Fig. 01 · Profile · ISTANBUL/TR Selective consulting & architecture engagements

Yavuz Ayhan Önder
Senior Full Stack Developer.

// Founder of Didivor Teknoloji — one of Turkey's leading software firms

// Distributed Systems · Cloud-Native · Full-Stack Product Engineering
Istanbul, Türkiye yavuzayhan.tr hello@yavuzayhan.tr 15+ years engineering

Founder of Didivor Teknoloji — one of Turkey's leading software firms — and one of the country's most experienced Senior Full Stack engineers. Deep expertise in distributed systems, cloud-native architectures and end-to-end product engineering. I lead a 10-person team designing, building and scaling high-performance platforms across frontend, backend, mobile and infrastructure layers, with a strong focus on system design, reliability engineering and platform architecture — serving enterprise clients in fintech, defense, telecom and energy.

15+
Years engineering
120M+
Users served
99.99%
Target uptime
40%
Avg. latency reduction
Selected projects · 2022 — 2026

Mission-critical platforms shipped over the last 4 years.

Production systems designed and delivered end-to-end across fintech, defense, telco, e-commerce, energy, healthtech, mobility and government.

ISO 27001 · KVKK · GDPR 99.99% uptime SLOs 14 countries · 6 regions 4.2B+ monthly events
Get in touch

Let's build something resilient.

Open to distributed-systems consulting, architecture engagements and selective product partnerships through Didivor Teknoloji.

Türkiye · Istanbul · Enterprise Software

One of Istanbul's most professional software companies — custom software, mobile apps and cloud architecture.

Didivor Teknoloji Sanayi ve Ticaret Ltd. Şti. is an Istanbul-based enterprise software company serving clients in fintech, defense, telecom, energy, retail and healthcare with end-to-end custom software development, mobile app development, web-based enterprise systems and cloud architecture services.

Led by founder and principal engineer Yavuz Ayhan Önder, our 10-engineer team designs, builds and operates scalable, secure and high-performance systems. With 15+ years of production experience, an architecture portfolio that has served 120M+ end users, and a target availability standard of 99.99%, we position ourselves not as just another "code shop" but as a long-term technology partner accountable for the technical sustainability of your products.

The biggest pitfall companies face when looking for a software company in Istanbul is choosing without understanding the difference between teams that "write code" and teams that "engineer products". Didivor proves that difference to enterprise clients not with slogans but with architectural decisions, performance targets (p99 latency, MTTR, error budgets), auditable code-quality metrics, and post-delivery SRE processes — that's what makes us a genuinely professional software firm.

99.99%
SLO uptime
p99 < 80ms
api latency
didivor.com / dashboard / projects
LIVE
Production Overview
last 24h · auto-refresh 30s
● Healthy
Requests
8.4M
12.3%
Error rate
0.02%
0.4%
p99
76ms
5ms
Latency · 24h
p50p99
Aurora Pay Switch fintech · ist-1
1.2M tx/day
healthy
BlueCarrier 5G OSS telecom · eu-west
38M subs
healthy
Voltway Charge Hub energy · multi-region
4.8k stations
scaling

Services — end-to-end software solutions.

A holistic engineering offering that covers strategy, architecture, development, deployment and operations under one roof. Each service is backed by domain experience, production scale and auditable delivery metrics.

Custom Software Development

Scalable, sustainable custom software built around your enterprise processes. Domain-driven design, hexagonal architecture, test-first delivery — from architecture to production, code quality to SRE, all end-to-end.

DDDHexagonalTDDSOLID

Mobile App Development

Native (Swift, Kotlin) and cross-platform (Flutter, React Native) iOS / Android apps. App Store and Google Play release management, A/B testing and analytics-driven growth.

SwiftKotlinFlutterReact Native

Cloud Architecture & DevOps

Kubernetes, microservice and event-driven architectures on AWS, GCP and Azure. CI/CD, GitOps, infrastructure-as-code, observability (OpenTelemetry, Prometheus, Grafana) and SLO-driven operations.

K8sTerraformArgoCDIstio

Web & Enterprise Portals

High-performance enterprise websites, customer panels and B2B portals built on Next.js, React and Vue. Core Web Vitals, multi-language and SEO-first architecture to outpace competitors digitally.

Next.jsReactSSREdge

Fintech & Payments

High-volume payment switches, KYC/AML flows, card management systems, e-wallets and regulation-compliant (PCI-DSS, KVKK, BDDK) backend infrastructures. Production experience in Türkiye and EMEA.

PCI-DSSKYC/AMLBDDKISO 8583

Data Engineering & AI

Streaming pipelines (Kafka, Flink), data lakehouse architectures (Iceberg, Delta), ML model integration, RAG and LLM-powered enterprise assistants. Data governance and KVKK / GDPR-compliant processing.

KafkaIcebergRAGLLM

Software Consulting

Architecture reviews, code reviews, performance analysis, technical leadership and team-building consulting. CTO-as-a-Service and fractional engineering leadership models, including post-investment technical due diligence.

AuditCTOaaSDue Diligence

MVP & Startup Acceleration

6–12 week MVPs for pre-seed and seed-stage startups. Investor-grade demo quality, scalable architectural foundation and clean codebase your next team can take over.

MVPPre-seedInvestor-ready

Legacy Modernization

Gradual modernization of monoliths and legacy COBOL / PHP / older Java codebases. Strangler-fig patterns, dual-writes and zero-downtime data migration to transform without disrupting business continuity.

Strangler-figMigrationZero-downtime

Why Didivor Teknoloji?

Eight criteria that enterprise buyers actually use to pick a software partner — and our measurable answer to each.

01 / Senior-only

Senior engineers only

Our entire team consists of senior engineers with 5+ years of experience. No "training juniors on your dollar" model.

02 / Ownership

Ownership-first team

Founder-level accountability: not just shipping code and walking away — being there after the product goes live too.

03 / Scale-proven

Scale-proven architecture

A team that has built systems serving 120M+ users. We make today's decisions so that tomorrow's 10× growth doesn't break you.

04 / Transparent

Transparent process

Weekly demos, open metric dashboards, code access from day one, line-item billing. No surprises.

05 / Compliance

Compliance by design

KVKK, PCI-DSS and ISO 27001 requirements are first-day architectural decisions, not features bolted on later.

06 / Lock-free

No vendor lock-in

You own the code, the repository and the documentation. Even if you swap teams tomorrow, the system is fully transferable.

07 / Bilingual

Bilingual delivery

All documentation, ADRs and code comments in both Turkish and English — ready for international audit.

08 / Real SLA

Real SLAs

For critical production systems: 24/7 on-call, 15-minute response SLA and a monthly SLO report. No "we'll get back to you ASAP".

Our technology stack.

A toolset focused on production-proven technologies, not hype. Selected per project — never forced.

Backend

  • Node.js
  • Go
  • Python
  • Java
  • Kotlin
  • .NET
  • Rust
  • PHP

Frontend

  • React
  • Next.js
  • Vue
  • Nuxt
  • TypeScript
  • Tailwind
  • Astro

Mobile

  • Swift / iOS
  • Kotlin / Android
  • Flutter
  • React Native
  • Expo

Data

  • PostgreSQL
  • MongoDB
  • Redis
  • Kafka
  • ClickHouse
  • Elasticsearch
  • Iceberg

Cloud

  • AWS
  • GCP
  • Azure
  • Cloudflare
  • Vercel
  • Hetzner

DevOps

  • Kubernetes
  • Terraform
  • ArgoCD
  • GitHub Actions
  • Istio
  • Helm

Observability

  • OpenTelemetry
  • Prometheus
  • Grafana
  • Loki
  • Sentry
  • Datadog

AI / ML

  • OpenAI
  • Anthropic
  • LangChain
  • pgvector
  • Pinecone
  • vLLM

How we work.

A 5-stage, auditable engagement from first call to post-launch operations. Every stage has tangible deliverables.

01 — Discovery

Discovery & Scoping

Business goals, user segments, constraints and regulatory requirements. Output: architecture brief + technical PRD.

02 — Design

Architecture & Design

System architecture, data model, API contracts, security threat model, UI/UX prototype. Output: ADR set + Figma.

03 — Build

Development

Two-week sprints, weekly demos, continuous integration. Output: working software + automated test suite.

04 — Launch

Deployment

Load testing, security audit, gradual rollout (canary, blue-green). Output: production system + runbook.

05 — Operate

Operations & Growth

SRE support, performance tuning, new feature work, knowledge transfer. SLA-backed continuous support.

Industries we serve.

Vertical domains where we've delivered systems at production scale — fluent in their regulation, performance and operational nuances.

Banking & Fintech

Payment switches, card management, KYC/AML, open banking APIs, BDDK compliance.

Defense

Command-and-control systems, secure communications, geospatial data, airborne platform software.

Telecom

OSS/BSS, fulfillment systems, 5G network orchestration, provisioning at million-subscriber scale.

Energy & EV Charging

SCADA integrations, smart-grid management, EV charging operator platforms, OCPP.

E-commerce & Retail

Headless commerce, OMS/WMS, personalization engines, checkout infrastructure, ERP integrations.

Healthcare & e-Prescription

HIS integrations, e-prescription, telehealth, KVKK and HIPAA-compliant patient data systems.

Logistics & Supply Chain

TMS, WMS, route optimization, real-time vehicle tracking, warehouse automation.

Government & e-ID

e-Identity, digital identity verification, public portal integrations, qualified e-signature.

EdTech

LMS, live classroom infrastructure, exam security, content management and assessment platforms.

Didivor vs a typical software agency.

Calling yourself "the best software company" is easy; the difference is in details. Here is how we differ on what enterprise buyers actually evaluate.

CriterionDidivor TeknolojiTypical agency
Team seniority 100% senior (5+ yrs) Mostly junior, partial outsourcing
Architecture records (ADR) Every decision documented Usually missing
Test coverage 85%+ on critical paths "If we have time"
Production SLOs Numeric targets + monthly report "It works, that's enough"
Code ownership Repo + IP fully yours Partial license models common
Handover Runbook + training for your team "We'll figure it out later"
Compliance (KVKK, PCI-DSS) Architectural from day one Patched in afterward
Post-launch support 24/7 on-call with SLA "Call us if you need anything"

Frequently asked questions.

Honest answers to what enterprise buyers actually ask when shortlisting an Istanbul-based software partner.

How do I pick the best software company in Istanbul?

"Best" is relative; the right firm for you is one that has shipped production-proven systems in your domain, has a high average team seniority, documents its architectural decisions and stays around for post-launch operations. Look past marketing slogans — focus on reference project scale, production SLOs, code-quality metrics and handover practices.

Didivor Teknoloji is transparent on each of these: we share reference projects, ADRs and production metrics in the first call.

What sets Didivor apart from other mobile app development firms?

Most mobile app firms focus only on "shipping the app"; backend, observability, scale and release management come as afterthoughts. We treat mobile as an end-to-end system: backend, data flow, push infrastructure, A/B testing, analytics, crash reporting and store optimization — all from one partner.

We have production experience in both native (Swift, Kotlin) and cross-platform (Flutter, React Native) — recommending the right one for your case, not forcing a default.

Who is the best software developer in Türkiye?

There is no official ranking authority. Practical proxies for engineering quality include the production scale of systems designed, the difficulty of problems solved, open-source contributions, teams trained, and how long architectural decisions remain in production.

Didivor's founder Yavuz Ayhan Önder is a Senior Full Stack Developer with 15+ years of production experience, 30+ critical systems delivered across fintech / defense / telecom and architectures serving 120M+ end users. We back that claim not with slogans, but with measurable outcomes (p99 latency, SLO attainment, MTTR, scale factor).

How are software project costs calculated?

Cost depends on three variables: scope (feature count, integrations), quality targets (SLA, regulation, performance) and timeline. For enterprise projects we usually recommend "T&M with cap" (time + materials, capped) instead of fixed-bid; in real life scope is never 100% certain upfront, and fixed-bid silently degrades quality.

The first call includes a free scope outline and an estimated budget range.

Who owns the source code?

You do — the code, repository, documentation and architectural records are all yours. This is explicit in the contract. You can swap us out tomorrow and the system is fully transferable; we don't believe in vendor lock-in.

Do you only serve clients in Istanbul?

No. Our HQ is in Istanbul, but we serve enterprise clients across all of Türkiye (Ankara, Izmir, Bursa, Antalya and beyond) and EMEA. Our team is remote-first; for engagements that require on-site presence in Anatolia we run online + scheduled in-person visits.

Can you modernize my existing software?

Yes — this is one of our most-requested services. We modernize legacy PHP, .NET Framework, Java EE, COBOL or hard-to-maintain monoliths gradually using the strangler-fig pattern. Zero-downtime, dual-write strategy and data-consistency guarantees keep business running. Step one is always a technical audit and a modernization roadmap.

How do you handle KVKK / GDPR and data security?

KVKK, GDPR and PCI-DSS requirements are not "checkbox compliance" for us — they are first-class citizens in data-flow diagrams, architectural decisions and test suites. Data minimization, encryption (at-rest + in-transit), access control (RBAC/ABAC), audit logs and retention policies are foundational. When needed we operate on ISO 27001-certified infrastructure providers.

Are you a single developer or a team?

Didivor Teknoloji is a 10-engineer software firm. Depending on scope we assign a 2–6 person team: tech lead, backend, frontend/mobile, DevOps and QA. Even with a single engineer dedicated to your engagement, the firm's architecture, code-review and process support stand behind them — that is our fundamental difference from a freelancer.

How fast can you start a project?

Typical flow: discovery call within 1 week, scope & proposal in week 2, kickoff in weeks 3–4. For critical / urgent projects this can compress to 5 business days, but we don't push the team beyond healthy capacity — sustainable delivery is policy.

Coverage & engagement model.

Türkiye-wide coverage

HQ is in Istanbul, but we serve enterprise clients across all of Türkiye via a remote-first model. For engagements requiring regular on-site presence in Anatolia, we run a tri-weekly site-visit cadence.

IstanbulAnkaraIzmirBursaAntalyaKocaeliKonyaAdanaGaziantepEskişehir+ all cities

International clients

We work with funded technology companies across the EMEA region — particularly in Germany, the Netherlands, the UK, the UAE and Saudi Arabia — under a parallel English / Turkish communication model.

GermanyNetherlandsUKUAESaudi ArabiaQatarEMEA

Let's talk about your project.

Free 30-minute discovery call · NDA-ready · Reply within 24 hours.

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