Sercan Çelenk

[Expert Software Engineer]
İzmir / Turkey · [+90 530 200 85 02] · sercancelenk@gmail.com

"Passionate about IT Profession and Computer Engineering. Have years of experience on Software Development. Designed and building several Softwares with Java, Scala, Ruby, Python. Both had experience in Startups and Enterprise Scale organizations.."

Experience

Expert Software Engineer

Trendyol Tech Group

Seller Cargo Invoice, Seller Penalty Invoice, Desi Objection, Product Listing, Customer Invoice

  • Event Driven Architecture
  • Domain Driven Architecture
  • Big Data Processing
  • Apache Kafka Experience
  • CDC Debezium, Kafka Connect Experienced
  • Java Streams, Reactive Practices
  • Postgresql, Couchbase, Redis Experience
  • Batch Processing Experienced
  • Clean Code practices
  • Junit, Mockito , PITest Experienced
  • Quarkus, Spring Native, GraalVm experienced
  • Distributed Processing Experienced
  • Kubernetes, Istio, Gitlab CI
  • Library Development as Kafka Smart Util, Smart Excel Util, Kafka Shovel
01/2021 - Present

Expert Software Engineer

Turkcell Technology

Fizy Music Platform, Magazine Platform, Online Gaming Platform, TV+ Middleware

  • Core backend development
  • Reactive Programming with Java 1.8 and projectreactor.io.
  • Reactive Manifesto, Monads, Functional Programming
  • Reactive Apache Kafka Cluster Pub/Sub Messaging and Reactive Websocket
  • 250000+ connections in one machine on T instant
  • Reactive Redis Template, Google Guava Memoizer for in-memory cache
  • Spring 5 Webflux
  • Spring Cloud Netflix Microservice Architecture, Spring Boot 2.x, Java 1.8 Functional
  • Redis Cluster, Redis Sentinel
  • Consul Service Registry, Ribbon, Zuul Filter
  • Java Concurrency for music content data polling
  • Dockerize modules, Openshift, Jenkins integration
  • Spring Cloud Netflix Microservice Architecture, Spring Boot 2.x, Java 1.8 Functional
  • Redis Cluster, Redis Sentinel
  • Consul Service Registry, Ribbon, Zuul Filter
  • Java Concurrency for music content data polling
  • Dockerize modules, Openshift, Jenkins integration
  • Hazelcast Multicast Distributed Cache
  • Replatforming Magazine Core from .Net to Java Microservices
04/2016 - 01/2021

Senior Software Engineer

Global Capital Group Online Banking Company

Project based working in Payment Team.

  • Spring Boot 1.5, Microservice Architecture, ELK, Zepplin, Zuul Filter, Mockito JUnit
10/2015 - 04/2016

Head of Core Development

Dumetech

Dumetech is startup company of us. We developed Mesaj.Ninja Project that online messaging platform via Whatsapp, Viber, Bip. Also we acquire reward from BNP Pariba International Hackhaton in Istanbul.

01/2015 - 01/2016

Senior Software Engineer

Turkcell Technology

Eclipse Plugin and Middleware development for Release Management in Turkcell.

10/2013 - 01/2015

Senior Software Engineer

Akbank Technology

Main Banking Team, development of financial applications.

04/2012 - 11/2013

Software Engineer

EG Software Company

Startup Company, Developed Government Applications and R&D Projects.

05/2010 - 04/2012

Software Engineer

Mag Software Company

Startup Company, Developed Government Applications and R&D Projects.

04/2008 - 05/2010

Projects

Smart Kafka Util

  • Easy kafka integration to your java projects
  • Support as retry, filter, low level configuration on yaml files
  • Support for jdk 11/17, Support for Spring 3.0
Personal

FlexDQ - Data Quality Tool for Integrated Systems

  • Spring boot 1.5, Java 1.8, Spring Data, Mysql DB
  • Spring Quartz Dynamic Job Scheduling
  • Hazelcast Multicast Distributed Cache
  • Dockerize modules, Openshift, Jenkins integration
Turkcell Technology

Developer of SDLC for CI / CD and Release Management Processes

  • Java 1.7, Spring Data, J2EE, Eclipse Plugin Development, Rest Api
  • Developed the following modules: Web Api, Schedule Api, Rest Api, Log monitoring Api
  • Integration of Clearcase and SVN
  • Eclipse Plugin Development, SWT adapted, Threaded GUI
Turkcell Technology

Hazzmon-io

  • Hazelcast Key and Cluster Management Tool
  • Manage your hazelcast on-demand for your project. Easy setup.
  • Github: https://github.com/sercancelenk/hazzmon-io
  • Spring Boot 2.x, Hazelcast Supported All Versions, AngularJs 6 for UI
Turkcell Technology

Mesaj.Ninja - Cloud Messaging Application via Whatsapp, Viber

  • TEB BNP Paribas Hackathon Winner Project
  • Spring Technologies, Java 1.8, Java concurrency, Ruby Cucumber Integration, AngularJs
Dumetech

Gundem.in Intelligence News Crawler Application

  • From 200+ resources, crawl and serve news data on mobile phone, Mix news with twitter and facebook
  • Apache Kafka for crawling data on demand, Ruby Sinatra Framework, Solr for indexing and grouping news
Personal

Skills

Programming Languages & Tools
  • Event Driven Architecture
  • Domain Driven Architecture
  • Big Data Processing on kafka
  • Reactive Programming, Reactive Manifesto, Scalable Systems
  • Java 1.6, 1.7, 1.8, Functional Programming, Design Patterns experience (Advanced)
  • Dockerize Applications, CI/CD, Jenkins Integrated Applications
  • Scala for multithreaded processing with functional
  • Clean code, Microservices Architectures
  • Spring Rest Docs, Mockito, JUnit
  • Spring Data, Rest, Webflux, Oauth, Hibernate, JWT (Advanced)
  • Scala for multithreaded processing with functional
  • Apache Kafka Messaging (Pub/Sub)
  • Redis Sentinel, Redis Server Cluster, Sharding
  • Hazelcast Cluster, Google Guava, Ehcache
  • Ruby (Intermediate) - Sinatra, Rails Frameworks
Workflow
  • Accept and Analyze Problem
  • Find most suitable solution
  • Develop most efficiently
  • Agile Development & Scrum

Awards & Certifications

  • (Mesaj.Ninja Project) BNP Paribas & TEB International Hackhaton Winner in ISTANBUL (2015)
  • Oracle OCA Certificate (2011) (Oracle-Ireland)
  • Java 1.8 New fetures (2015) (Oracle)
  • Java EE (2013-2014) - Oracle
  • Spring Framework Architecture (2013) (kodcu.com)
  • JavaSE and Design Patterns (2007) (Oracle)

Given Lectures

  • Startup Roadmap (I.T.U Cekirdek)
  • Reactive Programming (Turkcell Technology)
  • Java 1.8 New features (Turkcell Technology)
  • Sql Tuning (Bilge Adam)

Education

Selçuk University

Engineering Faculty - Computer Engineering Department

Graduated.

09/2003 - 09/2008

Interests

  • In my free time I like playing guitar, playing football, driving a car, and reading politics.
  • Professionally, I like to constantly develop myself, create other fields, learn other languages,produce new ideas and projects.

References

  • References will be supplied in case of request.