Dmytro – Golang, Kubernetes, Terraform

Infrastructure management tools for blockchain networks running in Kubernetes. The work covered three projects: a SaaS for deploying and monitoring blockchain services in Kubernetes, a Kubernetes operator for running Besu nodes across clusters of different clients, and infrastructure management for Canton blockchain validators.

• Built a SaaS from scratch with Temporal workers to deploy, delete and upgrade services in Kubernetes.
• Replaced self-made workers with Temporal.
• Integrated with the Kubernetes API to create PostgreSQL, RabbitMQ and secrets, and with Prometheus to track service status.
• Calculated infrastructure cost with OpenCost and kube-state-metrics.
• As Team Lead, turned verbal requirements into technical specs and Jira tasks, managed releases and ran team meetings.
• Built a Kubernetes operator from scratch to run Besu blockchain nodes.
• Connected blockchain nodes in private networks of different clients via VPN.
• Created and maintained Kubernetes CRDs and reconcilers in Java.
• Built a standalone backup and restore solution for blockchain validators.
• Led the second version of the platform and an on-prem Kubernetes cluster deployment.
• Added ArgoCD and a test environment.
• Added automated pull request testing on a dev cluster and wrote smoke tests from scratch.
• Improved CI/CD so the same application can run in different namespaces of one cluster.
• Set up an AI-assisted development workflow.

Backend for a financial institution, built as a set of microservices. I worked in the users and reports squad, which handled user statistics and reporting data.

• Developed gRPC API handlers and Kafka workers.
• Added Kafka handlers that collected user statistics into a database.
• Created a new microservice with an RPC API that returned currency rates by organisation, with rates read from a Kafka topic.
• Created middleware for Kafka handlers that stored an idempotency key in the database and skipped duplicate messages.
• Used Kibana and Jaeger to troubleshoot issues in a distributed system.

A multi-tenant crypto-currency wallet service. Clients used it to manage deposits and withdrawals in ETH and BTC, set currency rates and configure validation rules. The service had separate admin and client dashboards.

• Built the admin dashboard REST API (OpenAPI schema) from scratch.
• Built the client dashboard REST API (OpenAPI schema) from scratch.
• Implemented multi-tenancy using a tenant ID in each database table
• Added support for custom currency rates.
• Added client-configured validation rules to the deposit and withdrawal flow.
• Built a background worker that listened to ETH and BTC blockchains via RPC and saved incoming wallet transactions to the database.
• Built a background worker that processed deposits and withdrawals.
• Integrated with a currency exchange provider.