A team that has spent nine years inside OpenCart.
OpencartExtra.com is the OpenCart-focused technical services brand of W3 Bilişim. We don’t sell themes or modules — we build, fix, maintain and host OpenCart stores for businesses that depend on them.
- 9+
- years with OpenCart
- 25+
- specialists in the W3 team
- 200+
- projects delivered across W3
- 2.x–4.x
- OpenCart versions supported
W3 Bilişim
W3 Bilişim Teknolojileri ve Yazılım Hizmetleri Limited Şirketi
- İstanbul
- Kartal head office
- 25+
- technology specialists
- ISO 27001
- compliant infrastructure
- Microsoft
- Partner Network member
Started with one broken checkout. Grew into a technology partner.
We began in 2017 fixing a single store’s checkout that three agencies had given up on. The owner stayed with us; so did the next one, and the next. Today most of our customers have worked with us for years.
We chose to specialize instead of generalize. OpenCart is the only platform we work on — its core, its extension ecosystem, its quirks across 2.x, 3.x and 4.x. That depth is why we can move fast and charge fairly.
We think of ourselves as the technical department our customers never had to hire: engineers who know their store, respond quickly, and take responsibility for keeping it fast, secure and online.
There is a technology company of 25 people behind our OpenCart work.
W3 Bilişim is a software company based in Kartal, İstanbul. It builds web, mobile, desktop, API and AI projects, and runs design and consulting, cloud and hosting, security and licensing under the same roof. It has completed more than 200 projects to date.
We are the part of that team that works in OpenCart. In practice that means a store request never stops at the edge of the platform: when it needs a database architect, an AWS engineer or a penetration test, the person who does it already sits at the next desk.
Software development
Web, mobile, desktop, API and AI projects.
Design and consulting
Product design, user experience and technology consulting.
Infrastructure and hosting
Cloud, dedicated servers and web hosting with a 99.9% uptime SLA.
Security and licensing
ISO 27001 compliant infrastructure, penetration testing and software licensing.
Principles that shape every ticket and every project.
Root cause, not symptoms
We find out why something broke before we fix it — so it stays fixed.
Transparency by default
Estimates before work, hours reported after. No surprises.
Upgrade-safe engineering
Event-based, versioned code that survives OpenCart updates.
Speed with care
Fast responses — but staging and tests before your live store is touched.
Plain language
We explain technical decisions in words store owners understand.
Long-term thinking
We build for the store you’ll have in three years, not just today.
Engineers first. Every one of them ships OpenCart code.
A compact senior team — you talk to the person doing the work.
Erdi Köroğlu
CEOTechnology vision, team culture and engineering quality.
Emre Yıldız
Chief Technology Officer (CTO)Technical strategy, product vision and scalable architecture.
Berk Avcı
Principal Backend EngineerREST, GraphQL and gRPC backend architecture; code review and ADRs.
Nazlı Erdoğan
Software Engineer — Node.js/PythonAPI services in Node.js and Python; test-driven development.
Sercan Öztürk
Head of SRE & Platform EngineeringCI/CD, SRE and GitOps; SLO/SLI and production incident command.
Ahmet Çelik
Cloud Architect — AWSAWS, Terraform and Kubernetes infrastructure; zero-downtime cutovers.
Elif Demir
Platform EngineerDocker, ArgoCD and internal developer platforms; edge computing.
Pınar Uçar
Performance EngineerSpeed, caching and CDN architecture; Core Web Vitals and profiling.
Cansu Yılmaz
Lead Database ArchitectPostgreSQL architecture, indexing strategies and query planning.
Zeynep Aydın
AppSec LeadOAuth, JWT and OWASP-driven security architecture; threat modelling.
Meet the team behind your next OpenCart project.
Tell us about your store. We reply within one business day.