Building Feedback Panda, a SaaS for Teachers, to $60K MRR to Reclaim Time from 12-Hour ESL Shifts

The story of Feedback Panda doesn’t start in a startup incubator or through some well-rehearsed pitch—it starts with a problem at home.

Arvid Kahl’s girlfriend, Danielle Simpson, was working as an online English teacher. Like many others in that profession, she taught children in China over the internet, often with rigid lesson plans and strict performance expectations.

The work wasn’t easy. Danielle was stuck in their Berlin apartment due to injuries that made commuting impossible, and so she taught lesson after lesson for hours a day. But the teaching was only part of the workload.

After each 30-minute session, she had to write personalized feedback for the parents of every student. This feedback was not optional—it was a required part of getting paid by the platform. And since the lessons followed the same basic curriculum, the feedback ended up being largely repetitive.

What should’ve been a 6- or 8-hour workday became 10–12 hours, much of it spent retyping the same observations again and again. Arvid watched her go through this every day. Eventually, he realized the solution wasn’t asking Danielle to do less—it was building a tool that could handle the repetitive work for her.

So he did.

Using his background in software development, Arvid built the earliest version of Feedback Panda.

It was a simple tool designed to eliminate the slog of repetitive feedback writing. Teachers could store templates and reuse them for lessons that were structurally identical. It meant Danielle could go from spending hours on feedback to just minutes.

At first, it was just for her. But once Danielle began using it in her day-to-day teaching routine, the benefits became obvious. They weren’t just saving time—they were improving quality of life. The product wasn’t designed to launch. It was designed to reclaim their evenings.

Accidental Viral Launch via a Facebook Comment from Danielle

The first exposure Feedback Panda had to the outside world wasn’t planned. It came from a casual interaction in a Facebook group.

Danielle was part of several online communities for teachers. One day, a member asked how others were managing the time-consuming task of writing student feedback. Instead of explaining the entire backstory or drafting a long answer, Danielle simply posted a link to the tool Arvid had made.

That one comment changed everything.

• Within 24 hours, 80 people had signed up—completely organically.

• Arvid hadn’t even switched the Stripe payment keys from test to live mode. People were trying to pay for the product before it was technically ready to accept money.

• The demand was immediate, and it was intense. Teachers didn’t just like the tool—they needed it.

Many of these early adopters had been patching together makeshift systems using Word documents, spreadsheets, and copy-paste scripts. Feedback Panda felt like magic in comparison.

The lesson was clear: the product solved a specific, painful, widespread problem—and it was already spreading itself.

Template Cloud Turns SaaS into a Feedback Marketplace

As the user base grew, Arvid and Danielle noticed something important: the feedback teachers were writing wasn’t just similar—it was often identical. Because the lesson plans were standardized (with topics like apples, oranges, or basic pronunciation drills), most teachers were repeating the same content, lesson after lesson, student after student.

That insight led to one of the product’s most powerful features: the Feedback Panda Cloud, a collaborative library where users could upload and share feedback templates with one another.

• Users could opt into this system by checking a box to contribute their templates to the shared library.

• The sharing was entirely voluntary, but the benefits were obvious. By sharing high-quality templates, teachers helped each other reduce workload and improve the clarity of their communication with parents.

• In return, they gained access to a vast, searchable archive of pre-written feedback that could be customized to fit any situation.

This feature turned Feedback Panda from a simple SaaS into something resembling a content marketplace—though no money ever exchanged hands between users.

The shared value created a strong network effect:

• The more people who joined, the more templates were available.

• The more templates there were, the more useful the product became for new users.

• The cycle fueled organic growth, word-of-mouth referrals, and user loyalty.

Even before Arvid and Danielle added a referral system, the product was spreading rapidly inside teacher forums and Facebook groups. It was solving a real problem, in a way that felt effortless and human. That mattered.

$10 per Month Pricing and a B2B User Base That Didn’t Know It Was B2B

Feedback Panda’s pricing was deliberate. The product was positioned at $10 per month, later increased to $15 per month, which made it affordable even for freelance teachers living paycheck to paycheck. It was a price that felt like an afterthought—but delivered immense daily value.

But there was a second challenge: many users didn’t think of themselves as businesses.

Though they were independent contractors, few saw themselves as professional entities with budgets and tax considerations. Arvid and Danielle took this as an opportunity to educate their audience.

They reframed the product not as a convenience, but as a business tool—one that improved teaching quality, saved hours, and qualified as a tax-deductible expense. This repositioning helped teachers justify the cost and stick with the product long-term.

Meanwhile, support was entirely non-scalable—and entirely intentional. Arvid handled technical support himself through Intercom, often spending 30 minutes or more chatting with a single user. These weren’t just bug reports. They were relationship-building sessions. Users weren’t talking to a nameless support agent—they were talking to the person who built the product.

Those early conversations often turned new users into loyal evangelists who brought in dozens more.

5,000 Paying Customers and $60K Monthly Revenue with Just Two Founders

By the time Feedback Panda reached its peak, it had:

• 5,000 paying customers

• $60,000month in recurring revenue (roughly $700,000/year)

And it was still just Arvid and Danielle running everything. No full-time hires. No external marketing team. A few contractors helped out occasionally, but the business remained lean.

Behind the scenes, Arvid handled every technical component. That included:

• Updating and maintaining the browser extension

• Monitoring the servers and backend infrastructure

• Fixing bugs, troubleshooting data issues, and responding to support tickets

But the success came at a cost. As the customer base grew, so did the potential for disaster. A single glitch could now affect thousands of people. Every new customer was both a source of revenue and a potential support burden.

The pressure built slowly, but relentlessly. Arvid later admitted he had likely been in a state of mid-burnout without realizing it. His baseline anxiety was high, his sleep was irregular, and his calendar was always full. The product was growing, but so was the toll it was taking.

Sold to Shrewsbury Capital After Being Discovered on Indie Hackers

In late 2019, Arvid and Danielle decided to sell. Their reasons were practical:

• They wanted to de-risk their financial situation and finally have real savings.

• They recognized the “bus factor” risk—if either of them got sick, the business could collapse.

• Arvid’s burnout made it unsustainable to continue operating without a larger team.

They listed the company quietly on IndieHackers.com, linking verified revenue data from Stripe to prove consistent, linear growth.

The listing caught the attention of Kevin McArdle, who ran Shrewsbury Capital, a firm that acquires profitable software companies. Arvid and Danielle began due diligence and talked with other founders who had sold to Shrewsbury. The match felt right.

Because they had designed Feedback Panda with sellability in mind—a lesson Arvid learned from reading Built to Sell book—the transition was seamless. Documentation, automation, and processes were already in place. Handoff took just one day.

Selling the company brought immediate financial relief, reduced stress levels, and, for the first time in years, a clear calendar. It also marked the end of an intense chapter in their lives.

Affinity, Opportunity, Appreciation, and Market Size: Arvid’s Framework for Audience Selection

After the sale, Arvid turned his attention toward writing and teaching. One of the most foundational lessons he began sharing was how to choose the right audience before building anything. His framework was simple but practical—ranking audience ideas across four axes:

• Affinity – Do you actually like these people? Would you want to spend the next 5–10 years working with them?

• Opportunity – Are they underserved? Are there clear problems that no one’s solving well?

• Appreciation – Do they value tools and solutions enough to pay for them?

• Market Size – Is the niche big enough to support your business, but not so big that it attracts large competitors?

Each potential audience gets a score from 1 to 5 in each category. Arvid recommends filtering out any audience that scores low on affinity—even if they score high on budget or opportunity.

He uses the example of lawyers and notaries, who are lucrative but buried in bureaucracy. “I love you, but I don’t want to build something for you”, he says.

This framework helped him avoid one of the biggest traps in entrepreneurship: building a successful product for an audience you don’t want to serve.

Shut Up and Lurk: Why Audience Exploration Means Listening, Not Launching

One of Arvid’s strongest opinions is that most founders start talking too early. The instinct to promote, pitch, and collect feedback is understandable—but usually premature.

Instead, he advises early-stage founders to embed themselves silently in the communities they want to serve.

He calls this principle “Dwell, don’t sell.”

• Don’t pitch.

• Don’t ask for feedback.

• Don’t try to validate your idea.

Just listen.

This means observing how people talk, what frustrates them, what workarounds they use, and how they describe their problems. Arvid believes that this kind of quiet immersion is the difference between a good idea and a truly useful product.

Most founders skip this step—and pay the price. Those who don’t often find that their best ideas come not from brainstorming, but from simply being present in the right conversations at the right time.

Arvid and Danielle used these lessons unconciously and sold their business FeedbackPanda for 7-figures at $60K MRR. In hindsight, their decision to sell at the right moment turned out to be a blessing as China clamped down on online education businesses right after their sale and it had to be shut down.

Hat Tip to Tom Hunt and Indiehackers for the insights.

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