Reha Sönmez
Verified Expert in Engineering
Back-end Developer
Amsterdam, Netherlands
Toptal member since December 7, 2018
Reha is a passionate problem solver with a background in physics, business, and economics. He has created full-stack apps with several frameworks, including React, Angular, and.NET. He moved into back-end development with Go for high-scale distributed systems involving ad tech, search, and other data-intensive workflows. Reha is also a certified Scrum PSPO who facilitates working with teams and can contribute to business decisions. He has worked with Elasticsearch, Redis, MySQL, and Kubernetes.
Portfolio
Experience
- Back-end - 5 years
- REST - 5 years
- Python - 4 years
- Large-scale Distributed Systems - 4 years
- Distributed Systems - 4 years
- Go - 3 years
- Elasticsearch - 3 years
- Full-stack - 2 years
Availability
Preferred Environment
Go, Distributed Systems, Back-end, Python, JavaScript, Java, Architecture
The most amazing...
...product I've worked on is a multi-data center, a high-load ad tech system for a big (if not the biggest) marketplace in the world.
Work Experience
Core Software Engineer
Booking.com
- Worked on building a modern global system that works with compliance across 180 countries.
- Built and improved CI/CD pipelines to automate workflows to improve developer efficiency.
- Modernized legacy systems to streamline data processing and data consistency across business layers.
Senior Back-end Developer
eBay
- Served as a senior back-end engineer for eBay's adtech product, supporting international tenants across multiple countries and time zones with a fully distributed architecture.
- Contributed to domain-driven design and distributed systems engineering, while Agile methodologies were part of the engineering process.
- Developed a microservices architecture with event stream processing.
- Scaled distributed systems to provide advertising inventory management and performance tracking.
- Optimized search performance for a 10,000 requests per second load.
- Worked on revenue optimization by engineering sophisticated mechanisms to search and rank the advertising inventory.
Full-stack Software Developer
Vixion BV
- Contributed to an automated PDF decomposer system for processing salary information and a calculation engine for pension funds. Mentored junior developers.
- Worked on an account and budget management system for supercomputer usage for academic institutions. Served a role similar to a technical product owner throughout the project and the product owner.
- Worked on a microservices-based financial investment tracking and management system for investment funds. Worked on domain-driven design sessions with the client and event sourcing sessions with the team.
Elite Full-stack Developer
Fitbrix (Toptal Client)
- Made an overall codebase review and identified problematic points for scaling the app.
- Worked on business decisions behind UX flow and created a basic framework for pushing features into the app.
- Identified basic security threats of the existing codebase.
Full-stack Developer
Drive Society
- Created the backbone of a client background checking system for B2B customers with a team of seven developers.
- Integrated three client-side apps with a comprehensive back-end application.
- Managed integration and deployment of the end-to-end MVP application.
- Continued the maintenance and feature additions through the app.
- Integrated facial recognition and financial background checks using APIs provided by third parties like Microsoft and the Dutch government.
Software Project Manager
Securitas TR
- Delivered concurrent enterprise projects with a team of nine developers.
- Delivered an Android Guard Management System as a project manager based on .NET back-end and Java client. Working 24/7 on nearly 1,000 devices.
- Delivered and intra-company Facebook with extended features like payroll and internal communication system with a team of four developers including Android, iOS, and a web app (Angular) which is still being used by 13,000 employees.
- Delivered a customer reporting tool with dynamic report generation.
- Delivered and deployed an R&D project including hardware to track the mobile devices in a closed environment.
Business Consultant
Omega Marketing Technologies
- Streamlined software product life cycles. Reduced duration acquiring customer process.
- Simplified requirement analysis process. Re-designed organizational structure.
- Introduced standardized pricing structure for the SaaS products.
Experience
Senior Back-end Engineer
Personal Portfolio and Resume
http://www.reh.asAdvertising Engine for Two-sided eBay Marketplaces
http://www.marktplaats.nlEducation
Master's Degree in Science and Technology
Middle East Technical University - Ankara, Turkey
Bachelor's Degree in Business Administration
Middle East Technical University - Ankara, Turkey
Certifications
Data Structures and Algorithms Nanodegree Program
Udacity
Full Stack Web Developer
Codaisseur Academy
Front End Web Development
freecodecamp.org
Professional Scrum Product Owner
Scrum.org
Skills
Libraries/APIs
React, REST APIs, Node.js, Web API
Tools
Grafana, Docker Compose, Hashistack, ChatGPT
Languages
JavaScript, Python, HTML5, CSS, SQL, Go, HTML, C#, TypeScript, C#.NET, Python 2, Python 3, Java, TypeScript 3, Perl
Frameworks
Express.js, Koa, Flask, Angular, Django, Django REST Framework, gRPC, Selenium
Paradigms
Agile Software Development, REST, Automation, Microservices, Asynchronous Programming, Hosting, Object-oriented Programming (OOP), Linear Programming, Agile, Scrum
Platforms
Apache Kafka, MacOS, Docker, Azure, Amazon Web Services (AWS), OpenStack, Google Cloud Platform (GCP), Kubernetes, Raspberry Pi, AWS Lambda
Storage
PostgreSQL, MySQL, Redis, MongoDB, Microsoft SQL Server, Elasticsearch
Other
Architecture, Certified Scrum Product Owner (CSPO), Full-stack, Prometheus, API Integration, Web Development, Scalability, Data Scraping, Bots, Back-end, Distributed Systems, Management Consulting, Data Structures, Algorithms, Large-scale Distributed Systems, Data Center Infrastructure, Consul, Search Engines, Advertising Technology (Adtech), APIs, Lean Project Management, Research, Full-stack Development, Product Owner, CI/CD Pipelines, OpenAI, FastAPI, PDF
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