Konstantinos Giannelos, Developer in Athens, Central Athens, Greece
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Konstantinos Giannelos

Verified Expert  in Engineering

Software Developer

Athens, Central Athens, Greece
Toptal Member Since
December 21, 2021

Konstantinos is a future-oriented professional with an exceptional blend of technical acumen and passion for building novel software, tools, and methodologies to drive fundamental, far-reaching changes. He has expertise in designing scalable, redundant, and cost-efficient solutions on the AWS platform. Instrumental for companies of all sizes, from startups in the early stages to enterprises, he played a key role in the cloud adoption journey of his clients.


CherryCircle Software
Amazon Web Services (AWS), React, Node.js, Serverless, Amazon Aurora...
Docker, Amazon EC2, AWS Direct Connect, Amazon Virtual Private Cloud (VPC)...
Amazon Web Services (AWS), AWS Certified Solution Architect




Preferred Environment

React, JavaScript, Node.js, Windows, Linux, Infrastructure as Code (IaC), Serverless, AWS Cloud Architecture, AWS CLI, Amazon Web Services (AWS)

The most amazing...

...thing I've developed is a 2D network graph visualization that made its way as a publication to pharmaceutical engineering on ISPE.org.

Work Experience

Senior Solutions Architect

2017 - PRESENT
CherryCircle Software
  • Implemented code product features like risk maps, risk tables, process flow maps, risk management plans, AI smart import, core file management, data replication capability, and many others.
  • Created functional UI test cases and resolved bugs.
  • Handled the implementation of the enterprise IT package version of the product, a multi-region deployment capability, so that the product can be deployed to multiple AWS regions.
  • Implemented a CI/CD pipeline for deploying and testing new software releases on the AWS cloud.
  • Integrated the product infrastructure as code on AWS.
Technologies: Amazon Web Services (AWS), React, Node.js, Serverless, Amazon Aurora, AWS CloudFormation, Amazon DynamoDB, Amazon Simple Queue Service (SQS), Amazon Simple Notification Service (Amazon SNS), AWS Lambda, AWS X-Ray, Infrastructure as Code (IaC), AWS Cloud Architecture, DevOps, Software Engineering, JavaScript, AWS Certified Solution Architect, AWS Certified SysOps Administrator, REST, WebSockets, MySQL, AWS Amplify

Chief Architect

2015 - 2017
  • Increased the product's uptime from less than 80% to more than 99.5% and helped Aurea regain customers' confidence.
  • Invented innovative cloud migration methodology to migrate enterprise software with minimal downtime; successfully applied solution to four new business acquisitions.
  • Prepared team to excel in the cloud and AWS space by providing effective technical guidance and training, including writing hundreds of documents for technical run books and defining standards for cloud migration.
  • Oversaw migration of 500+ servers in diverse environments, including Windows, Linux, Microsoft SQL Server, Microsoft Exchange, Microsoft SharePoint, Oracle, Sterling B2B, Tcl Web, .NET, Java, Perl, MySQL, and PHP.
Technologies: Docker, Amazon EC2, AWS Direct Connect, Amazon Virtual Private Cloud (VPC), Amazon Web Services (AWS), Migration, IT Networking, IT Project Management, Amazon Simple Email Service (SES), Amazon Route 53, DNS, Azure Active Directory, Amazon RDS, Amazon CloudWatch, Incident Management, Jira, Cross-functional Team Leadership, AWS Certified Solution Architect, AWS Certified SysOps Administrator

SaaS AWS Architect

2014 - 2016
  • Accomplished $2,000,000+ annual savings on AWS infrastructure costs.
  • Documented cost optimization run books and built the foundational standards for future deployments on AWS.
  • Collaborated with SaaS teams on AWS cost optimization projects and supervised all planned cost-saving activities.
Technologies: Amazon Web Services (AWS), AWS Certified Solution Architect

Senior Manager | QA Architect

2010 - 2014
  • Conceptualized, prototyped, and patented innovative test coverage model applicable to all software products and transparent to all tech stacks (US patent application #14/689645).
  • Delivered technical leadership to all QA projects for clients such as Wells Fargo, General Motors, Fannie Mae, and Deutsche Bank; architected and prototyped custom production validation solution for Deutsche Bank London.
  • Spearheaded the design of multiple tools to automate testing, increase productivity, and enforce quality standards of produced test cases to stability levels above 99%.
  • Built the foundation of the test cases factory and tools, such as screen coverage tool using C#, ASP.NET, JavaScript, and Microsoft SQL Server, TestComplete test automation bot using C#, XML, and WCF, and NameMapping bot using C#, WPF, and WCF.
Technologies: TestComplete, Amazon Web Services (AWS), JavaScript, SQL Server 2005, Cross-functional Team Leadership


QbDVision is a platform purpose-built to accelerate the drug development cycle, increase the probability of technical success, and help get therapeutic breakthroughs to patients that much faster.

I was the first employee to join a visionary startup aiming to disturb the life sciences industry. I have been instrumental in defining the technical roadmap for a suite of software solutions for managing the lifecycle of pharmaceutical products and the evolution of process development and validation.

This was a multi-hat role with responsibilities for:
• Software architecture, making code contributions, designing product APIs, and evaluating technology options and vendors.
• Infrastructure design for product redundancy, scalability, resiliency, and cost optimization.
• DevOps, product monitoring, and enabling developers through automated and scalable CICD pipelines.
• Centralizing operations and reducing overhead.
• Securing software and infrastructure.
1998 - 2004

Master's Degree in Electrical and Computer Engineering

National Technical University of Athens - Athens, Greece


Machine Learning



AWS Certified Developer Associate



AWS Certified DevOps Engineer Professional


MARCH 2018 - MARCH 2024

AWS Certified Solutions Architect – Professional

Amazon Web Services


AWS Certified SysOps Administrator Associate



AWS Certified Solutions Architect Associate



React, AWS Amplify, Node.js


AWS CloudFormation, AWS IAM, Amazon CloudWatch, AWS CloudTrail, Amazon EBS, AWS SDK, AWS ELB, Amazon Textract, AWS CodeDeploy, AWS CodeBuild, AWS Fargate, AWS CLI, Amazon Virtual Private Cloud (VPC), Amazon CloudFront CDN, Amazon Simple Queue Service (SQS), Amazon Simple Notification Service (Amazon SNS), Amazon Cognito, Amazon Athena, Amazon Simple Email Service (SES), Amazon WorkSpaces, AWS CodeCommit, Jira, CircleCI, AWS Systems Manager, Amazon Elastic Container Service (Amazon ECS), AWS AppSync, Amazon OpenSearch, AWS Key Management Service (KMS), Amazon QuickSight, Amazon Elastic Container Registry (ECR), AWS Glue


AWS Lambda, Amazon Web Services (AWS), Amazon EC2, TestComplete, Windows, Linux, AWS Elastic Beanstalk, Docker


Relational Databases, Amazon S3 (AWS S3), Amazon DynamoDB, Amazon Aurora, AWS Snowball, SQL Server 2005, AWS CodeStar, Azure Active Directory, MySQL




DevOps, REST


Serverless, AWS Cloud Architecture, Business Continuity, Cloud Security, Infrastructure as Code (IaC), AWS Organizations, Identity & Access Management (IAM), AWS Certified Solution Architect, Migration, Software Engineering, AWS CodePipeline, Amazon RDS, AWS Secrets Manager, Web Application Firewall (WAF), AWS Auto Scaling, Amazon API Gateway, AWS Cost Explorer, Relational Database Services (RDS), AWS Control Tower, Trusted Advisor, Single Sign-on (SSO), IT Project Management, Amazon Route 53, DNS, AWS Certified SysOps Administrator, Cross-functional Team Leadership, Machine Learning, Incident Management, AWS SAM, AWS X-Ray, Amazon Kinesis, Amazon EventBridge, Logistic Regression, Artificial Neural Networks (ANN), Machine Learning Algorithms, AWS Direct Connect, IT Networking, WebSockets

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