Zdravko Kosanovic, Developer in Belgrade, Serbia
Zdravko is available for hire
Hire Zdravko

Zdravko Kosanovic

Verified Expert  in Engineering

Bio

Zdravko is a senior back-end engineer with over six years of experience in various industries, from telecommunications to fintech. He is proficient in Go and has extensive experience working with cloud providers such as AWS, GCP, and Heroku. Zdravko loves solving problems in a distributed cloud environment and developing and managing microservices.

Portfolio

Rise
Go, Kubernetes, Docker, Redis, PostgreSQL, BigQuery, Amazon Web Services (AWS)...
Rain
Go, PostgreSQL, Redis, Apache Kafka, Heroku, Docker, Microservices, SQL...
Symphony
Go, Protobuf, gRPC, PostgreSQL, Google Cloud Platform (GCP), Kubernetes, Docker...

Experience

  • Docker - 5 years
  • Amazon Web Services (AWS) - 5 years
  • Microservices - 4 years
  • Go - 4 years
  • Redis - 3 years
  • PostgreSQL - 3 years
  • Apache Kafka - 2 years
  • gRPC - 2 years

Availability

Full-time

Preferred Environment

MacOS, GoLand, Docker, GitHub, Amazon Web Services (AWS)

The most amazing...

...thing I've developed with my team is a complete digital platform and infrastructure for one of the biggest telecommunication operators in South America.

Work Experience

Back-end Developer

2022 - 2024
Rise
  • Managed the Rise SSP platform that serves 1+ million requests per second.
  • Maintained Rise adapter on Prebid.js and prebid-server open source libraries.
  • Led cost-reduction projects that cut the operating expenses of the platform by more than 70%.
  • Wrote technical guidelines, held knowledge-sharing sessions, and mentored more junior developers.
Technologies: Go, Kubernetes, Docker, Redis, PostgreSQL, BigQuery, Amazon Web Services (AWS), Amazon RDS, Terraform, Amazon S3 (AWS S3), Amazon EKS, Amazon Elastic Container Service (ECS)

Senior Back-end Engineer

2020 - 2022
Rain
  • Built Rain Pro, an advanced trading platform for experienced cryptocurrency traders.
  • Ensured 99.9% uptime of both Rain Core brokerage and Rain Pro trading platforms.
  • Developed several tools and 3rd-party service integrations to help Rain's growth, marketing, and customer experience teams reduce user churn and speed up growth.
Technologies: Go, PostgreSQL, Redis, Apache Kafka, Heroku, Docker, Microservices, SQL, Distributed Systems, Relational Databases, Back-end, Back-end Development

Software Engineer

2019 - 2020
Symphony
  • Created a digital life insurance platform as part of the Symphony team working as a contractor for a US-based startup.
  • Owned several core services within the microservice architecture after fully integrating into the client's engineering team, handling new features' development, testing, and monitoring.
  • Oversaw the platform's stability and availability, ensuring 99.9% uptime.
Technologies: Go, Protobuf, gRPC, PostgreSQL, Google Cloud Platform (GCP), Kubernetes, Docker, Microservices, SQL, Distributed Systems, Relational Databases, Back-end, Back-end Development, DocuSign

Software Engineer

2018 - 2019
LotusFlare
  • Contributed as part of the server team building LotusFlare's core product, the Digital Network Operator platform, a next-gen software stack for telecom operators.
  • Engaged with the team in designing and developing the platform's features and creating its most successful operator-specific deployment at the time.
  • Oversaw and supported the platform we built from scratch and saw it grow from zero to having over five million daily active users.
Technologies: Scala, Java, Lua, Amazon Web Services (AWS), Apache Kafka, Docker, Redis, Apache Cassandra, ClickHouse, Jenkins, Prometheus, Microservices, Distributed Systems, Back-end, Grafana, Back-end Development, Amazon S3 (AWS S3)

Experience

Rain Pro Platform

https://www.rain.com/en-ae/learn/everything-you-need-to-know-about-rain-pro
Rain Pro is a powerful, advanced trading platform for experienced cryptocurrency traders.

It was built as an evolution of the then-existing, simple, brokerage-based trading model of the Rain crypto exchange.

LotusFlare DNO Platform

https://www.youtube.com/watch?v=_UteggVyoiU
Digital Network Operator (DNO) is a telecommunications platform that lets operators deliver an excellent and fully digital mobile experience. I worked as part of the server engineering team designing and developing the platform from scratch, up to its multiple successful deployments.

Skills

Libraries/APIs

Protobuf, React

Tools

Jenkins, Grafana, BigQuery, Terraform, Amazon EKS, Amazon Elastic Container Service (ECS)

Languages

Go, SQL, Java, JavaScript, C, Scala, Lua, Python

Paradigms

REST, Microservices

Platforms

Docker, Amazon Web Services (AWS), Kubernetes, Apache Kafka, Google Cloud Platform (GCP), Heroku, AWS IoT

Storage

Redis, Relational Databases, PostgreSQL, NoSQL, ClickHouse, Amazon S3 (AWS S3)

Frameworks

gRPC

Other

Distributed Systems, Back-end, Back-end Development, Apache Cassandra, Prometheus, WebSockets, Amazon RDS, DocuSign

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring