Service 01 / 04
Custom web app and SaaS development
SaaS products, marketplaces and internal tools, designed and built by me in Next.js, TypeScript and Supabase. You talk to the engineer writing the code from the first call to launch day and after it.
In short
I design and build custom web applications: SaaS products with accounts and subscription billing, two-sided marketplaces, admin dashboards and internal tools. Most run on Next.js, TypeScript, Supabase and Stripe. A first version usually takes 4–8 weeks, at a fixed price agreed after a free estimate, and I stay on after launch for new features.
- Timeline
- 4–8 weeks for a first version
- Pricing
- Fixed price after a free estimate
- Where
- Daly City, CA · Remote across the US
- Stack
- Next.jsTypeScriptSupabaseStripe
A good fit if
- You have a validated idea and need a first version that customers can sign up for and pay for.
- Your prototype or no-code app has hit its limits, and the next version needs proper accounts, billing and a database you control.
- You’re building a marketplace: two kinds of users, payments between them, messaging and an admin view to run it all.
- Your team runs on spreadsheets and email, and a tool built around how you already work would give everyone hours back.
Probably not a fit for
- A marketing site of a few pages. A template on Squarespace or Webflow will cost less, and you can edit it yourself.
- A project that needs a team of ten from the first week. I’m one engineer, which works best when one senior person can own the whole build.
What I build
Custom SaaS products, marketplaces and internal tools, from the first version to the one that has to scale.
- 01
Accounts and roles
Sign-up, login, teams and permissions with Supabase Auth or NextAuth, and database rules that keep each customer’s data separate.
- 02
Payments and subscriptions
Stripe subscriptions, trials, one-off payments and invoices, with PayPal when your customers expect it. Marketplaces pay out to sellers through Stripe Connect.
- 03
Dashboards and admin
The screens you and your team use to run the product: customers, orders, content, support and the numbers you check every morning.
- 04
Background jobs
Queues for slow work like AI calls, imports and bulk email, so the app stays quick for everyone when traffic spikes.
- 05
Email and real-time features
Transactional email, in-app notifications, and live chat or presence when the product needs people talking to each other.
- 06
Launch
Separate preview and production environments, analytics and error monitoring in place before the first customer signs up.
How it runs
You approve a written scope and a fixed price before any work starts, then get a preview link every week.
Step 01
Scope
A call about the product, then a written scope: the screens, the data, what’s in the first version and what waits. You get a fixed price before work starts.
Step 02
Design
Wireframes or a clickable prototype of the main flows, which you review before I write production code.
Step 03
Build
A preview link every week. Accounts, billing and the admin come early, so they’ve been tested for weeks by launch day.
Step 04
Launch & grow
A production launch with monitoring in place, then new features as you learn what customers actually use.
Work in this area
All case studies
Fig. 02 · AI SaaS · Jul 2024 – present
Grubby AI
Front-end engineering for an AI writing platform with 750K users
750K total users
Case study
Fig. 03 · Online marketplace · Nov 2025 – present
One Divine Source
Taking over a two-sided marketplace and keeping it shipping
Fig. 04 · Menswear · May 2024 – present
Cypress Clothiers
A headless Shopify store with an editorial front end
$5K monthly revenue
Case studyLuna is an excellent React developer. Luna’s performance is great and the code quality is amazing too. I highly recommend and will hire again in the future.
What affects the price
Every project gets a free estimate and a fixed price in writing before work starts. Typical timeline: 4–8 weeks for a first version.
- 01How many kinds of users there are, and what each of them can see and do.
- 02Payments: one subscription plan is simpler than usage-based billing or marketplace payouts.
- 03Integrations with the systems you already use, such as a CRM, an accounting tool or an existing database.
- 04How much design exists. I can build from your designer’s files, from wireframes, or from a rough sketch.
Common questions
Something else on your mind? Email mail@bluenebula.dev.
How long does it take to build a first version?
Usually 4–8 weeks, depending on scope. You get the timeline in writing with the estimate, and a preview link every week while I build.
Which tech stack do you use?
Next.js and TypeScript for the app, Supabase (Postgres, authentication and storage) for data, Stripe for payments, and Vercel for hosting. If your product already runs on something else, such as MongoDB or NextAuth, I can work in that instead.
Can you build a marketplace with payments between users?
Yes. Stripe Connect handles onboarding and payouts for sellers or providers, and PayPal can sit alongside it. For One Divine Source, a two-sided marketplace I took over from another agency, I built credits, intro offers and a loyalty program on top of Stripe Connect and PayPal payouts.
Do you design the interface too?
Yes. Most projects start with wireframes or a clickable prototype of the main flows, and I design the interface as I build it. If you already work with a designer, I’ll build from their files.
Can you build a mobile app as well?
When it shares the web product’s accounts and data, yes. For Grubby AI I built an iOS app in Expo that uses the same accounts and subscriptions as the web app.
Further reading
Start a project
Tell me what you’re building.
Email is the fastest way to reach me, and I usually reply within a day. Or use the form, and I’ll get back to you the same way.
37.69°N 122.47°W · Daly City, CA · Remote across the US