytics live. September 22: security audit, same-day fixes and hardening, and live on Google Play. JulAugAug 23Sep 22 Grounding fixlive catalog only Store assetsicon, feature graphic Analytics livecounts start logging Audit, fixes, launchlive on Google Play

Timeline: July: grounding fix. August: store assets prepared. August 23: analytics live. September 22: security audit, same-day fixes and hardening, and live on Google Play.

Prototype to launch, July to September 2026.dates from my project record

Pillar 1

Security

Pillar 2

Privacy

Pillar 3

Honest answers

Pillar 4

Launch

Pillar 1 / Security

An audit found critical holes. I fixed them the same day

I ran a security audit on 2026-09-22. All three critical issues were fixed and deployed that day, and every existing session was revoked.

Critical issues fixed same day 3 / 3

All existing sessions revoked after the fix.

my security audit, 2026-09-22
Issue in plain EnglishBeforeAfter
A test login route could sign in as an existing user with no password BeforeCritical, open AfterFixed same day
Users could reach other users' data by changing an ID BeforeCritical, open AfterFixed same day
A password-reset token was exposed in a response BeforeCritical, open AfterFixed same day
Before and after for each critical issue.my security audit, 2026-09-22

Hardening, same day

  • Rate limits on sign-up, login and password reset
  • Stronger password hashing (argon2), old hashes upgraded on login
  • Google sign-in needs a verified email
  • Removed an unauthenticated admin data-wipe route
  • Generic error messages, no internals leaked
my security audit, 2026-09-22

Pillar 2 / Privacy

It counts what happens, never who did it

Analytics keep daily totals only. So the privacy policy and the Google Play Data Safety answers are simply true.

Stored: daily aggregate counts
  • Visits
  • Completed quizzes
  • Affiliate clicks
Never stored
  • User ids
  • Cookies
  • IP addresses
  • Fingerprints

Google Play Data Safety answers

App activity analytics only Shared with others no Linked to identity no Advertising ID no
how the app is built, matched to the store form

Pillar 3 / Honest answers

Only real products, at real prices

Recommendations come only from Megaspin's live in-stock catalog. It refreshes every 6 hours and is rebuilt in full every month, automatically.

The old hand-written list had drifted

Quoted price against real price for one table Old hand-written list quoted about 1,100 US dollars. The live catalog price is 2,783.99 US dollars. Bars are drawn to scale from zero. Old hand-written list about US$1,100 Real price, live catalog US$2,783.99 bars drawn to scale from US$0

One table was quoted at about US$1,100 on the old list. Its real price is US$2,783.99.

One table, two prices.my comparison of the old list with the live catalog

What else had drifted

2

tables delisted

1

table out of stock

1

price far off

my comparison of the old list with the live catalog

When the budget is too low, it says so

Shopper budget scale with the cheapest full-size table at about 650 US dollars Below about 650 US dollars RallyRei tells the shopper the budget is too low and does not invent a table. Above it, RallyRei shows real in-stock picks from the live catalog. cheapest full-size table about US$650 your budget US$0US$500US$1,000US$1,500 Below this lineRallyRei says so.No invented table. Above this lineReal in-stock picksfrom the live catalog.

Scale of shopper budgets from US$0 to US$1,500. The cheapest full-size table is about US$650. Below that, RallyRei says the budget is too low. Above it, it shows real in-stock picks.

The budget limit is deliberately soft: RallyRei tells the truth instead of making up a cheaper table.cheapest full-size table in the Megaspin catalog, approximate

Pillar 4 / Launch

Published, not parked

RallyRei has been live on Google Play since 2026-09-22, alongside the web app.

Live on Google Play

Since 2026-09-22, the same day as the security fixes.

package com.establetennis.rallyrei

Store assets prepared

Store icon and feature graphic, ready in August 2026.

App signing set up correctly

The release is signed so the store accepts updates.

04 / Human role

What I decided

AI tools helped me build it. The calls that carry risk stayed with me.

Decision 01

Ran the audit

I chose to test it before customers did.

Decision 02

Set fix priority

I decided what got fixed first.

Decision 03

Set the rule

Never invent a product. Tell the shopper when the budget does not stretch.

Decision 04

Approved the release

Nothing went live without my sign-off.

05 / Results

Launched. Usage is early

This is a readiness story, not a traction story. The numbers below are small and I am showing them as they are.

Early data: 16 completed quizzes and 2 affiliate clicks From 2026-08-23 to 2026-10-01 the event log shows 16 quiz completions and 2 affiliate clicks, 1 to Megaspin and 1 to Amazon. These are events, not unique people. Quiz completions16 Affiliate clicks2 1 Megaspin, 1 Amazon early: events, not unique people

16 quiz completions and 2 affiliate clicks (1 Megaspin, 1 Amazon), from 2026-08-23 to 2026-10-01. Events, not unique people.

Early data, 2026-08-23 to 2026-10-01.event log, counts of events not people
Registered accounts4RallyRei analytics export
RevenueNone confirmedI am not claiming any

06 / What this means for your business

Four things to demand of any AI tool

Before an AI tool faces your customers, ask for these.

Demand 01

Secured

Has someone tried to break it, and can you see what was fixed?

Demand 02

Private

Can it list what it stores in one sentence?

Demand 03

Honest

Does it answer from real data, and say so when it cannot?

Demand 04

Published and monitored

Is it live where customers are, with counts you can check?

How I measured this

Where each number comes from

  • 3 critical issues, fixed same day: my own security audit on 2026-09-22 and the fixes I deployed that day.
  • 2 delisted, 1 out of stock, about US$1,100 vs US$2,783.99: my comparison of the old hand-written list with the live Megaspin catalog.
  • About US$650: the cheapest full-size table in that catalog. It is approximate and moves with stock.
  • 6 hours and monthly: how often the live catalog refreshes and is rebuilt in full.
  • 16 completions, 2 clicks, 4 accounts: the RallyRei analytics export, 2026-08-23 to 2026-10-01. These are events, not unique people.
  • 2026-09-22 and Aug 2026: the Google Play launch date and when I prepared the store assets.
  • I make no traffic or revenue claims here. No revenue is confirmed.

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