Ismail Yavuz, Developer in Istanbul, Turkey
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Ismail Yavuz

Verified Expert  in Engineering

Back-end Developer

Location
Istanbul, Turkey
Toptal Member Since
June 24, 2021

Ismail is a software engineer with several years of experience mainly with Java and RDBMS and in a range of industries including IoT, GIS, and eCommerce. Ismail excels at designing and building all parts of highly scalable and available software systems from end to end and in converting ideas and requirements into working systems. Ismail's extremely comfortable handling TB-sized databases, working with tens of thousands of concurrent TCP connections, and managing in-house and remote developers.

Portfolio

Binalyze OU
Java, Apache Tika, Jpackage, CI/CD Pipelines, Unit Testing, Coding, Java 17...
SalesArt
Java, Spring Boot, PostgreSQL, Microservices, Docker, Jenkins, JUnit, Ubuntu...
SalesArt
Java, Spring Boot, PostgreSQL, Microservices, Docker, Jenkins, JUnit, Ubuntu...

Experience

Availability

Full-time

Preferred Environment

Ubuntu, Trello, Jira, Slack, Git, Notepad++, Eclipse, Postman, Windows, IntelliJ IDEA

The most amazing...

...result that my software had was becoming the #1 choice due to the fact it was so reliable, faster, and more user-friendly than the other four alternatives.

Work Experience

Senior Java Developer

2022 - 2022
Binalyze OU
  • Developed a cross-platform CLI application, a high-performant disk scanner that supports thousands of content types.
  • Created the local pipeline to be built for Windows and Linux. Delivered a running native executable in the first week for Windows and Linux. The MVP was ready in six weeks.
  • Worked directly with the CEO and got a perfect review from him on LinkedIn, where 40+ great software engineers were working in the company.
  • Integrated the application with the agent software of the company running on tens of thousands of machines. Synced with the VP of engineers and DevOps engineers.
  • Since the application depended on many parser libraries, conflicting ones were resolved. Overrode any old-version library that came from the Apache Tika library.
Technologies: Java, Apache Tika, Jpackage, CI/CD Pipelines, Unit Testing, Coding, Java 17, VirtualBox, Ubuntu 14.04, Ubuntu, Java NIO, JUnit, JSON, Jackson, Apache Maven, Apache Commons, Azure, Git, Multithreading, Concurrency, Java Concurrency, Signals, Signal Protocols, Internationalization, Logback, log4j, SLF4J, YAML, Guava, Google Guava, Tesseract, Markdown, Linux

Software Team Lead

2021 - 2022
SalesArt
  • Led and was responsible for analyzing the business requirements and for the product's development, testing, and deployment process.
  • Shaped the company culture for the better. Applied Scrum and increased the documentation habits of non-technical and technical teams. Changed how and when we deploy in our pipeline.
  • Introduced rollback mechanisms for distributed microservices transactions by using Hazelcast.
  • Created consistency checks to catch invalid data earlier.
  • Gave priority to training junior developers: long-explained PR discussions, pair programming sessions, face-to-face or group discussions, and sharing blogs/articles.
Technologies: Java, Spring Boot, PostgreSQL, Microservices, Docker, Jenkins, JUnit, Ubuntu, Jira, Confluence, System Design, Query Optimization, Trello, Notepad++, Eclipse, Postman, Web Security, Hibernate, IntelliJ IDEA, Apache Tomcat, Apache Maven, Internationalization, Scrum, Team Management, SQL, JSON, Linux, APIs, Swagger, REST, REST APIs, Bitbucket, Architecture, Relational Databases, Technical Leadership, Networks, Jira Administration, Windows, CI/CD Pipelines, Spring MVC, Spring Microservice, Docker Compose, Microservices Architecture, PostgreSQL 10, Authentication, Authorization, eCommerce, System Architecture, IT Systems Architecture, IT Systems Engineering, SaaS, Software as a Service (SaaS), Unit Testing, Startups, Back-end, Back-end Development, Back-end Performance, Back-end Architecture, RESTful Web Services, Message Queues, Requirements Analysis, API Integration, Web Development, Robust Web Development, Software Architecture, Software System Architecture Development, Financial Software, Team Leadership, Remote Team Leadership, Integration, Data Integration, Asynchronous Programming, Software Development Management, Management, IT Management, Docker Swarm, Hazelcast, JavaScript

Senior Software Engineer

2019 - 2021
SalesArt
  • Developed the back-end parts of a sales-force automation SaaS product used by distributors like P&G and SCJ.
  • Reduced the legacy codebase by 25% thanks to refactoring authentication and authorization parts of the project where the legacy code was redundant.
  • Proposed database and system designs to handle new requirements.
  • Planned and applied scheduled database backups. Planned high-availability and disaster scenarios.
  • Managed two groups of remote developers (one from Turkey and one from India).
  • Created a very sophisticated campaign microservice from scratch, which became the most foolproof part of the software. Created an invoice module.
Technologies: Java, Spring Boot, PostgreSQL, Microservices, Docker, Jenkins, JUnit, Ubuntu, Jira, Confluence, System Design, Query Optimization, Trello, Notepad++, Eclipse, Postman, Web Security, Hibernate, IntelliJ IDEA, Apache Tomcat, Apache Maven, Internationalization, Scrum, Team Management, SQL, JSON, Linux, APIs, Swagger, Bitbucket, Architecture, REST, REST APIs, Relational Databases, Technical Leadership, Networks, Jira Administration, Windows, CI/CD Pipelines, Spring MVC, Spring Microservice, Docker Compose, Microservices Architecture, PostgreSQL 10, Authentication, Authorization, eCommerce, System Architecture, SaaS, Software as a Service (SaaS), Unit Testing, Startups, Back-end, Back-end Development, RESTful Web Services, Message Queues, Requirements Analysis, API Integration, Web Development, Back-end Performance, Back-end Architecture, Software Architecture, Financial Software, Leadership, Team Leadership, Asynchronous Programming, Integration, Software Development Management, Management

Senior Back-end Developer | Team Lead

2017 - 2019
Mahrek Teknoloji
  • Completed the launch requirements of the backend of an asset-tracking system in three months by using Java, Spring, Hibernate, Nominatim, Mapnik, PostgreSQL, PostGIS, Ubuntu, and Netty.
  • Became team lead in seven months and built and managed a software team with back-end, front-end, and mobile developers.
  • Persuaded the board to pivot their decision from outsourcing ERP software—which was to manage the facility services of the biggest airports of the world with thousands of cleaners—and then successfully developed it in-house.
  • Analyzed the ERP which had multiple features—like human resources, task management, and stock management—by gathering requirements from several operational directors.
  • Integrated the ERP with IoT devices where workers use their RF cards to mark tasks as complete.
  • Developed with a team an in-door positioning system (IPS) with iBeacon devices using the best-known IPS algorithms; also the firmware-update software for the in-house iBeacons.
  • Deployed asset-tracking software for the Turkish Ministry of Commerce's security boats when the servers were not connected to the internet.
  • Oversaw and was responsible for the servers, databases, backups, disaster recovery scenarios, SMS and email integrations, and so on.
Technologies: Java, Spring Boot, Netty, PostgreSQL, Mapnik, Nominatim, Scrum, Team Management, MQTT, Ubuntu, Jenkins, Apache Maven, Internet of Things (IoT), Query Optimization, Scalability, System Design, Notepad++, Eclipse, Postman, Web Security, Hibernate, Apache Tomcat, Socket Programming, Internationalization, Subversion (SVN), SQL, JSON, Linux, APIs, Swagger, Bitbucket, Architecture, REST, REST APIs, Relational Databases, Technical Leadership, Networks, Windows, CI/CD Pipelines, Spring MVC, PostgreSQL 10, Authentication, System Architecture, SaaS, Software as a Service (SaaS), GPS, Geolocation, Sockets, Startups, Back-end, Back-end Development, RESTful Web Services, Message Queues, Requirements Analysis, API Integration, Web Development, Back-end Performance, Back-end Architecture, Software Architecture, Bluetooth Beacons, Bluetooth, Bluetooth LE, Leadership, Team Leadership, Asynchronous Programming, Integration, Software Development Management, Management

Senior Back-end Developer

2015 - 2017
Devtakip Asset Tracking Systems
  • Analyzed and developed the back end of a brand-new asset tracking system that supported many different device protocols; launched the first version in five months.
  • Built a product that was extremely sales-friendly; the company had four software types that their sales team could sell, however, after a month after launch they preferred ours since it tended to be more reliable, faster, and more user-friendly.
  • Developed software that Shell Turkey sold a white-label product version (Shelltts.devtakip.com).
  • Provided GPS and G sensor data to a driving-analyze software (Iugo.tech) and presented reports to customers.
  • Managed tens of thousands of concurrent TCP connections from devices and incoming data for instant events like ignition, driver change, custom-region enter/exit, online/offline status, crash data to inform users via email, SMS, or push notifications.
  • Built a back end that was robust enough to handle daily tens of gigabytes of new data stored on SQL Server and many different reports generated from terabytes of data with billions of rows.
Technologies: Java, Spring, Hibernate, SQL Server 2012, Netty, Ubuntu, Query Optimization, Scalability, System Design, Internet of Things (IoT), SQL Server DBA, Notepad++, Eclipse, Postman, Web Security, Apache Tomcat, Apache Maven, Socket Programming, Internationalization, SQL, JSON, Linux, APIs, Bitbucket, Architecture, REST, REST APIs, Relational Databases, Networks, Windows, Spring MVC, Authentication, System Architecture, SaaS, Software as a Service (SaaS), GPS, Geolocation, Sockets, Startups, Back-end, Back-end Development, RESTful Web Services, Message Queues, Requirements Analysis, API Integration, Web Development, Back-end Performance, Back-end Architecture, Software Architecture, Asynchronous Programming, Integration

Senior Full-stack Software Developer

2014 - 2015
Kuzzum Children Tracking System
  • Developed a brand new children-tracking software from scratch as a full-stack developer and launched it in 3.5 months.
  • Worked with Spring MVC, Hibernate, SQL Server, jQuery, Bootstrap, Netty, and JSP as my main tech stack.
  • Trained interns and helped them to develop the official website which included a simple eCommerce to enable online shopping with credit cards for our customers.
  • Implemented a trilateration algorithm to estimate latitude/longitude of a device where input was signal strength to each base station in cases when GPS signals weren't available for devices.
Technologies: Java, Spring, jQuery, HTML, CSS, Bootstrap, IntelliJ IDEA, Jakarta Server Pages (JSP), Apache Tomcat, Apache Maven, Query Optimization, Scalability, System Design, Internet of Things (IoT), SQL Server DBA, Windows Server, Trello, Notepad++, Eclipse, Postman, Web Security, Netty, Hibernate, Socket Programming, SQL, JSON, JavaScript, APIs, REST, REST APIs, Relational Databases, Networks, HTML5, CSS3, Full-stack, Windows, Spring MVC, Authentication, eCommerce, System Architecture, SaaS, Software as a Service (SaaS), Front-end, GPS, Geolocation, Sockets, Startups, Back-end, Back-end Development, Front-end Development, RESTful Web Services, Leaflet, API Integration, Full-stack Development, Web Development, Back-end Performance, Back-end Architecture, Software Architecture, Asynchronous Programming, Integration

Junior Java Developer | SQL Server Database Administrator (DBA)

2012 - 2015
Solit Asset Tracking Systems
  • Rewrote most of the reports which resulted in up to 18x faster reporting; also created a progress bar for long-running reports.
  • Split the reporting database, introduced table partitioning, and extended monitoring capabilities which enabled us to minimize live-tracking delays; was also responsible for the backups and security of the TB-sized database.
  • Supported seven languages and all time zones including Latin, Cyrillic, and Arabic alphabets.
  • Prevented memory leaks of the Swing application by using the VisualVM tool.
Technologies: Java, Swing, Apache Ant, Jakarta Server Pages (JSP), Java Web Start, Java Servlets, JasperReports, Hibernate, Windows Server, Socket Programming, Internationalization, Trello, Subversion (SVN), JVisualVM, Query Optimization, Scalability, Internet of Things (IoT), SQL Server DBA, Notepad++, Eclipse, Web Security, Apache Tomcat, SQL, APIs, Relational Databases, Networks, Windows, System Architecture, SaaS, Software as a Service (SaaS), GPS, Geolocation, Sockets, Startups, Back-end, Back-end Development, API Integration, Back-end Performance, Asynchronous Programming, XML, Integration

Internet of Things Back End

I created many asset-tracking software systems, including GPS- and indoor-based (iBeacon).

Features:
• The software can handle any number of concurrent connections.
• Collect the data from devices with any protocol at the same time.
• Live-tracking and instant custom rule-checking are supported.
• A bunch of integrations (for example, reverse geocoding) can be made instantly.
•Terabytes of data can be processed to generate overview or detailed reports.
2021 - 2022

Master's Degree (Cont.) in Computer Science

Marmara University - Istanbul

2015 - 2020

Bachelor's Degree in Computer Science

Marmara University - Istanbul, Turkey

Libraries/APIs

Java Servlets, REST APIs, Sockets, jQuery, JasperReports, Leaflet, Java NIO, Jackson, SLF4J, Guava

Tools

Trello, Apache Maven, MQTT, Jira, Slack, Git, Notepad++, Postman, Apache Tomcat, Confluence, Bitbucket, IntelliJ IDEA, Apache Ant, Subversion (SVN), Jenkins, JVisualVM, Docker Compose, Docker Swarm, Apache Tika, VirtualBox, Java Concurrency

Frameworks

Spring Boot, Spring, Hibernate, Spring MVC, Netty, Jakarta Server Pages (JSP), Swing, Java Web Start, Spring Microservice, Bootstrap, JUnit, Swagger, Google Guava

Languages

Java, SQL, JavaScript, C, HTML, CSS, HTML5, CSS3, Python, XML, YAML, Markdown

Paradigms

Socket Programming, REST, Back-end Architecture, API Architecture, Microservices, Scrum, Microservices Architecture, Requirements Analysis, Asynchronous Programming, Management, Agile, Model View ViewModel (MVVM), Unit Testing, Testing, DevOps

Platforms

Eclipse, Ubuntu, Linux, Windows, Windows Server, Docker, Firebase, Android, Bluetooth LE, Ubuntu 14.04, Azure

Storage

JSON, Relational Databases, PostgreSQL, SQL Server DBA, SQL Server 2012, PostgreSQL 10, Data Integration, Hazelcast

Other

Query Optimization, Scalability, System Design, Internet of Things (IoT), Internationalization, APIs, SaaS, Software as a Service (SaaS), Startups, Back-end, Back-end Development, RESTful Web Services, API Integration, Web Development, Back-end Performance, Software Architecture, Software System Architecture Development, Architecture, Technical Leadership, Jira Administration, Authentication, Authorization, eCommerce, System Architecture, GPS, Geolocation, Message Queues, Documentation, Financial Software, Bluetooth Beacons, Leadership, Team Leadership, Integration, Software Development Management, Web Security, Mapnik, Nominatim, Team Management, Networks, Full-stack, CI/CD Pipelines, Front-end, Front-end Development, Full-stack Development, Bluetooth, Natural Language Processing (NLP), Game Theory, Machine Learning, IT Systems Architecture, IT Systems Engineering, Robust Web Development, Remote Team Leadership, IT Management, Jpackage, Coding, Java 17, Apache Commons, Multithreading, Concurrency, Signals, Signal Protocols, Logback, log4j, Tesseract, GPT, Generative Pre-trained Transformers (GPT)

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