Software, database and integration services
With more than 15 years on critical public-sector systems, I help with API development, database performance, enterprise integrations and mobile apps.
What I do
.NET backend and APIs
REST APIs, microservices and enterprise applications with ASP.NET Core; role-based authorization and Swagger documentation.
- New APIs and services
- Migrating legacy .NET Framework projects to modern .NET
- Code review and architecture advice
Database design and performance
Slow-query analysis, indexing strategy, Query Store, data migration and reporting on SQL Server and Oracle.
- Performance review with a written report
- Data model design
- Data migration between systems
Public-sector and banking integrations
e-Devlet, KPS identity checks, YÖK, TÜRSAB, bank virtual POS and payment integrations, from analysis to go-live.
- Integration analysis and delivery
- SOAP/REST service bridges
- Testing and go-live support
Mobile app development
iOS and Android apps with React Native: widgets, Apple Watch and Wear OS, in-app purchases, localisation and store optimisation.
- MVP from idea to store
- New features for an existing app
- App Store and Google Play release
Hardware integrations
Turnstiles, kiosks, handheld terminals, RFID readers, card-based access control and QR ticket validation.
- Ticketing and access control
- RFID inventory tracking
- Device-to-software communication
Security review
Baseline security review for websites and APIs: security headers, authentication and authorization design.
- Website security checklist report
- API authorization review
- Privacy-focused logging and masking
Example engagements
The scope and typical duration of common engagements. Every project is different; the exact scope and timeline are set in the written proposal.
Database performance review
I find the bottlenecks of a slow SQL Server or Oracle database and deliver prioritised, written recommendations.
Typical duration: 3–5 working days
- Most expensive queries and wait types
- Index and execution plan recommendations
- An actionable, prioritised report
Code and architecture review
I review the structure, security and maintenance risks of your .NET project and separate what to fix now from what can wait.
Typical duration: 3–5 working days
- Architecture and dependency map
- Security and performance findings
- Recommended roadmap
Integration project
I take an integration with KPS, e-Devlet, a bank virtual POS, TÜRSAB or another external service from analysis to go-live.
Typical duration: 2–6 weeks depending on scope
- Analysis and test plan
- Error and timeout handling
- Go-live and monitoring
Assessment for moving from .NET Framework to modern .NET
I assess how portable a legacy project is to modern .NET and prepare the risks, dependencies and a step-by-step migration plan.
Typical duration: about 1 week
- Dependency and compatibility inventory
- Incremental migration plan
- Effort estimate
Mobile app MVP
I turn your idea into a first React Native release on iOS and Android and publish it on the stores.
Typical duration: 6–12 weeks depending on scope
- Screen flow and scope
- iOS and Android release
- Store release with localised listings
Website and API security check
I check the baseline security of your site and APIs and present the findings and fixes in a clear report.
Typical duration: 2–3 working days
- HTTPS, headers and email records
- Authentication and authorization design
- Prioritised list of findings
What every project includes
- Source code with its version history
- Installation and configuration notes
- Tests and test scenarios
- Go-live support
- A hand-over session
- Bug-fix support for the period stated in the proposal
How we work
Short call
We talk through your need and goal in 15–20 minutes, free of charge.
Proposal
Scope, timeline and budget agreed in writing.
Delivery
Work progresses in increments you can see at every step.
Hand-over and support
Documentation, go-live and support afterwards.
Why me
Experience at real scale
Ticketing, turnstile and agency systems used across palaces and museums nationwide, running under heavy daily traffic.
End-to-end ownership
Analysis, database, backend, mobile and go-live: I think about the whole system, not just a piece of it.
A product builder
I publish my own apps in up to 14 languages, so I understand stores, users and revenue too.
Request a quote
I reply within one working day.
FAQ
Do you work with international clients?
Yes. I work remotely in English or Turkish; I am based in Istanbul (UTC+3).
Do you take on small jobs?
Yes. Limited-scope work such as fixing one slow query or a small integration is fine.
How is pricing done?
You get a written quote, either fixed price or hourly, depending on the scope.
Do you sign an NDA?
Yes. We can sign a non-disclosure agreement before we start talking details; anything you share is used only for that project.
Who owns the source code?
Unless the proposal says otherwise, the source code and rights to the delivered work are yours. The code lives in your repository; I don't build closed setups you would depend on me for.
Do you need access to our real data?
As little as possible. I prefer anonymised or test data; if real data is needed, the scope and duration of access are agreed in writing beforehand, and personal data is handled in line with KVKK and GDPR.
What happens after delivery?
Bug fixes are free for the period stated in the proposal. After that we can agree on new features or regular maintenance separately.
How many projects do you take on at once?
Only a few, so each one gets the attention it needs. We agree on a start date in the proposal.