Andrei Kavalionak, Developer in Warsaw, Poland
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Andrei Kavalionak

Verified Expert  in Engineering

Software Developer

Warsaw, Poland
Toptal Member Since
April 14, 2021

Andrei is an experienced lead engineer with a demonstrated history of working in the food and beverages, game development, and eCommerce industries. He's skilled in Golang, Java, Python, Docker, Kubernetes, React, and AWS. Andrei is a strong engineering professional with a Bachelor of Science degree from Belarusian State University.


Go, Microservices, Amazon Web Services (AWS), Kubernetes, REST, PostgreSQL...
Banana Whale Studios
Go, Java, Python, JavaScript, React, Tarantool, Elastic, ClickHouse, Ansible...
Go, Amazon Web Services (AWS), Elasticsearch, Apache NiFi, Firebase, Docker...




Preferred Environment

Linux, IntelliJ IDEA, Slack

The most amazing...

...project I've built as a tech and team lead and platform architect is Eatigo, the biggest restaurant reservation platform in Southeast Asia.

Work Experience

Team and Tech Lead Engineer

2020 - PRESENT
  • Developed a new microservice architecture and helped the company transition from a monolith app to microservices.
  • Implemented, tested, and launched a new microservice architecture.
  • Used Jira for feature development tracking and bug tracking.
  • Collaborated with the product team to come up with proper specifications and clarify requirements.
  • Conducted code quality checks and code reviews. Led educational sessions for the remote team.
Technologies: Go, Microservices, Amazon Web Services (AWS), Kubernetes, REST, PostgreSQL, Python, Django, React, Back-end, Postman

Senior Software Engineer

2018 - 2020
Banana Whale Studios
  • Built a new version of a highly scalable and robust back-end system using the microservices architecture.
  • Built a monitoring and alerting system using Prometheus and Grafana.
  • Used Jira for bug tracking and feature development tracking. Used Confluence for documentation.
  • Implemented a full release cycle, including CI/CD pipelines.
Technologies: Go, Java, Python, JavaScript, React, Tarantool, Elastic, ClickHouse, Ansible, Prometheus, NATS, MongoDB, Back-end, REST, Microservices, Postman

Team and Tech Lead Engineer

2016 - 2018
  • Built a new back-end system using microservice architecture and successfully launched.
  • Performed a real-time data migration from a legacy system to a new system.
  • Built a team of engineers from scratch. Prepared and conducted interviews.
  • Created and distributed tasks. Managed development process using Scrum. Conducted code quality checks and reviews.
Technologies: Go, Amazon Web Services (AWS), Elasticsearch, Apache NiFi, Firebase, Docker, Python, Git, Linux, Atlassian, MySQL, Back-end, REST, Microservices, Postman

Senior Software Engineer

2015 - 2016
  • Developed a back-end system facilitating B2B integrations with travel agencies in Singapore.
  • Used Trello for bug tracking and feature development.
  • Initiated and conducted back-end refactoring to align with REST standards and best practices.
Technologies: Go, Docker, Kubernetes, Redis, PostgreSQL, Git, Back-end, REST, Postman

Team Lead

2014 - 2015
IBA Group
  • Developed an internet banking application for Standard Bank of South Africa.
  • Managed a team, controlled and distributed tasks, and performed code reviews.
  • Created technical solutions and helped test and automate testing.
Technologies: Java, Spring, Jira, Confluence, Git, SOAP, REST, Back-end

Software Engineer

2010 - 2014
IBA Group
  • Developed a branch delivery system for Standard Bank of South Africa, used in 800+ bank branches to work with business customers.
  • Investigated bugs and issues and communicated with the team located in South Africa.
  • Contributed to the development of new business functions.
  • Tracked bugs in Bugzilla, used Eclipse as the main development IDE.
Technologies: Java 6, Swing, Java EE 6, Back-end

Eatigo Restaurant Reservation App
Eatigo is a restaurant reservation platform that includes mobile apps and web apps for both restaurant owners and regular users. I served as an architect, team lead, and tech lead. I built the back-end platform and performed the data migration from the legacy system to a new one. This helped the company scale and expand to many countries in the region.
2007 - 2012

Bachelor's Degree in Mathematics and Computer Science

Belarusian State University - Minsk, Belarus


Introduction to TensorFlow

DeepLearning.AI | via Coursera


Machine Learning

Stanford University | via Coursera


Oracle Certified Professional, Java SE 6 Programmer



React, TensorFlow


IntelliJ IDEA, Git, Postman, Slack, Jira, Confluence, Apache NiFi, Atlassian, Elastic, Ansible


Go, Java, Java 6, Python, JavaScript


Linux, Docker, Amazon Web Services (AWS), MacOS, Kubernetes, Firebase, Java SE 6


REST, Microservices


PostgreSQL, MySQL, Tarantool, Redis, Elasticsearch, ClickHouse, MongoDB


Swing, Spring, Django


Back-end, Engineering Software, Cryptography, Java EE 6, SOAP, Prometheus, NATS, Machine Language, Artificial Intelligence (AI), Logistic Regression, Machine Learning

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