Top 1 mobile payment app in Japan with more than 60M users. The app is designed in the superapp manner and contains lots of miniapps covering wide range of user needs. I worked on building high performing and scalable platform for payment linked coupon promotion platform for the organized and un-organized merchants.
Highlights

• Maintained and developed high-loaded micro-services with 4K daily peak RPS and 1K MPS
• Implemented Clean Architecture approach that improved code readability, maintainability and testability. Also it reduced the number of bugs and decreased the feature delivery time.
• Took major part in code + infrastructure migration project: seamless migration of outsourced micro-services to the company's infrastructure complying with internal code standards/libraries/dev and CI/CD flows. The migration also implied complete code refactoring with respect to the clean code architecture.
• Improved team's knowledge by keeping knowledge-sharing sessions.

The company collects information about network and session(game, video, VoIP) quality from mobile devices, aggregates it and provides analytical products for mobile operators to monitor their network state, searching places with bad coverage, planning network modernization and expansion.
Highlights

• Designed and implemented a backend system for a new product, which unite the functionality of existing ones.
  • - Proposed and proved the necessity to migrate the storage layer from Cassandra to Clickhouse to achieve the required performance and functionality. Developed a new data model
  • - Designed and implemented a complex API which allows building custom analytical reports using complicated filtering, grouping, ordering
• Embed Micronaut as a DI framework (no DI framework had been used before), which made the system more testable and less coupled.

Responsibilities

• Build a backend for a new product
• Conduct technical interviews for candidates
• Code review

Virtual telecom operator in UK.
Highlights

• Created cloud-based micro-service platform from scratch using AWS cloud with no experience in the latter.
• Seamlessly migrated existing users from the prototype solution to the platform

Responsibilities

• Make almost all technical decisions concerning the cloud platform, including:
  • - architecture design
  • - development, testing and deployment processes
  • - set up logging and monitoring
• Maintain production, stage and testing environments
• Mentor other developers
• Tier 2, 3 customer support

Took a major part in creating a distributed voice\face recognition platform. The platform was a middle layer between business applications and different face\voice SDK, developed by R&D department.
Highlights

• Creation of the most complicated platform services
  • - Configuration Service - a separate configuration server with a web interface, which controls the configuration of the whole platform and allows to monitor and configure services on-the-fly
  • - Load Balancer - an internal service, which controls face/voice models cache distribution among processing engines and performs query routing. The service lets big identification queries (1 x 100M faces) complete with minimum overhead
• Implementation of custom deployment tools for the team, which allowed developers to test their code on test environments much faster (deployment time decreased from an hour to a couple of minutes)

Responsibilities

• Technical design/review/implementation of new services and features
• Integration with new SDK's and systems
• Search and optimize system's bottle-necks
• Advise DevOps team on automated build and deployment

Created a full-stack solution for a hotel self-check-in kiosk. The system consisted of

• back-end server, integrated with the kiosk and the hotel reservation system
• web back-office for the hotel's receptionists

Carried out the full development cycle, from business requirements analysis until the system deployment.