# Mockingly.AI

Aiolum story: https://aiolum.com/story/mockingly-ai/ · added 2026-11-03 · updated 2026-11-03

**In short.** Mockingly.AI (AI mock interviewer for system design interviews, Netherlands): US$294 a month MRR, November 2026. Evidence grade A: disclosed by a company or a filing, or verified by a payment processor. Team: 1 founder; the operating company is a Dutch sole proprietorship. Launched August 2025; still running, revenue falling.

AI mock interviewer for system design interviews · Netherlands · AI-native · solo founder · still running, revenue falling · group: Learning and study

- Outcome: US$294 a month MRR, November 2026 (evidence grade of the headline number: A; headline in US dollars: 3528)
- Launch: August 2025; months from launch to the outcome: 15
- Team: 1 founder; the operating company is a Dutch sole proprietorship
- Outside funding: None reported
- Main factor: Niche
- Meters, 1 to 4: evidence strength 3, copyable pattern 3, capital needed 1
- Tags: AI-native, Solo founder, Bootstrapped, Running, B2C, Education

Links:

- Visit mockingly.ai: https://www.mockingly.ai/
- Verified revenue on TrustMRR: https://trustmrr.com/startup/mockingly-ai

**The product.** A practice tool for the system design round of software engineering job interviews. The user picks a question, draws the architecture on an online whiteboard, and an AI interviewer asks follow-up questions about scaling, databases and failure cases. After the session the paid plan gives a written analysis and a readiness score.

**Why it worked.** System design interviews are hard to practise alone, because the value is in the follow-up questions that a senior engineer asks about your design. A language model that can read the diagram and the chat can ask those questions at any hour. The free plan gives unlimited practice, and the Pro plan at US$14 a month sells the analysis, the score and company-specific questions.

Evidence grades: A = disclosed by a public company, a filing or a payment processor, or verified by one; B = two or more independent reports agree, or a journalist confirmed it; C = a founder claim that no one else verified; D = reported, not verified: one founder claim or a third-party estimate with no second source; calc = computed on this page from graded facts.

## Summary

Mockingly.AI is an AI mock interviewer, a program that plays the role of the interviewer in a practice interview, for the system design interview, the job interview round in which a software engineer designs a large system (for example a chat service or a rate limiter) on a whiteboard and defends the choices. The user draws boxes such as load balancer, API gateway and database on an interactive canvas and explains the design in a chat; the AI, which the privacy policy names as OpenAI's GPT-4o, reads both and asks follow-up questions. The terms of service call it "an educational and practice tool".

TrustMRR lists Ayusch Jain as the founder and gives 8 August 2025 as the founded date. The site is run by Appsy Studio, a eenmanszaak, the Dutch legal form for a business owned by one person, registered with the Dutch Chamber of Commerce (KVK). TrustMRR reads the business's Stripe account through an API key and showed on 3 November 2026 a monthly recurring revenue (MRR, the subscription income expected each month) of US$294 from 21 active subscriptions, and US$4,018 in revenue since the start. The best month was May 2026 with US$406; October 2026 brought US$294.

The revenue is small but it is verified by the payment processor, grade A. This page shows how one engineer built a narrow paid tool on top of a language model, why the figure fell in October 2026, and what happened to earlier companies that sold interview and career preparation to engineers.

## Pricing

Mockingly.AI prices on 3 November 2026, from the home page and the terms of service (grade C)

| Plan | Per month, billed yearly (US$) | Per month, billed monthly (US$) | Limit |
|---|---|---|---|
| Free | 0 | 0 | unlimited AI interview practice and whiteboard; no detailed analysis, no readiness score, no company-specific questions |
| Pro |  | 14 | detailed analysis, readiness score and trends, company-specific and previously asked questions, trivia quizzes, priority email support |

The /pricing link loads its content by script and returned no prices; the plans below are printed on the home page. The terms of service say the Pro plan is billed monthly through Stripe, with no yearly option, and that no VAT is charged because the owner uses the Dutch small-business scheme (KOR).

## How much revenue does Mockingly.AI make? The numbers, graded

A one-person AI interview-practice site with US$294 a month in Stripe-verified recurring revenue and US$4,018 in total by 3 November 2026

| Fact | Value | Grade | Note | Sources |
|---|---|---|---|---|
| Monthly recurring revenue, 3 November 2026 | US$294 | A | TrustMRR, read from Stripe through an API key, revenue last synced 3 November 2026. The profile also shows -25.0% MRR growth over the last 30 days. | [1] |
| Active subscriptions, 3 November 2026 | 21 | A | TrustMRR metric snapshot. | [1] |
| Subscriptions times the Pro price | 21 × US$14 = US$294 | calc | Calculated: matches the MRR exactly, so every subscriber appears to pay the single US$14 monthly plan. | [1, 3] |
| Annual run rate | US$3,528 a year | calc | Calculated: US$294 × 12. This is the headline figure in outcomeUsd. | [1] |
| Total revenue since the start, 3 November 2026 | US$4,018 | A | TrustMRR, all time. The copy of 31 October 2026 showed US$3,990. | [1, 2] |
| Revenue in the 12 months to October 2026 | US$3,836 | A | TrustMRR copy of 31 October 2026. The sum of the twelve monthly values from November 2025 to October 2026 is also US$3,836. | [2] |
| Revenue before November 2025 | about US$154 | calc | Calculated: US$4,018 all time minus US$3,836 for November 2025 to October 2026 minus US$28 in November 2026. | [1, 2] |
| Best month | US$406, May 2026 | A | TrustMRR monthly timeline. | [1] |
| October 2026 revenue | US$294 | A | TrustMRR monthly timeline. September 2026 was US$392. | [1] |
| Fall from the best recent months | 25% below September 2026, 28% below May 2026 | calc | Calculated: (392 − 294) / 392 and (406 − 294) / 406. | [1] |
| Profit margin, last 30 days | 95.0% | A | TrustMRR snapshot. TrustMRR does not say which costs the margin includes. | [1] |
| Founder | Ayusch Jain | C | TrustMRR founder listing. He is also the named author of some of the site's guides, for example the RAG guide of 8 September 2026. | [1, 7] |
| Legal form | Appsy Studio, eenmanszaak (sole proprietorship), Netherlands, KVK 97901946 | C | About page and terms of service. A sole proprietorship has one owner. | [4, 5] |
| Founded date | 8 August 2025 | C | Founder-provided field on TrustMRR. | [1] |
| AI model | OpenAI GPT-4o, paid API tier | C | Privacy policy: "All interview questions, feedback, and analysis are generated by AI models (specifically, OpenAI's GPT-4o)." | [6] |
| Guides on the blog | 27 posts, the first dated 1 October 2025 | C | Blog index, read 3 November 2026. Most are signed "Mockingly"; some by Ayusch Jain. | [7] |
| Outside funding | none reported | C | No source names an investor or a round. TrustMRR lists none. | [1] |
| Time from founded date to the headline figure | 15 months | calc | Calculated: August 2025 to November 2026. | [1] |

How to read this table: a grade A value was read by TrustMRR from the company's Stripe account. A grade C value is founder-written text on TrustMRR or the company's own pages. A "calc" value (grade X) was computed on this page from the rows above it.

## When did Mockingly.AI launch, and how did it grow? Timeline

From a founded date in August 2025 to 21 paying subscribers fifteen months later. Each entry carries its grade.

- **8 August 2025** (grade C [1]): Founded date that the founder gave on TrustMRR.
- **August to October 2025** (grade calc [1, 2]): First payments: about US$154 in total before November 2025.
- **1 October 2025** (grade C [7]): The first guide appears on the blog, the start of a library of system design interview guides that are free to read.
- **November 2025** (grade A [1]): US$168 in verified revenue.
- **December 2025** (grade A [1]): US$294 in the month.
- **May 2026** (grade A [1]): Best month so far: US$406.
- **June to September 2026** (grade A [1, 7]): Revenue holds between US$364 and US$392 a month. Guides on machine learning, LLM gateway and RAG system design are added.
- **October 2026** (grade A [2]): Revenue falls to US$294; no payments from 27 to 31 October.
- **3 November 2026** (grade A [1]): MRR US$294 from 21 active subscriptions; US$4,018 since the start.

## Why did Mockingly.AI work?

### A narrow niche with a clear buyer

The product does one thing: the system design round for software engineers, with backend, Android and machine learning questions. The buyer is an engineer with an interview coming, who already knows what the round is and why practice helps.

### The language model is the interviewer

The expensive part of a mock interview is a senior engineer's time. Here GPT-4o reads the diagram and the chat and asks the follow-up questions, so one person can sell interviews at any hour without hiring interviewers.

### Free practice, paid feedback

The free plan gives unlimited practice sessions. The paid plan, at the price of US$14 a month that the home page lists, sells what comes after the session: the analysis, a readiness score with trends, and company-tagged questions.

### Guides as the front door

Twenty-seven long guides, free to read with no account, cover common questions such as rate limiters, RAG systems and offline sync. No source states how customers arrive, so this page records the channel as unknown.

## How it was built

These details come from the company's privacy policy, terms of service and the founder-written TrustMRR profile. They are grade C.

- Next.js frontend hosted on Vercel, with Vercel Analytics for cookieless page counts.
- Supabase for the database and authentication, with row-level security policies; users sign in with Google OAuth.
- OpenAI's GPT-4o through the paid API tier generates the interview questions, feedback and analysis; drawings and messages are sent to OpenAI.
- Stripe for subscriptions, billed monthly; PostHog for product analytics after cookie consent.
- Run as a one-person Dutch sole proprietorship under the KOR small-business scheme, so no VAT is charged.

Sources: [1, 5, 6]

## Who tried this before Mockingly.AI, and why did they fail?

Four companies in our database of failed startups sold learning or career preparation to people who wanted a better job, three of them to future or current software engineers. The values below are from that database and are not independently verified.

The failed startups come from our database of dead startups, retold here in our own words; Its entries are AI-assisted summaries of public sources, so they carry no evidence grade.

### Dev Bootcamp (2012 to 2017; funding US$30M; cause: Competition)

- Promise: A 19-week in-person course that turned beginners into hireable developers.
- Why it died: Many cheaper copies undercut its price, and employers stopped trusting bootcamp graduates.
- Record: 

### The Iron Yard (2013 to 2017; funding US$15M; cause: Ran Out of Cash)

- Promise: Job-ready developers in 12 weeks, without a computer science degree.
- Why it died: It opened 15 campuses before one was proven, and enrollment fell as bootcamps became common.
- Record: 

### Pesto (2020 to 2024; funding US$5M; cause: Unit Economics)

- Promise: Training for software engineers in emerging markets, paid back from the remote jobs they would get.
- Why it died: High default rates and expensive customer acquisition made each student a loss.
- Record: 

### Tutorspree (2011 to 2015; funding US$1.9M; cause: No Market Need)

- Promise: A marketplace to find a good private tutor online.
- Why it died: It never matched enough tutors and students in one place, and depended on human tutors for every session.
- Record: 

## What changed

The four predecessors all depended on human teachers or on campuses: instructors, tutors, and buildings. Their costs rose with every student, so they needed venture money and large volume before they could make a profit, and they failed when price competition or slow demand arrived.

Mockingly.AI replaces the human interviewer with a language model that it rents by the request. The fixed cost is one person's time, the hosting and the model calls, and TrustMRR reports a 95% profit margin over the last 30 days. That lets a business with 21 subscribers exist at all. What has not changed is the problem of demand: interview preparation is bought for a few weeks and then cancelled, and the October 2026 fall shows how quickly a small subscriber base moves.

## Can one person copy Mockingly.AI now?

**Verdict: Yes, and it is a small, honest example of the method.**

Nothing here needed capital or a team: a Next.js site, Supabase, Stripe and the OpenAI API. The difficulty is the size of the result. After fifteen months the verified revenue is under US$400 a month, so this is a template for building and charging, not yet for growing.

1. Pick one interview round or exam where the value is in follow-up questions, and make the AI ask them.
2. Give unlimited practice for free and charge for the feedback after the session.
3. Write long, free guides for the common questions so that people searching for them find the site.
4. Connect the payment processor to a public revenue page so that the figures can be checked.

**What is still open.** Other interview rounds and professional exams with a spoken or drawn part: product management cases, data engineering, behavioural interviews, architecture reviews, and the same rounds in other languages.

## What could go wrong for Mockingly.AI?

- **Small and falling revenue.** US$294 a month is a side income, not a salary. October 2026 was 25% below September and 28% below May 2026, and TrustMRR shows MRR growth of -25.0% over the last 30 days, with no payments from 27 to 31 October.
- **Short customer life.** People buy interview practice for an interview and cancel after it. The 21 subscriptions must be replaced all the time, and no source gives the churn rate.
- **One model provider.** The privacy policy names OpenAI's GPT-4o as the only AI model. A price change, a model retirement or an outage at OpenAI reaches the product directly.
- **"Previously asked questions" are not verified.** The home page says the questions are "the exact system design problems recently asked at Google, Meta, and Amazon" and the Pro plan sells "All previously asked questions & solutions". No source shows where the question list comes from, and this page does not repeat the claim as a fact. The site shows no testimonials and no user counts.
- **Practice only.** The terms of service describe simulated interviews "for educational and practice purposes" and say the product is "not a professional hiring assessment". Nothing on the pages read offers help during a real interview.

## Sources

1. TrustMRR profile of Mockingly.AI, Stripe-verified metrics, revenue last synced 3 November 2026 — https://trustmrr.com/startup/mockingly-ai.md (grade A). Read the markdown profile, downloaded live on 3 November 2026. The revenue, MRR, subscription and margin figures are read by TrustMRR from the company's Stripe account through an API key; the profile text (founder, founded date, description, tech stack) is founder-written and graded C.
2. TrustMRR profile of Mockingly.AI, earlier copy, revenue last synced 31 October 2026 — https://trustmrr.com/startup/mockingly-ai.md (grade A). Read the markdown profile, a copy downloaded on 31 October 2026. Source for the 12-month total and the October 2026 daily values.
3. mockingly.ai home page: Practice System Design Interviews Online with AI — https://www.mockingly.ai/ (grade C). Read in full, downloaded 3 November 2026. Source for the product description, the four steps and the Free and Pro plans.
4. About Mockingly — https://www.mockingly.ai/about (grade C). Read in full. Source for the sessions, the question bank and the operating company.
5. mockingly.ai Terms of Service — https://www.mockingly.ai/terms-of-service (grade C). Read in full. Source for the legal form, the practice-only purpose, the minimum age of 16, monthly billing and the KOR VAT note.
6. mockingly.ai Privacy Policy — https://www.mockingly.ai/privacy-policy (grade C). Read in full. Source for the AI model (GPT-4o) and the processors Supabase, OpenAI, Stripe, Vercel and PostHog.
7. System Design Interview Blog, Mockingly — https://www.mockingly.ai/blog (grade C). Read the index of 27 posts with their dates and authors.
8. Database of failed startups, local export — /method/#dead (grade C). Local export. AI-written summaries, not independently verified. Source for the failed predecessors.