Selçuk Cihan, Developer in Istanbul, Turkey
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Selçuk Cihan

Verified Expert  in Engineering

Serverless Developer

Location
Istanbul, Turkey
Toptal Member Since
October 9, 2018

Selcuk is a senior engineer, a certified AWS expert, and an ex-Amazonian who cares deeply about his customers. He brings a strong sense of ownership and a track record of delivering results. With over five years of experience developing serverless applications on AWS, he has a proven ability to take on technical duties, from operations to development and architecture. He has worked as a contractor for various startups, shipping numerous products and making customers happy.

Portfolio

serverless
Python 3, AWS Lambda
Tellimer
Python, Serverless, AWS Lambda, TypeScript, GraphQL, Amazon Web Services (AWS)...
Toptal Client
Amazon Web Services (AWS), AngularJS, Python, Serverless, REST APIs...

Experience

Availability

Full-time

Preferred Environment

Amazon Web Services (AWS), Serverless, Python, Node.js, TypeScript, Datadog, Elasticsearch, PostgreSQL, Next.js, AWS Lambda

The most amazing...

...project I've done is migrating from SQL to a managed NoSQL database without down time, involving three different services and over 20 different clients.

Work Experience

Senior Software Engineer

2023 - PRESENT
serverless
  • Developed the Python AWS Lambda SDK of serverless console product.
  • Implemented CI/CD on GitHub actions to automate releases and PRs.
  • Added automated tests that validate end-to-end business logic and performance.
Technologies: Python 3, AWS Lambda

Senior Engineer

2020 - 2021
Tellimer
  • Created the GraphQL back end for parsel.ai, a machine learning SaaS offering.
  • Migrated existing applications to be hosted as serverless applications (AWS Lambda).
  • Created a serverless application to source news from third-party providers.
  • Added payments on tellimer.com using Stripe. This involved extending the existing GraphQL API.
  • Created serverless workflows using AWS Step Functions to integrate with external services.
  • Created GraphQL APIs with AppSync, connecting various data sources like DynamoDB and RDS.
  • Built a serverless app that periodically maintains the sitemap for various web apps.
  • Implemented a Stripe integration for SaaS subscriptions to collect payments.
  • Architected an article recommender and summarizer for tellimer.com.
Technologies: Python, Serverless, AWS Lambda, TypeScript, GraphQL, Amazon Web Services (AWS), Amazon Cognito, Amazon EC2, Amazon Simple Queue Service (SQS), AWS Step Functions, Amazon DynamoDB, AWS AppSync, Datadog, Algolia, Stripe API, Python 3, SQL, REST APIs, Amazon CloudWatch, NoSQL, Amazon S3 (AWS S3), AWS IAM, Amazon API Gateway, AWS CloudFormation, Python 2, Jest, Serverless Framework, API Gateways, Back-end, Git, Architecture, Microservices, Amazon RDS, Amazon CloudFront CDN, Relational Databases, Integration Testing, Data Analytics, Web Scraping, Cloud Architecture, Technical Leadership, Flask, API Integration, APIs

Senior Software Developer

2018 - 2019
Toptal Client
  • Created a public-facing web application with a serverless framework.
  • Created a serverless back end in Python on AWS Lambda and API Gateway.
  • Developed and maintained the front end, implemented with AngularJS.
  • Reduced cost, resulting in more than a 50% savings on the AWS bill.
  • Mentored developers and was involved in planning and reviewing pull requests.
  • Improved performance by reengineering caching on CloudFront/S3.
  • Created serverless workflows using AWS Step Functions to integrate with external services.
Technologies: Amazon Web Services (AWS), AngularJS, Python, Serverless, REST APIs, Amazon CloudWatch, NoSQL, Amazon S3 (AWS S3), AWS IAM, Amazon API Gateway, AWS CloudFormation, Python 2, Serverless Framework, Pytest, API Gateways, Back-end, Git, Architecture, Microservices, Amazon RDS, Amazon CloudFront CDN, Relational Databases, Integration Testing, Cloud Architecture, Unix, API Integration, APIs

Software Development Engineer

2017 - 2018
Amazon
  • Developed the orchestration platform that processes Amazon's catalog. The platform can handle tens of thousands of TPS, enabling the finest and most extensive catalog on earth.
  • Added functionality to a Node.js service, a high TPS REST service for difference analysis.
  • Refactored an orchestration engine that consumes Kinesis and calls downstream services so the application can be started without any dependencies, enabling performance testing of the core.
  • Supported the reconciliation engine (Java 8) that generates the retail catalog.
  • Carried out live migrations of several web services without downtime. Successfully deprecated multiple legacy services to simplify the overall architecture and enable catalog growth.
Technologies: Amazon Web Services (AWS), Docker, JavaScript, Elasticsearch, PostgreSQL, DevOps, Agile, Spring, Linux, Node.js, Perl, Java, SQL, REST APIs, Amazon CloudWatch, NoSQL, Amazon Kinesis, Amazon S3 (AWS S3), AWS IAM, Amazon API Gateway, AWS CloudFormation, API Gateways, Back-end, Git, Architecture, Microservices, Amazon RDS, Relational Databases, Spring Boot, Integration Testing, Cloud Architecture, Unix, API Integration, APIs

Senior Software Engineer

2013 - 2017
Intertech
  • Supported the workflow engine (C#, Windows service) serving banking applications, such as loans, customer complaints, etc.
  • Set up elastic to index workflow engine documents, enabling powerful search mechanisms for the end user.
  • Designed and implemented a workforce management system that empowers the bank's operation center. The project won an award.
Technologies: DevOps, JavaScript, Unit Testing, Agile, REST, Elasticsearch, Microsoft SQL Server, C#, SQL, Back-end, Git, Microservices, Relational Databases, Integration Testing, APIs

Senior Software Engineer

2011 - 2013
Ziraat Teknoloji (formerly Fintek)
  • Designed and implemented a workflow engine running on Oracle, serving over 100,000 workflow instances daily.
  • Served as scrum master and mentored junior developers.
  • Created a workflow designer and simulator for the workflow engine.
Technologies: C#, SQL, Oracle SQL, Git, Relational Databases

Software Engineer

2010 - 2011
AirTies Wireless Networks
  • Implemented Teletext for the IPTV set-top box using C++.
  • Developed a subtitle parser in C, which was embedded in the IPTV set-top boxes.
  • Implemented a high-performance transport stream parser in C.
Technologies: Perl, Python, Linux, C++, C, Git, Unix

Software Engineer

2009 - 2009
CC Yazılım
  • Designed and implemented a cross-platform desktop client in C++ utilizing the wxWidgets GUI toolkit. The client database is SQLite.
  • Designed and implemented the corresponding backup server in Java (J2SE). An application-level protocol is implemented for client-server communication secured via SSL (OpenSSL). Stored files are encrypted (AES).
  • Designed (visual design excluded) and implemented a web portal serving online backup users. Users can download/browse backed-up files through the portal. MySQL, Apache web server, and the Django framework are utilized.
Technologies: Django, Python, C++, Java

Python AWS Lambda SDK

https://github.com/serverless/console
I've created the Python AWS Lambda SDK for a serverless monitoring product. It's a Lambda layer that auto instruments functions and emits traces displayed in the console application.

The SDK can instrument several common libraries like Flask, requests, botocore, etc.

Parsel.ai (Machine Learning App)

http://parsel.ai
I implemented the serverless back end for parsel.ai. Built it using AppSync, Lambda, and DynamoDB. Involved in all phases of the application development, from designing the API to setting up alarms and dashboards and handling operational work.

Sourcing Financial News from External Providers

https://tellimer.com/channels
I created an application using the serverless framework with TypeScript, involving S3, SQS, SNS, Lambda, and EventBridge. The application integrates third-party APIs to gather news feeds and categorizes them to present to customers.

Twitter Friends Map

https://twheat-map.selcukcihan.com/
A side project that displays the locations of the people you follow on Twitter. The front end is written with React. The back end is serverless on AWS with Node.js runtime. It's a simple project demonstrating how a fully serverless application can be built.

Tetris with React

http://tetris.selcukcihan.com/
A simple Tetris game built with React. This project shows how React can be used. The game can be played on tetris.selcukcihan.com. There is also a blog post in Turkish on https://blog.selcukcihan.com/web-development/reactris/ on the development process.

Software News Curator

https://sw-news.selcukcihan.com
This application integrates with the Twitter API to fetch trending software-related tweets. The back end is serverless on AWS using Lambda (Node.js) and S3, while the front end is on Vercel using Next.js. It also has a single page which is statically rendered at build time.

Tweeted About

http://tweeted-about.selcukcihan.com
This is a Next.js app hosted on Vercel. It fetches a Twitter user's tweet contexts to render an infographic demonstrating which topics they have been tweeting about the most. The back end is serverless on AWS and uses API Gateway, Lambda (Node.js), and S3.

Languages

Python, JavaScript, Python 2, Java, SQL, Python 3, C#, Perl, C++, C, TypeScript, GraphQL

Libraries/APIs

Node.js, REST APIs, React, Stripe API

Tools

Amazon CloudWatch, Amazon Simple Queue Service (SQS), Amazon Cognito, AWS IAM, Git, Amazon CloudFront CDN, AWS CloudFormation, AWS Step Functions, AWS AppSync, Pytest, Auth0

Paradigms

Unit Testing, Microservices, DevOps, Agile, REST

Platforms

Amazon EC2, Linux, AWS Lambda, Docker, Unix, Amazon Web Services (AWS), Algolia, Vercel

Storage

Amazon DynamoDB, Amazon S3 (AWS S3), NoSQL, Relational Databases, PostgreSQL, Oracle SQL, Microsoft SQL Server, Elasticsearch, Datadog

Other

Amazon Kinesis, Back-end, API Gateways, Architecture, Amazon RDS, Integration Testing, Cloud Architecture, Technical Leadership, API Integration, APIs, Amazon API Gateway, Web Scraping, Data Analytics, Serverless, Graph Theory, Distributed Systems, Wireless Networking, Computer Vision, Computer Science

Frameworks

Django, Spring, Serverless Framework, Spring Boot, Flask, AngularJS, Jest, Next.js

2008 - 2010

Master's Degree in Computer Engineering

Bogazici University - İstanbul, Turkey

2003 - 2008

Bachelor's Degree in Computer Engineering

Bogazici University - İstanbul, Turkey

JUNE 2022 - JUNE 2025

AWS Certified Solutions Architect Professional

Amazon Web Services

SEPTEMBER 2019 - SEPTEMBER 2025

AWS Certified Solutions Architect Associate

AWS

SEPTEMBER 2019 - SEPTEMBER 2022

AWS Certified Solutions Architect - Associate

Amazon Web Services (AWS)

JUNE 2019 - JUNE 2022

AWS Certified Cloud Practitioner

Amazon Web Services (AWS)

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