Building My Own SaaS: LaizyNote

Joshua Maurer

Web Developer & Freelancer

July 19, 2026

16 months, several hundred hours alongside client work, one finished product: LaizyNote is a business operating system for freelancers and solo entrepreneurs – notes, tasks, projects, time tracking, contacts, calendar, documents and an AI assistant in a single interface.

The other articles here are about client projects. This one is different: LaizyNote is my own product. That changes everything – the perspective, the responsibility, and the honest realization of how much a "finished" SaaS really takes.

I'll show you why I built it, how you keep an overview at this scale, what it means to build AI into a product – and why the last 10 % took longer than the first 90 %. No code, but honest.

Why build your own SaaS?

Out of my own need. It bugged me that there was no tool you could start with for free, that had everything I needed – and that would later also help me run my business. The big names can do a lot, but they're bloated: you spend weeks setting up before you jot down your first thought.

I wanted the opposite: start instantly, yet have everything on board when you need it. While building, it became clear that this isn't a niche but a gap. Freelancers and solo entrepreneurs juggle five tools – notes here, time tracking there, invoices somewhere else – and none of them shows how their business is actually doing.

What's inside?

LaizyNote bundles the tools a self-employed person needs every day into one connected workspace – in the browser and as an installable app (PWA) on phone and desktop, offline-capable.

That sounds like a lot – and that was exactly the real challenge. Not a single feature, but the interplay: a time entry belongs to a task, which belongs to a project, assigned to a client, who lives in a workspace that several people can share. Keeping these relationships clean and secure is half the battle.

Business Insights: the numbers that show your business

If I had to highlight one feature, it's this one. Everything else exists elsewhere too. But Business Insights shows you what you, as a self-employed person, actually need to know – and what no tool presents properly.

Because LaizyNote already knows your time, projects, clients and revenue, it can derive the metrics you'd otherwise maintain in a spreadsheet:

• Your real hourly rate – not the one you bill, but the one left over after everything
• The trend over years: is your business really growing, or does it just feel that way?
• Client health – which clients carry you, which cost more energy than they bring in
• Revenue distribution, open invoices, and whether your portfolio leans too heavily on one client

Deep dive 1: keeping an overview at this scale

The biggest technical challenge wasn't a single hard feature. It was keeping an overview: where which data lives, where it flows, who is allowed to see what – and how you make sure it stays that way while ten other things change.

LaizyNote runs on Firebase. The data lives in Firestore, the logic in server-side Cloud Functions, all hosted in the EU. Every user has a personal space but can also share team workspaces with others – with roles and permissions. And that's exactly where it gets tricky: every single query has to know whether it concerns personal or shared team data, and whether the user may access it at all.

To keep this from turning into chaos, everything follows the same patterns: consistent data paths, workspace-specific caches, centrally defined rules instead of special cases per feature. It sounds bureaucratic, but it's the only way a new feature doesn't break three old ones. Automated tests watch over the critical paths – especially the security rules and billing.

Why the last 10 % takes months

Prototyping is incredibly fast today. A new module stands in days. What really eats time is the polish – the last 10 % that separates a hobby project from a product people trust with their work.

That 10 % is made of things nobody notices as long as they work, and that stand out immediately when they don't:

• What happens with empty data, on the first login, with 10,000 entries?
• A link that should open the right plan straight after sign-up – and quietly fails if a single parameter is missing
• A bonus offer that accidentally locks out everyone who ever deleted an account
• A CSS rule that silently shifts the entire app by 16 pixels
• Six languages that have to be maintained with every new line of text

None of these things is big on its own. But there are hundreds of them, and each one wants to be found, understood and cleanly solved. This is exactly where it's decided whether a product feels "finished".

Deep dive 2: Daisy – building AI into a product

Daisy is the AI assistant in LaizyNote. You write to her in plain language, and she can not only answer but act: create tasks, structure projects, link contacts, summarize time and numbers. "Create a project Website with three tasks for Emma" becomes exactly those entries.

The crucial point: Daisy asks before every write action. She shows a preview – "5 tasks will be created" – and only a click on confirm executes it. AI that writes into your data on its own, without you watching, would be a breach of trust. So you always see first what's supposed to happen.

Building AI into a real product brings a new kind of challenge that classic development doesn't know: it's not predictable. The same question can be answered slightly differently twice. The model doesn't always stick strictly to the required format. Answers sometimes get too long mid-sentence. None of this can be checked with "is the code correct" – it has to be tried by hand, over and over.

Two things mattered most to me here. First, privacy: Daisy runs through a European AI provider, hosted in the EU – fitting for a product under .eu. Second, cost control: AI costs real money per request. That's why there are usage quotas and a fixed monthly cap per user, so neither you nor I get a nasty surprise. Daisy is part of the Plus plan and is continuously developed – deliberately with a visible "Beta" label, because honesty beats pretending AI is a solved problem.

The invisible work around the product

The biggest surprise wasn't the technology. It was how much is needed around the product before you're even allowed to bill a single customer.

A SaaS isn't just an app. It's also: a brand with a name, logo and voice. Legal texts, terms, a privacy policy, a service description that holds up contractually. Payment processing with subscriptions, cancellations, yearly and monthly prices, vouchers and invoices. Automated emails, backups so no data is ever lost, and processes for when someone deletes their account. Users never see most of this – but without this foundation there's no product you can trust.

The stack in brief

For those interested in the technical side – what LaizyNote is built with:

What I learned

Would I do it again? Yes, much of it exactly the same. Firebase was the right choice for a one-person project with a large feature set – it takes backup, scaling and authentication off your plate so I could focus on the product.

What I'd approach differently is the planning. With hindsight I'd cut some data structures and relationships differently from the start – things you only understand once you've built them wrong. And I'd plan for all the surrounding work – brand, law, payment – earlier instead of treating it as "I'll do that at the end".

The result is a product that's live and publicly available, with all modules in use. Anyone can start for free – which was the whole point from the beginning.