Hakan Sevim: Freelance Full Stack Developer with 18 Years of Experience

18 years of building real products

Over 18 years I have built a wide range of products: engineering desktop software, iOS apps live on the App Store, multi-tenant SaaS platforms and IoT devices connected to CNC machines. That range lets me think about every layer of a project at once.

Today I work as a freelance software developer for clients across Türkiye, meeting on site in Istanbul, Izmir, Ankara, Bursa and Antalya, and working remotely with clients in Germany and Canada. Alongside my personal brand I also run projects under istanbulyazilimci.com and OMNI Robot Automation.

Areas of expertise

• iOS & mobile

  Swift, SwiftUI, Kotlin, PWA.

• Full stack web

  PHP, Laravel, CodeIgniter, React, Node.js.

• ERP / MRP

  Production, inventory, SAP and Netsis integration.

• AI

  Computer vision, LLM, RAG, CoreML.

• Embedded & IoT

  ESP32, STM32, Raspberry Pi.

• Technical SEO

  Schema, speed, AI search.

How I work

• I work with real data, not guesses: before fixing a bug I prove the root cause with logs, database queries and real request/response data.
• I read the existing structure before writing code and build in line with the architecture without breaking what already works.
• Live systems come first: regression-free, tested and reversible releases.
• Product decisions belong to my client: I present the options and their impact clearly, and we decide together.

References and media

I have worked with organizations such as Brisa, Kale Holding, Alp Havacılık, Forbest AVM and Büyük Beden Mağazaları. See more in my references, video client reviews, my appearance on TV 8.5 Life Style and my İşkolik interview (in Turkish).

Frequently asked questions