Orhan Ozalp, Developer in Toronto, ON, Canada
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Orhan Ozalp

Verified Expert  in Engineering

Back-end Developer

Toronto, ON, Canada
Toptal Member Since
September 21, 2020

Orhan has been developing software professionally since 2007. He's occupied a range of roles—as a developer, architect, team lead, and principal engineer—for various companies, including eCommerce giants, startups, and banks. Orhan has in-depth knowledge and expertise concerning back-end systems, especially systems that needed to perform under high traffic situations and to be able to scale. Orhan also is comfortable working on projects involving data processing and machine learning systems.


Amazon Web Services (AWS), NoSQL, SQL, Interviews, Scrum, Machine Learning...
Amazon Web Services (AWS), NoSQL, Interviews, Scrum, Microservices, Python, Go...
Amazon Web Services (AWS), Spring Boot, Spring, SQL, Scrum, NGINX...




Preferred Environment

C#, Go, Python, Java

The most amazing...

...thing I've developed is the service that can process the metrics of a huge system in real-time.

Work Experience

Senior Software Engineer

2019 - PRESENT
  • Developed a service that analyzes the system metrics using machine learning methods and notifies users if there is something wrong with the metric.
  • Built a data analysis pipeline that was used to add optimal restaurants to the system.
  • Created automated machine learning training procedures to replace the manual implementations for more than 600 cities.
Technologies: Amazon Web Services (AWS), NoSQL, SQL, Interviews, Scrum, Machine Learning, Microservices, Python, Java, Go

Software Development Engineer II

2016 - 2018
  • Designed and developed parts of a system to reduce the time for new carrier onboarding to Amazon from months to weeks.
  • Migrated two backbone services of the transportation department to AWS.
  • Planned the hardware capacity of the team and took actions regarding these plans such as rewriting the Lambda functions in Go.
Technologies: Amazon Web Services (AWS), NoSQL, Interviews, Scrum, Microservices, Python, Go, Java

Principal Software Engineer

2015 - 2016
  • Managed a team that was responsible of developing a marketing system, which later became the flagship product of the company.
  • Mentored engineers and participated in code reviews actively to set the quality bar high.
  • Trained others on code quality and coding best practices.
Technologies: Amazon Web Services (AWS), Spring Boot, Spring, SQL, Scrum, NGINX, Apache Tomcat, ActiveMQ, Java

Senior Software Engineer

2014 - 2015
  • Reduced network latency of the entire system by modifying the messaging protocols being used.
  • Developed a source-code search engine using Apache Lucene.
  • Developed a metric collection system to collect and analyze metrics from the entire system.
Technologies: Windows Presentation Foundation (WPF), Windows Communication Framework (WCF), ASP.NET MVC, Scrum, SQL, Java, Logstash, Kibana, Apache Lucene, Elasticsearch, C#

Software Engineer

2012 - 2014
Safkan Software
  • Designed and implemented a data crawler for fetching tourism-related data from various sources.
  • Worked on the reimplementation of gezisitesi.com (a hotel booking website). The project was successfully delivered on time.
  • Contributed to the implementation of Viplay.com, a video sharing site for Turkish users. This project was also successfully delivered.
Technologies: Interviews, SQL, C#, Java

Software Development Team Lead

2010 - 2012
  • Designed and implemented a file transfer manager for the banking framework, which was responsible for getting and processing the files from other systems/corporations.
  • Owned customer information management and user management modules for external customers. These modules were successfully integrated into the systems of four clients.
  • Played a role in the hiring process as an interviewer and did more than 30 technical interviews.
Technologies: Concurrent Programming, Apache Lucene, Apache Tomcat, Interviews, SQL, Java, C#

Software Engineer

2007 - 2010
  • Implemented an enterprise service bus based on Mule. This was the first version of the ESB that became the main communication backbone of the company later.
  • Implemented a file transfer module (and its user interface) that was responsible for processing all the incoming and preparing the outgoing files.
  • Maintained the low-latency service broker system between the ATMs and the banking servers.
Technologies: SQL, Swing, FTP, TCP, Enterprise Service Bus (ESB), Mule ESB, SOAP, Service-oriented Architecture (SOA), Unix, Java

Uber Alerts

A project involving Go-based services to analyze and take actions using Uber metrics.

The System's Three Main Back-end Services.
• A service that talks to the UI
• A service that is responsible for running the workflows
• A service that runs a Bayesian calculation and calculates thresholds for the metrics

My Role:
• Contributed to the design and development of the first service.
• Served as the architect and the main developer of the second service.
• Developed the third service by myself.

At the end of the project, we had a system that has minimal dependencies to other services and perform under very high load. Also, the Bayesian algorithm gave good results and reduced the false-positive alert rates to 10% overall.


Python, Java, C#, C, Go, SQL


Parallel Computing, Object-oriented Programming (OOP), Microservices, Distributed Computing, Agile, Scrum, Concurrent Programming, Service-oriented Architecture (SOA)


Algorithms, Artificial Intelligence (AI), Mathematics, Machine Learning, Certified ScrumMaster (CSM), Genetic Algorithms, Statistics, Probability Theory, Graphical Models, Kalman Filtering, Bayesian Inference & Modeling, Cadence, Networking, Information Retrieval, Cryptography, Robotics, Operating Systems, Pattern Recognition, Neural Networks, Support Vector Machines (SVM), Simultaneous Localization & Mapping (SLAM), Robot Operating System (ROS), Interviews, SOAP, Enterprise Service Bus (ESB), TCP, FTP


Amazon Web Services (AWS), Unix, Mule ESB


NoSQL, Elasticsearch


Apache Thrift, Swing, ASP.NET MVC, Windows Communication Framework (WCF), Windows Presentation Foundation (WPF), Spring, Spring Boot


Protobuf, Apache Lucene


ActiveMQ, Apache Tomcat, NGINX, Kibana, Logstash

2013 - 2016

Ph.D. in Computer Engineering

Istanbul Technical University - Istanbul, Turkey

2009 - 2013

Master's Degree in Computer Engineering

Galatasaray University - Istanbul, Turkey

2003 - 2007

Bachelor's Degree in Computer Engineering

Ege University - Izmir, Turkey

JUNE 2016 - JUNE 2018

Certified Scrum Master I

Scrum Alliance