Solopreneur case studies — 7/9
Solopreneur and side-business cases
145–168 of 201
¥50,000 a Month, Five Years After the First Release. An Indie App's "Quietly Effective Tactics" — and the Ones That Didn't Work
A case of an indie-developed app reaching ¥50,000 a month — five years after the first release, about two years after monetization began. Funnel improvements and the Apple Small Business Program worked; defaulting to the annual plan and A/B testing did not. The record discloses which tactics succeeded and which failed.
¥748,000 in 30 Days and a Category No. 1 on Coconala. The Listing Strategy of "Niching Down a Commonplace Service"
A hands-on record of earning ¥747,800 in 30 days (Feb–Mar 2022) and reaching No. 1 in the affiliate category on Coconala. The core: improving three things — sales copywriting, profile, and thumbnail — plus a strategy of "taking a commonplace service and listing a niched-down version of it."
BuiltWith: One Person, $14M a Year (Later Estimated at $22M+) — the True Nature of a 19-Year “Just Look It Up” Service
BuiltWith, which tells you "what technology this website is built with," was started by Australia's Gary Brewer in 2007 and is widely reported to have reached over $14M (about 2.1 billion yen) in annual revenue with effectively one person. Acquisition is 100% organic at 2 million pageviews a month. A record that raised the ceiling on what a one-person business can earn.
Starting a takoyaki food truck cost 2.82–4.39 million yen — a working owner's full line-item breakdown
A takoyaki food-truck owner in Gifu publishes his startup costs item by item: a total of 2.82–4.39 million yen, or 3.8–5.4 million yen once 1 million yen of working capital is added. Vehicle-related costs make up about 70% of the total, splitting expenses into ones that can be trimmed and ones that can't.
10 hours at the day job plus 3 hours commuting, and still ¥94,000/month from a Python automation side business — why he walked away after ¥150,000 total
A systems engineer, six months into his job, narrowed his side hustle to Python + Selenium business automation. His October 2022 orders totaled ¥94,380 — ¥51,480 via Lancers plus ¥42,900 via CrowdWorks. But he walked away after earning ¥150,000 total, and even disclosed why.
CLOUD PAPER: Shingo Irie’s Other Sale — an Estimate/Invoice SaaS Sold via M&A Two Months After the MENTA Transfer
After transferring MENTA to Lancers, Shingo Irie also sold his cloud estimate and invoicing service "CLOUD PAPER" via M&A in December 2020 (price undisclosed). A rare Japanese record of a single indie developer executing two exits in the same year.
Stoic Muse: 100–150 Stoic-Philosophy T-Shirts a Month at 40% Margin — What Actually Worked Was 200 Five-Star Reviews
After burning out on Amazon FBA, an individual reopened a dormant Etsy store in February 2020. Stoic-philosophy print-on-demand T-shirts now sell 100–150 units/month at $3,000/month with 40% margin. Facebook ads broke even; what drove growth was Etsy SEO and 200 five-star reviews.
Bannerbear: 8 Months at $0, 7 Failures, 2 Pivots — the Complete Record of Reaching $10K MRR
Jon Yongfook's image-generation API Bannerbear reached $10,455 MRR in January 2021 — after 7 failed products in a 12-startups-in-12-months challenge, Previewmojo plateauing at $400, and an API pivot that churned existing customers. He has published the numbers and tactics of every phase.
Living Cozy: After Six Failed SaaS Startups, a 350K-Monthly-Visitor Home-Decor Comparison Site Sold for Six Figures in Three Years
Ash Read failed at six software companies, then built the home-decor comparison site Living Cozy on weekends using Webflow, grew it to 350K monthly pageviews and an 80% margin, and sold it via Flippa for six figures in 2023. The turning point was giving up on being "a builder" and leaning into his 10 years of skill instead.
STARBAR Okinawa: Selling a Thriving Bar to Fund a Shabu-Shabu Chain — a “Strategic Fundraising” M&A
STARBAR, an upscale bar in Okinawa City serving U.S. military-affiliated customers, was transferred to Aichi-based trading company Pembroke while still a thriving business with healthy finances and high margins. The goal was not retreat but securing funds for multi-store expansion of a new shabu-shabu concept — a real example of "sell the profitable store and bet on the next one" as strategic fundraising.
Avatar AI Made $150K in a Week — So Why Did Levels Shut It Down Himself? A Record of Walking Away from a Winning Hand
Pieter Levels's Avatar AI rode the early AI-avatar boom to roughly $150K in one week — the fastest money he had ever made. Yet instead of chasing the boom, he called it "too cheap — I want to solve real problems" and pivoted to the utility-focused PhotoAI. A rare record of quitting in the middle of success.
A Side-Business Smartphone Lens Filter Brand Sold in Two Months After Listing, Prompted by a Job Change. The Conditions for a "Perfect-Score Sale"
THE emo, a smartphone camera lens filter brand Renpei Taniguchi launched as a side business in 2020, grew by winning fans through crowdfunding and social media. Facing a job-change deadline, he listed on multiple platforms, met with 4 companies, and transferred the business to Mediair Inc. in under two months. His own verdict: "a perfect score."
Podseeker: 10 Inquiries in Week One, Then Six Months of Silence — How a Price Cut Closed a Six-Figure Sale
The podcast contact database "Podseeker" reached $1,000 MRR within months at $50/month. Right after listing on Acquire.com, it drew 10 inquiries in a week, then stalled for 6 months at a high asking price, before closing at a six-figure dollar sum after a price cut.
Four Years of Stock Photography, ¥185,000 Total. A Real Record of the "¥4,000 a Month" Median
A four-year account of selling stock photos (Adobe Stock, Photo AC, PIXTA). Cumulative sales came to roughly ¥185,000 — about ¥4,000 a month on average. Even left nearly untouched, the money keeps trickling in at the level of "one night out per month." Data that sits at the opposite pole of glamorous success stories, close to the median for entrants.
Even Air HR, a Small HR Tool with $40K in Annual Revenue, Found a Buyer — the Market Where the "Smallest SaaS" Still Sells
Air HR, a small HR software business with $40K (about ¥6M) in annual revenue, was sold to payroll SaaS company KarbonPay. Even a SaaS at roughly ¥500,000 in monthly revenue can attract a strategic buyer — a case showing that the "too small to sell" line sits far lower than people imagine.
Side-Business Blog "Tsuzuki Blog": From ¥42,000 to ¥1 Million a Month in One Year. Breaking Down the Published Monthly Data
Tsuzuki Blog began in earnest in January 2019 while its author handled SEO at an IT company. Month six: ¥69,000 in revenue (¥17,000 AdSense + ¥52,000 affiliate) on about 21,000 pageviews. Revenue concentrated in 2–3 VOD articles, reaching ¥1 million a month roughly one year in. We break down the published monthly data.
Carrd: $2M ARR With Zero Marketing Spend and an Anonymous Solo Developer — the “Don’t Add Features” Strategy
Carrd, the one-page-only site builder, is run single-handedly by an anonymous developer known as AJ, reaching $1M ARR five years after launch and later $2M ARR, with 3.3 million sites and 2.2 million users. Marketing spend was zero — growth came from the audience built with his previous project, the free template site html5up.
Peing: Built in 6 Hours, 200M Monthly PV in One Month — Sold at the Breaking Point of Virality
Peing, an anonymous Q&A service built in 6 hours by 26-year-old indie developer Seseri, hit 400,000 daily PV on day 5 and a 200M monthly PV pace within a month. Overwhelmed by server load and the limits of solo operation, it was sold to Jiraffe just one month after launch (price undisclosed).
Shift: From $80 in Week One to $50,000 MRR in 10 Years — a Laravel Auto-Upgrade Tool Run on $100/Month
Shift, which automates Laravel version upgrades, launched in 2015 with just $80 in its first week. Ten years later, it has processed over 175,000 runs and reached $50,000 MRR — zero employees, monthly operating cost of about $100. The turning point was customers telling him he was charging too little.
PhotoAI at $132K a Month, Zero Employees, 37,000 Commits a Year: Dissecting Pieter Levels' "Solo-Run" Playbook
AI photo generator PhotoAI earns $132K a month (about ¥19.8M), and Pieter Levels' entire portfolio tops $228K a month—run with zero employees. 37,000 commits a year, two-second deploys, GPT-4-automated moderation. Levels openly admits only 4 of his 70 projects hit. Here's what's actually behind his operation.
¥4.61 Million a Year, Five Years After Starting to Learn Programming. The Full Three-Year P&L and Playbook of an Indie Education App
An education web/smartphone app that began as a homemade tool to ease cram-school work grew from ¥120,000 (FY2023) to ¥1.47 million (FY2024) to ¥4.61 million in revenue (¥3.91 million profit) in FY2025. The developer discloses what drove each year's growth. Fully independent as of March 2025.
TypingMind: Quit at $600 MRR, Then $45K/Month — Every Decision in Tony Dinh’s Build-Sell-Release Loop
Vietnamese indie developer Tony Dinh quit his job at $600 MRR. TypingMind, shipped right after the ChatGPT API opened, made $1,000 on day one, $10,000 in 10 days, and later $45K/month. Meanwhile, when the Twitter API crisis hit Black Magic, he decided within two weeks to sell it for $128K. Every offensive and defensive call is public.
Month One Paid ¥400 an Hour: Four Months of Fully Disclosed Kitchen Car Sales — and the Fifth Month, When COVID Stopped Everything
Real month-by-month data from a kitchen car's first 4 months. Month one: 8 days of vending, ¥64,000 in sales and ¥28,000 in profit (about ¥400/hour by the owner's reckoning). By month four: ¥384,000 in sales, ¥334,000 in profit. Best single day: ¥50,000. Then, in month five, COVID erased the vending venues — rare public data capturing both the ramp-up and the fragility.
Zenn: A Solo-Built Dev Community Transferred to Classmethod 4.5 Months After Launch
Nine days after launch, the solo-built Zenn published "Zenn needs help," fielded offers from more than 20 companies, and was transferred to Classmethod 4.5 months after going live. The decision-making process of a case where "growth was too fast for one person to handle" is fully public.