Backend & APIs
Testable, documented APIs and background services on .NET 8/10 following Clean Architecture principles.
.NET İzmir, Türkiye
Onur Civanoğlu
Senior .NET Backend Engineer .NET · Distributed Systems · AI/LLM Integration
I am a .NET backend developer based in İzmir. For 7+ years I have been building multi-tenant SaaS products, ERP/e-invoicing/payment integrations and LLM-powered features with C# and ASP.NET Core, owning them from domain modelling to production deployment.
7+years of experience
1,000+commits (on a single SaaS product)
20portfolio projects
7AI / LLM projects
What I do
Backend systems owned end to end
AI & LLM Integration
Provider-agnostic AI gateways, structured outputs, chat assistants, OCR and speech-to-text workflows.
Integrations
Idempotent, rate-limit-aware and observable integrations with ERP, e-invoicing and payment systems.
DevOps & Infrastructure
Production setup, deployment automation, backups and security with Docker, Linux, Nginx and AWS.
AI engineering
Turning LLMs into production-grade product features
Not demos: AI features that ship with authentication, logging, cost control and fault tolerance.
- Single-interface AI gateway for OpenAI, Gemini, OpenRouter and Hugging Face
- Structured outputs validated against JSON schemas with typed results
- Prompt management, conversation memory and persona-based assistants
- OCR + LLM and speech-to-text document and audio pipelines
- AI-assisted development workflows with Claude Code, Codex and MCP
Embeddable Gemini Chatbot.NET 8 · Google.GenAI · Gemini 2.5 Flash
SyncFlowAI — WhatsApp Business AI Flow Platform.NET 10 · Clean Architecture · MongoDB
AI Digital Transformation Pre-AssessmentNext.js · TypeScript · OpenAI
OnurC.AiRouter — .NET AI Gateway Library.NET 8 · C# · OpenAI
PerAsist — AI Expert Assistant Platform.NET 8 · EF Core · OnurC.AiRouter
OCR + LLM Document Processing ServiceNode.js · TypeScript · Tesseract.js
Speech-to-Text Transcription APIASP.NET Core · C# · Amazon Transcribe
Experience
Career journey
Eralp Yazılım A.Ş.
Jul 2023 – PresentBackend Developer · İzmir, Türkiye
Responsible for backend architecture, integrations, AI features and server infrastructure across the company's SaaS products and client projects.
.NET 8/10C#MongoDBMySQLRedisDockerLinuxAWSOpenAIGeminiArute Solutions A.Ş.
Dec 2022 – May 2023Software Engineer · İstanbul, Türkiye
Developed database and backend modules for client projects and ran server release processes.
.NET CoreC#MS SQL ServerRESTJWTSwaggerFace Yazılım ve Danışmanlık A.Ş.
Jul 2021 – Jun 2022Software Developer · İzmir, Türkiye
Worked across the database, backend and frontend layers of a commercial, multi-customer CRM product.
ASP.NETC#MS SQL ServerWCFRESTjQueryFlutterNetspeed İnternet A.Ş.
Jul 2019 – Jul 2021Software Developer · Denizli, Türkiye
Developed an internet service provider's in-house CRM and operations systems end to end (joined as an intern in Jun–Jul 2019).
ASP.NET MVCC#MS SQL ServerSOAPJavaScriptjQuery
Selected work
Featured projects
SaaS & Backend2023 – 2026
Field Sales & CRM SaaS Platform
Multi-tenant SaaS platform giving field sales teams order, invoicing, customer and CRM management. I am the primary backend engineer and built most of the product across 1,000+ commits.
AI & LLM2025
Embeddable Gemini Chatbot
Gemini-powered customer assistant and management API that can be embedded into websites via iframe and runs with audience-specific system prompts.
AI & LLM2026
SyncFlowAI — WhatsApp Business AI Flow Platform
Backend for a platform that lets businesses build AI-driven conversation flows and lead capture scenarios on WhatsApp Business.
SaaS & Backend2023 – 2026
Online Academy / E-Learning Platform
Backend of an e-learning platform with courses, videos, books, events, assignments, quizzes, promotions and subscriptions.
Integration2026
Multi-Tenant e-Invoice / e-Archive Service
Multi-tenant e-Invoice/e-Archive service integrated with Uyumsoft, with separate admin and tenant workspaces and a management panel.
SaaS & Backend2023 – 2026
Subscription, Payment & Shared Microservices
Subscription management, payment, file management, authentication and e-mail services that different products can integrate with easily.
Let's build something together
If you have a project that needs backend architecture, integrations or AI features, let's talk.