Staying close to customers and hitting $16k/mo
Phuc Le was tired of building products for other people, so he started building his own. Now, SEO Utils and Ring Tonicare bringing in a total of $15.8k/mo.
Here's Phuc on how he did it. 👇
Becoming a founder
I'm a full-stack developer turned indie founder. After years of building products for others, I started building my own.
I'm currently working on SEO Utils, a desktop-first SEO app focused on speed, privacy, and one-time pricing. I'm also building Ring Tonic, a subscription call-tracking and analytics platform that helps businesses understand where their phone calls come from.
I handle most things myself, from product and engineering to support. And I focus on shipping fast and building based on real user feedback.
Currently, SEO Utils is at ~$10.4k/mo and Ring Tonic is at $5.4k MRR.
Building based on demand
I built SEO Utils because I was frustrated with how expensive and subscription-heavy most SEO tools were. I only needed a subset of features for my internal team, so I built my own tool using the DataForSEO API. It worked well and solved our problems, so I eventually decided to polish it and release it publicly.
For Ring Tonic, the motivation came directly from SEO Utils users. Many of them asked for a call tracking tool built with the same philosophy: simple, affordable, and developer-friendly. Something where they could plug in their own Twilio API key instead of paying high monthly fees. I built it based on that demand.
Shipping fast and staying independent
I started by building the minimum I needed for my own use. No roadmap, no marketing — just solving real problems. I handled everything myself: backend, frontend, data processing, and UI.
Once the core features were stable, I shared them with some SEO groups on Facebook, listened closely to feedback, and iterated quickly. The product grew from real usage rather than assumptions, which helped keep it focused and practical.
Choosing a stack I know well has been a big advantage. It lets me ship fast, fix issues quickly, and stay fully in control as a solo founder.
Here's my stack for SEO Utils:
Go
Vue
TailwindCSS
Wails
Python
And for Ring Tonic:
Laravel
InertiaJS
TailwindCSS
Vue
Build in public sooner
Building in public and staying close to users has been my biggest advantage.
I focus on Facebook groups, X, LinkedIn, and email lists from some free tools I built and shared with SEO communities.
The frequent updates and clear changelogs in my Facebook group, for example, have built trust and kept users engaged. And the direct feedback that I receive there and on my other socials has helped me prioritize the right features.
Most of all, though, it drives word of mouth, which is my biggest driver of growth. Over time, happy users recommended the product to others.
If I were starting over, I would build my audiences first, talk to users sooner, and invest in marketing much earlier instead of assuming a good product would sell itself. I'd still build the same way, but I'd share the journey sooner and more publicly.
Scratch itches and focus on small improvements
Here's my advice:
Start small and build something useful, even if it’s not fancy. Solve a real problem you personally have, or build a feature you wish an existing product had. That’s how both SEO Utils and Ring Tonic started.
Talk to users as much as possible until you truly understand what they need from your app. Build features based on real user problems, not just what you feel like building. Once you understand your niche and your competitors, you will have a much clearer direction for your product.
If competitors already have a feature, don’t be afraid to build it too, but focus on better UI/UX and small details. Minor improvements in workflow can save users a lot of time and make a huge difference in how valuable your product feels.
Leave a Comment
16k a month ist crazy
Love the “build what you need first” approach.
Starting with internal tools removes so much guesswork — you already know the pain is real.
Also interesting how Ring Tonic came directly from SEO Utils users. That kind of adjacent product expansion feels way less risky than chasing random ideas.
At what point did you know SEO Utils had real product-market fit versus just early adopter enthusiasm?
This is exactly the kind of story I needed to read today. I'm building StayActive a desktop utility for remote workers (anti-idle / keep-alive tool) and the "Desktop-first" approach you describe really resonates.
How did you find your first paying customers? Was it purely organic from IH, or did you actively reach out to communities?
Really liked the emphasis on small, demand-driven improvements.
When you say you stayed close to customers, was that mostly reactive (support conversations) or did you have a more structured way of reaching out regularly?
I’ve noticed it’s easy to say “talk to users,” but harder to build a consistent loop around it.
I'm also a full-stack developer turned indie founder. Like you, I started building my own product. Sure our tech stacks are different (Rails/React instead of Go/Laravel), but the shift in mindset I'm sure is the same. I also chose to build the product I needed for my own use, handling everything myself, bootstrapping everything so far to stay independent.
I've also been entirely heads-down for 18 months and kept telling myself I'd share the journey once things were perfect. Maybe that was just an excuse. Reading this made it clear I've been wrong to wait.
Ring Tonic is also a great example of what staying close to customers actually looks like in practice. A whole second product born directly from listening to your existing users. That's not something you can plan for; it just happens when you're paying attention.
Those are impressive numbers for a solo founder.
Hi man, congrats! Apart from the "build in public" strategy, did you use other marketing/distribution techniques ? Ex UGC, Ads
same here for me, I'm also building something cool and really feel need of a mentor.
I'm interested to know any marketing/distribution techniques as well.
Congrats on $15.8k MRR! The Ring Tonic origin story (users asking → building) is exactly right.
Curious on your "continue shipping" plan: When deciding what to build next for SEO Utils or Ring Tonic, how do you validate a feature is worth the engineering time before coding?
I learned the hard way that "users asking" ≠ "users paying." Built something once that everyone said they wanted, $20K, 3 months, 0 sales. Now I test with video prototypes first — validate demand before the MVP.
Would love to hear your take on pre-build validation vs. shipping fast and iterating.
The part about building for others vs building your own thing really hit me.
I been building apps for clients from 7 years now. 100+ apps delivered. Every time I build something great for a client I think same thing — why am I not building this for myself.
Your one time pricing idea for SEO Utils is very smart. Most founders I work with are tired of subscription fatigue. They will pay good money for something that just works without monthly bill.
One thing curious me — Facebook groups worked better than X or LinkedIn for you? We always assume LinkedIn is best for B2B but sounds like you found different answer.
Asking because we also trying to figure out best channel for our agency right now 😄
Super solid journey — especially building from your own pain first and then expanding based on real user demand.
Going from internal tool → $10k+/mo product is no joke. And the fact that Ring Tonic came directly from user requests shows you’re actually listening, not guessing.
Also love the “scratch your own itch + small UX improvements” angle. That’s where indie founders quietly win.
Really cool to see Ring Tonic in here — I'm building in a related space (AI voice agents for service businesses that answer missed calls and capture leads). The phone call vertical is so underserved by tech.
The part about "build in public sooner" hits hard. I spent months heads-down building and barely talking to anyone. The moment I started cold calling potential customers instead of cold emailing them, I learned more in a week than I did in 3 months of building alone.
Also love the "scratch your own itch" philosophy. I noticed service business owners losing customers to missed calls and realized nobody was solving it well. Voicemail is broken — 80% of callers just hang up. That became the whole thesis.
Question for Phuc: with Ring Tonic being call-tracking focused, have you seen demand from customers who also want the actual call answering handled (not just tracked)? Curious if that's a feature request you've gotten.
Biggest takeaway: hanging out in FB groups/X/LinkedIn and shipping what users literally ask for > any growth hack.
Rooting for 20k+ soon — keep it up! 🙌
Interesting story. Did building in public ever become a distraction, or did it mostly help you stay focused on the right problems?