Available for new work·Remote · Türkiye

Ali Tunacan OnarFull-Stack Engineer building SaaS products.

Full-Stack Software Engineer with 5 years of experience designing and building SaaS products from scratch. I've worked across fintech, healthcare AI, fitness, and B2B platforms, both as part of product teams and as a freelance engineer leading end-to-end builds.

Get in touch View on LinkedIn

Experience: 5+ yrs
Products shipped: 12+
Users reached: 20k+

About

Türkiye · Remote

Full-stack engineer, end-to-end product builder.

I design and build SaaS products from scratch - both on product teams and as a freelance engineer leading complete builds. My work spans multi-tenant B2B platforms, AI-driven workflows, two-sided marketplaces, and cross-platform mobile apps.

What I care about: shipping products that actually work in production, writing maintainable code that won't haunt the next developer, and understanding the business problem before the technical one.

Default stack

Frontend

Next.js
React
React Native
TypeScript
TailwindCSS

Backend

Node.js
Express
PostgreSQL
Supabase
Prisma

Infrastructure

Vercel
Railway
Hetzner
AWS
Cloudflare

Payments

Stripe
Lemon Squeezy
Iyzico
Param

Selected work

Products I've built end-to-end.

A mix of greenfield SaaS builds, marketplaces, and rescues of stalled codebases.

Client work

Tigaa

B2B procurement SaaS with WhatsApp + AI quote engine.

Multi-tenant data model with dual buyer/supplier roles, catalogs, and quote management.
WhatsApp Business API + OpenAI bot that extracts products from PDFs and images, then generates quote documents.
Multi-channel comms (WhatsApp, SMS, email), supplier confirmation automation, analytics dashboards.

Next.jsSupabaseTypeScriptOpenAICloudflare

Live

Merit Risk Platform Rewrite

Modernizing a 10-year-old multi-tenant risk platform used by major Turkish banks.

Full rewrite from PHP/MySQL to Next.js, Express, and PostgreSQL.
Migration plan for live tenants without breaking existing risk models.
Re-architected the data layer around econometric models from the finance team.

Next.jsExpressPostgreSQLTypeScriptAWS

Client work

KolayTadilat

Two-sided marketplace for homeowners and renovation pros.

Took over a stalled AI-generated codebase and shipped it to production.
Built Express backend from scratch; redesigned the database for scalability.
Credit-based applications, milestone payments via Param, SMS verification, email.

ViteReactTanStackExpressSupabaseParam

Client work

IReturnTicket

Travel documentation SaaS for visa applicants and border crossings.

Public booking flow, admin panel, and automated PDF generation.
Licensed GDS integration for real onward/return ticket documents.
Payments + automated email delivery, deployed on Vercel.

Next.jsSupabaseLemon SqueezyResendRailway

Live

Sonic8

AI watermark generator and audio enhancement SaaS for sound files.

Inaudible AI watermarking for audio files, with Dolby APIs powering the audio enhancement pipeline.
Heavy use of Supabase Edge Functions to talk to Modal-hosted AI APIs from the serverless layer.
Auth, billing, and dashboard for processing and downloading watermarked audio.

Next.jsSupabaseClerkLemon SqueezyEdge FunctionsVercel

Client work

OneClickGenerator

AI-powered privacy policy and support page generator for mobile apps.

Generates production-ready legal pages from a few app details.
Stripe checkout, Prisma data layer, deployed on Railway.

Next.jsPrismaPostgreSQLStripeRailway

Live

Denersen

Turkish AI SaaS that turns raw product photos into professional product imagery and video.

Personal project built to explore the fal.ai image and video model APIs.
End-to-end flow from upload to generated, downloadable product visuals.
Subscription billing and full Turkish UX, currently live in production.

Next.jsTailwindCSSSupabaseLemon SqueezyRailway

Live

LoadMuscle

AI workout planner, built solo and shipped to production.

5,000+ app users and 17,000+ monthly web visitors.
React Native + Expo on mobile; Next.js on web with shared types.
Personalized programs generated from user goals and equipment.

React NativeExpoNext.jsSupabase

Work with me

Have a project in mind? Let's build it together.

Whether it's a greenfield SaaS, a B2B platform, or a stalled codebase that needs to ship, I'd love to hear about it.

Start a project

Experience

Five years across product teams and freelance builds.

Upwork - Freelance
Full-Stack Engineer · Remote
Nov 2025 - Present
Building SaaS products and B2B platforms end-to-end. Greenfield builds and rescues of stalled codebases.
- Tigaa: Multi-tenant B2B procurement SaaS with a WhatsApp Business API + OpenAI quote engine.
- KolayTadilat: Two-sided renovation marketplace - took over a stalled codebase and shipped to production.
- IReturnTicket: Travel documentation SaaS with licensed GDS integration and automated PDF generation.
- Merit Risk rewrite: Modernizing a 10-year-old multi-tenant risk platform used by major Turkish banks.
Next.jsSupabaseExpressPostgreSQLTypeScriptCloudflare
Papak Software Ltd
Full-Stack Engineer · Istanbul, Türkiye
Jun 2024 - Jun 2025
Papak builds SaaS-based products across fitness and audio tech.
- Built a cross-platform fitness application (web + mobile) with Next.js, React Native, TypeScript, PostgreSQL, and Supabase.
- Designed and shipped a SaaS for inaudible audio watermarking, integrating third-party APIs with high data integrity.
Next.jsReact NativeTypeScriptPostgreSQLSupabase
seamlessCARE Ltd
Full-Stack Software Engineer · Istanbul, Türkiye
Oct 2022 - Jun 2024
AI-powered assistive technologies for nonverbal individuals in care environments.
- Led requirements gathering, system analysis, and architectural design of a B2B SaaS product.
- Built a custom admin panel (React, Node.js, PostgreSQL, MongoDB) on AWS for internal AI service and user management.
- Developed an emotion analysis SaaS integrating a proprietary AI model for hospitals and care homes.
- Integrated Sentry for system-wide error tracking and real-time performance monitoring.
ReactNode.jsPostgreSQLMongoDBAWSSentry
Merit Risk
Junior Software Developer · Istanbul, Türkiye
May 2021 - Jan 2022
Financial risk management - SaaS products built around internal econometric models.
- Developed and reorganized business risk rating models for companies and countries.
- Built a tool to upload Excel-based risk assessment models from the finance team to the web portal.
- Owned server maintenance and professional email infrastructure.
PHPMySQLJavaScriptLaravel
Pailab
Junior Developer · Tekirdağ, Türkiye
Dec 2016 - Oct 2017
Student venture I co-founded - built websites for early-stage clients.
- Contributed to early-stage products, gaining hands-on experience in full-cycle development.
HTMLCSSPHPMySQLJavaScript

Services

How I can help.

Whether you're starting from scratch or inheriting something that no longer scales - I can take it from there.

SaaS from scratch

Greenfield builds - multi-tenant architecture, auth, billing, and the unsexy infrastructure that lets a product actually scale.

Codebase rescues

Taking over stalled or AI-generated codebases and shipping them to production. Refactor, redesign the database, fix the N+1s.

Cross-platform mobile

React Native + Expo apps with a Next.js web counterpart. Shared types, shared logic, one team shipping both.

Technical consulting

Architecture reviews, stack decisions, and second opinions before you commit to a direction that's expensive to undo.

Get in touch

Have a product idea or a stalled codebase?

Currently open to full-time roles or freelance work on SaaS products, B2B platforms, and complex full-stack builds.

Emailalitunacanonar@icloud.com LinkedIn/in/ali-tunacan-onar