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Ivan Kulagin photo Ivan Kulagin
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Ivan Kulagin

My name is Ivan, and I am a backend developer since 2012. Since then I selected the stack of different lovely technologies I use daily in my work: Ruby language, TypeScript/Javascript, testing, refactoring, microservices, devops, data parsing/manipulation, APIs design, and of course trendy AI & Automation workflow building (which is actually no/less-code backend development).

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Skymond mobile Op

Development of Online Charging System (OCS) for virtual mobile operator serving the Caribbean region. This project provided extensive experience in telecommunications infrastructure, high-load systems architecture, and integration with major mobile operators. The system handled real-time billing and policy management for mobile subscribers across multiple carriers.

Key achievements and responsibilities:

  • Implemented high-performance Diameter protocol server for real-time charging and policy control
  • Designed and deployed cloud infrastructure on GCP using Terraform
  • Built distributed telecom system using Ruby on Rails and lightweight Ruby microservices
  • Integrated with major Caribbean mobile operators’ infrastructure (all using Juniper hardware)
  • Developed automated SFTP data synchronization service for customer data exchange
  • Implemented real-time CDR (Call Detail Records) processing and billing pipeline
  • Designed and implemented fault-tolerant database cluster using PostgreSQL
  • Developed API gateway for third-party service integrations and partner access
  • Built comprehensive reporting and analytics dashboard for business intelligence

One of my favorite jobs: networking, protocols (I heard nothing about Diameter protocol till then), high-load, focused services, lots of data. And yes, all that with Ruby under the hood. Nowadays, of course, I’d use Rust for all that, but Ruby did the job great.

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