Building for himself and growing his portfolio to $10k+/mo

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Some of the best products start as a chore the founder was tired of doing by hand.

Sergiu Chiriac is a software engineer with more than ten years of experience building web applications and SaaS products. In 2023 he started his indie hacking journey, turning side projects into real businesses. Along the way he launched multiple AI startups and learned, repeatedly, that distribution is often harder than development.

A recurring problem showed up with every launch: product discovery. Each time he shipped a new tool, he manually submitted it to dozens of startup and AI directories to gain visibility, backlinks, and early users. After repeating that process across several products, he built an internal tool to save himself the time. That tool became AI Directories.

Other founders soon asked for the same help, and it grew into a service that has now helped more than 900 founders launch and promote their startups through 100 plus curated directories. Sergiu is also building a few other products alongside it, including TransClipper, an AI powered tool that extracts and analyzes transcripts from short form videos, and BrandReply, which will help brands track and improve their visibility across AI assistants.

His revenue varies month to month, since most of his products are one time purchases rather than subscriptions, but across the portfolio he typically clears more than $10k a month. Last month was a personal record at $15.7k, with AI Directories alone contributing $9.5k of that.

Here is how the tool he built for himself became the backbone of the whole portfolio.

Sergiu started indie hacking in 2023 because he wanted to build products for himself rather than for other companies. He did not quit his job overnight. He started launching AI tools on nights and weekends, learning product development, marketing, sales, SEO, and customer support along the way.

His goal from the start was not a single company. It was a portfolio of profitable internet businesses. He built everything gradually, reinvesting the profits from one project into the next, which let him experiment, fail, learn quickly, and grow the collection over time rather than betting everything on one outcome.

The first version of AI Directories did not require a large budget, but it did require a lot of time. As a software engineer, Sergiu built everything himself, from the website and dashboard to the submission tracking system. The biggest investment was not the coding. It was researching and manually validating directories: finding startup and AI directories, checking their activity, measuring their SEO value, understanding their submission requirements, and organizing all of it into a curated database.

He funded the project entirely with revenue from his previous side projects, so no outside investment was needed. He kept expenses low by using familiar tools and leaning on AI to speed up content creation and repetitive tasks. Rather than trying to build a perfect product, he focused on solving one problem well: helping founders get listed in high quality directories without burning hours doing it manually.

Becoming his own first customer turned out to be a real advantage. Every time he launched a new product, he used AI Directories to submit it, which let him continuously improve the service based on real, lived experience rather than guesswork. He was not speculating about what founders needed. He was solving the same problems he faced himself. As more founders started using the service, their feedback shaped the product further into what it is today.

Sergiu's biggest challenge has been staying focused. As an indie hacker, new trends and ideas distract him easily, and looking back, he believes he should have spent more time improving products already making money instead of constantly starting new ones.

He has also had a few projects with cofounders that did not work out. Those experiences taught him that he works best alone: building the product, doing the marketing, and being responsible for the results himself, rather than depending on someone else's follow through.

Burnout was the third challenge, and he is direct about it. In the past he often worked more than 14 hours a day, seven days a week. Now he puts his health first. He keeps weekends for rest and sometimes takes a few hours off during the week to recharge. His summary of the lesson is simple: long term consistency matters more than working nonstop.

Sergiu builds his products on a consistent, familiar stack:

The main ongoing challenge is keeping costs under control while managing several products at once, so he regularly adjusts the stack to balance speed, simplicity, and expense. AI has become essential to his workflow well beyond product features. He leans on it for coding, debugging, writing content, and brainstorming, which lets him build considerably faster as a solo founder.

AI Directories started as a simple service: founders paid a one time fee for Sergiu to manually submit their products to more than 100 curated startup and AI directories. He charged from day one because he knew the process saved founders real hours of work while helping them gain visibility, backlinks, and early users.

As the business grew, he realized founders needed more than launch submissions. Today AI Directories has become a broader distribution platform. Founders can submit their products directly to Sergiu's own directory for $49, which includes a DR70 dofollow backlink, exposure to the community, and inclusion in the newsletter. The service also offers guest posts, sponsored placements, and other promotional opportunities to help founders reach a larger audience.

Revenue grew by expanding services rather than changing the original business model. Instead of relying on a single offering, AI Directories now runs on multiple revenue streams that complement each other, all serving the same audience of startup founders.

Sergiu's biggest growth advantage is being his own customer. When he launches a new product, he uses AI Directories for distribution and early traction. Consistently launching on startup and AI directories helps him get initial users, backlinks, and search engine visibility, and it validates both the new product and the underlying service at the same time.

Beyond directories, he shares his journey on X and Reddit: product updates, lessons learned, milestones, and genuine engagement with founders in communities where his target audience already spends time. He also runs targeted cold email outreach to introduce AI Directories to startups that could benefit from it.

Long term, SEO has been his biggest growth channel. He invests heavily in useful content, high quality backlinks, and organic search optimization across his sites. More recently he has focused on Generative Engine Optimization, improving visibility in AI powered search engines and assistants, because he believes AI search will become an increasingly important acquisition channel. That belief is the direct reason he is building BrandReply, a platform to help businesses monitor and improve how AI assistants and LLMs mention them. Organic traffic, whether from traditional search or AI powered search, has become the most sustainable source of customers across his portfolio.

His growth advice distills to one line: build your marketing engine as early as you build your product. Distribution is not something to think about after launch. It should be part of the product from day one.

Sergiu's goal is to keep building a portfolio of useful startups that solve real problems and grow his revenue year after year. Rather than relying on a single business, he genuinely enjoys building multiple products that complement each other and create long term value together.

He also wants to help other founders succeed, whether through AI Directories itself, sharing his journey publicly, or building tools that make entrepreneurship easier. Seeing others launch and grow their own businesses is part of what keeps him motivated.

If he can build products he enjoys, help other entrepreneurs along the way, and create the freedom to spend more time with his family while doing meaningful work, he will consider that a success.

You can follow along on X, where he regularly shares what he is building, lessons learned, revenue updates, and insights from his journey as an indie hacker.