Yağız Ertuğrul Kaya
Software Developer & Founder · Beynelmilel
Istanbul, Türkiye
Systems, websites and advertising for your business — built with the care we give our own products.
What Beynelmilel does
Beynelmilel is a software studio and agency founded in Bursa and working from Istanbul, Türkiye.
Everything we sell, we first built for ourselves: we learned multi-tenant architecture building a management system for Pilates studios, moderation and data safety building a social network for Erasmus students, and cost-performance trade-offs building AI products — all in our own products.
We arrive at client work carrying that experience.
Full responsibility for every project.
What we say yes to, we own end-to-end — from design to launch.
Security is not an add-on.
Row-level access control and separated privilege tables exist from day zero of every project.
All the way to production.
We deliver products that run in production — not design files.
What we do
Any kind of system or professional website; we run the advertising too.
Systems & SaaS
Custom management systems for your business: members, appointments, payments, staff — in one panel.
WhatsApp booking bot: menu, 24-hour and 2-hour reminders, cancellations, admin panel.
Professional websites
Showcase site: 4-6 pages, mobile-first, baseline SEO, privacy and cookie texts.
Showcase+: English/German, product catalogue, quote form, Google Business listing.
Advertising
- Social media management
- Meta and Google Ads
- Ad creative (visuals and video)
- Google Business and local SEO
Maintenance & audit
Maintenance: updates, backups, monitoring.
Technical audit: security and data-protection (KVKK/GDPR) technical report.
FlowDesk
FlowDesk
From clinic to factory: business management under one roof.
A multi-tenant management umbrella that unifies the shared needs of appointment-based businesses — clinics, studios, car washes, workshops. The generalised form of patterns proven in Studia.
Instead of separate software per industry, the shared backbone is written once and correctly: members, calendar, payments, staff. Industry differences plug in as modules.
- 98 database tests + 49 unit tests green
- KVKK/GDPR toolkit: data export, right to erasure, consent flow
- Clinic
- Studio
- Factory
- Car wash
Sanayi AI
Sanayi AI
The Turkish manufacturer's AI desk.
An AI platform that answers manufacturing, supply and sales questions in the language of industry. Designed for manufacturers with a credit-based usage model, an admin panel and a corporate dark interface.
General-purpose chatbots give the manufacturer general-purpose answers. Sanayi AI was built as a desk mate that understands the question in the factory's own language.
Work we delivered
Studia
End-to-end management for Pilates studios: members, class schedules, attendance, packages and instalment payments in one panel. The first studio is live and uses it every day.viva-pilates-sigma.vercel.app
AY Plastik
A TR+EN corporate site for a Bursa plastics-packaging factory founded in 1976; 32 pages with product specifications.ayplastik.vercel.app
Pilates Ebru Coşar
A one-page showcase site for a reformer studio in Nilüfer, Bursa.pilates-ebru-cosar.vercel.app
Astro Marin
A full-scope astrology platform, from natal charts to astrocartography.astromarin-app.vercel.app
EPOT Mühendislik
Six design concepts for a Bursa company that has built harmonic-filtered compensation panels since 1980.epot-tasarim-onerileri.vercel.appOur own products
Taken live under our own name.
Sanayi AI
The Turkish manufacturer's AI desk.FlowDesk
From clinic to factory: business management under one roof.Solavoy
Where to, on what budget — Solavoy plans the rest. An AI-assisted travel planner in eight languages.Erasocial
Erasmus students, meeting in the same city.Bütçem
No bank connection, no surprises: mindful budgeting.In the workshop
Not yet public — growing on our desk.
djmix
Desktop DJ setup with an Auto-Mix engine: type the track names, get a DJ-grade mix. Live Auto DJ, FX, loops, MIDI.
Oto Yıkama randevu
A no-show customer is a lost day. Takes bookings over WhatsApp and sends automatic reminders, built for small car washes.
snackboxd
Letterboxd for snacks: a 53,000-product catalogue with ratings and reviews.
Beynelmilel Platform
A data-fusion platform with link analysis, geo-temporal queries and attribute-based access control. Our most ambitious R&D project.
JARVIS
Tasks, projects, markets and a real Claude terminal — in one desktop app. A personal command centre.
FablePlanGen
A desktop tool that turns a project idea into a structured, actionable deep plan.
janestreet-sim
A quant training simulator that tests market making, ETF arbitrage and statistical arbitrage with virtual money.
CLI ajanlar
Three command-line agents: lead research, weekly competitor reports, SEO content drafts.
About me
Yağız Ertuğrul Kaya. I live in Istanbul; Beynelmilel was founded in Bursa, and my team and I run it from Istanbul.
Everything we sell, we first built for ourselves; we take a project end-to-end, from design to infrastructure, from launch to security.
For a new project, WhatsApp is the fastest way to reach me.
Let's talk
An idea, an order or just a question — write, and we'll reply the same day.
Message on WhatsApp