Rules where they cannot drift
Numbers that must agree everywhere, such as document numbers and order totals, are computed in the database rather than in each screen.
In production
Three web apps, three different problems
An internal system for a factory, a public data product and a platform for students and teachers. Each case study has screens, architecture and the full stack.
Internal system
SPSTARPLAST manufacturing ERP
Sales, production, quality, shipping and purchasing for an insulation-anchor manufacturer in one system, with per-user access to 14 functional areas, a company-wide activity feed and two-way sync with the company's LOGO ERP. The core calculations run as PostgreSQL functions and triggers.
- stack
- Next.js 15, React 19, TypeScript, Tailwind v4
- data
- Supabase PostgreSQL and Auth, 90+ tables
- scale
- 16 modules, 50+ screens, 17+ active users
- status
- In production; handed over in September 2026
Public data product
Sağlama
A public site, a ratio engine and a read-only JSON API. A Python pipeline reads companies' financial statements, records a SHA-256 hash for every file it fetches, and publishes each figure with its numerator, denominator, threshold, date, method version and source.
- stack
- Next.js 16, React 19, Python, PostgreSQL
- parsing
- pdfplumber, pdfminer.six, Playwright
- api
- Read-only JSON, in open preview
- status
- Live at saglama.com since 17 July 2026
Platform for a school
Ev Çalışması Merkezi
Students upload photos of handwritten homework; each question is marked and explained, and teachers see the whole class. A teacher's override always wins over the AI's verdict, and class rosters sync with the school portal.
- web
- Next.js 16 and React 19 on Vercel
- backend
- FastAPI API and a separate worker on Render
- data and models
- Supabase Postgres; Gemini and Claude models
- status
- Live since May 2026; grades 5 to 8 since September
How they are built
Habits taken from those three projects
Access decided once
One permission model drives the routes, the menu and the data a user can read, so a hidden button never hides an open door.
A trail for every change
Audit trails, activity feeds and dated correction logs, so anyone can see who changed what and when.
People over the AI
Where AI makes a call, a person can review it and overrule it, and the overrule is what counts.
Slow work off the request path
Grading, parsing and syncing run in workers and scheduled jobs, so pages stay fast while heavy work happens elsewhere.
Yours at the end
Clean repository, English documentation and a technical-debt report, with code, database and hosting in your own accounts.
Business websites
Smaller builds on the same stack
Client websites are built mostly with Next.js, React, TypeScript and Tailwind CSS and deployed on Vercel. These are live on the clients' own domains:
- SPSTAR: an English and Turkish product catalog with product-code search for an insulation-anchor manufacturer
- Tinyhouse Atelier: a site for a builder of steel-framed tiny houses exported to the UK and EU, with seven models, spec books and a quote basket
- SpineMedTR: a Turkish and English site for an Istanbul health tourism agency, with appointment requests
- Çekinmez Law Firm: a site for an Ankara law firm, with its practice areas and sectors
- VİP Barber Adem: a Turkish and English site for a barber in Fethiye, with WhatsApp booking
Good fit
- Internal systems that replace spreadsheets and paper forms
- Portals where customers, students or staff each see their own data
- Data products that publish numbers with their sources, with an API
- Web apps with AI features that people need to check
For typical budgets by project type, see the software development pricing guide.
You talk to the person who writes the code. Savas Tutumlu founded Stratagem Systems in Houston in 2023 and now works from Istanbul.
Have a workflow that outgrew its spreadsheet?
Describe who uses it, what data it holds and which systems it must talk to. The first call ends with a clear view of what a first version would include.
Or email info@stratagem-systems.com