Oleksandr Kostenko

Background

About Oleksandr Kostenko

I am a Back-End Developer and Technical Lead with ten years of experience designing and implementing web services. For the past five years, I have been working with the AWS ecosystem, using Infrastructure as Code (CDK and TypeScript) to build serverless services that meet business requirements. My IT path began in Ukraine, where a school IT subject introduced me to Pascal and ignited my passion for coding. At university, I explored C# and C++, and later started learning Java. Since my first job in 2015, I’ve learned that programming languages and frameworks are just tools for specific tasks. We just need to be able to adapt to the new technologies. As a result, I now work extensively with TypeScript as the primary language for AWS CDK and Lambda projects. Over the years I’ve been in different roles from Developer/Lead Developer to Technical Lead, and have gained wide experience- Led cross-functional teams of 3–5 engineers, interviewed dozens of candidates, and mentored junior developers- Communicated closely with integration teams, architects, business analysts, and clients. My conclusion is that clear requirements are often the most critical factor for project success. Some highlights of my work- Legacy replacement: Designed an AWS serverless solution to retire a mainframe system, saving over $1 million annually- Platform migration: Upgraded services to the latest Java versions; managed VMs with Ansible and Puppet; containerized legacy VMs into Docker for Kubernetes (at least on the level of proof-of-concept); built CI/CD pipelines; and migrated services from Concourse to Jenkins- Serverless refactoring: Identified that a Lambda had been misused and developed as a complex microservice. Refactored the workflow with AWS Step Functions, dividing a monolithic Lambda into simpler functions, improving maintainability and alignment with serverless principles. I am excited about generative AI’s potential to accelerate development, automate documentation, and solve complex tasks. Rather than replacing humans, AI will become a powerful companion across many areas, with software engineering being a main example where it can enhance every phase of the development process. Currently, I am interested in Lead Developer or Technical Lead roles focused on Java, TypeScript, and AWS. Ideally, it would be great to work on projects that leverage AI or to work in teams building AI-driven products. My core expertise includes: Java · TypeScript · AWS · Spring · REST API · Agile · DevOps (CI/CD, Jenkins, Docker) · Technical Team Leadership