Case studies

Development and evolution of a payment system core with integrations to the ГИС ГМП state system and acquiring providers.

• 20,000+ successful transactions a day at 99.99% uptime;
• payment initialization and processing optimization: +~10% conversion of successful payments, −15% average transaction processing time;
• idempotency and retry in integrations: −25% erroneous and fraudulent operations (per the security team);
• async processing via RabbitMQ (notifications, reconciliations) — zero financial losses on non-critical paths;
• Web + Mobile API unification: −60% code duplication, a new endpoint 2× faster;
• ClickHouse for analytics: daily financial reports in 3–5 minutes instead of several hours.

A platform connecting customers and carriers: competitive requests, document flow, reverse auctions.

• High Availability architecture with horizontal scaling: stable at +100% peak load without degradation of critical operations;
• RBAC with hierarchy down to the department level: safe data isolation for hundreds of client companies;
• hybrid sync/async processing (RabbitMQ) for documents and reports — no UI timeouts, guaranteed background execution;
• SSE — real-time reverse auctions; REST + GraphQL for integrations;
• as team lead: a backend team of 5 developers, 85–90% sprint predictability, 20% capacity for tech debt, −40% production incidents.

• City Business School (2015–2017): B2C platform for 100,000+ users — monolith decomposition, multi-level caching, APM from scratch, async generation of large reports.
• HotelsPro / Kakdoma (2011–2015): a PMS from scratch — hotel portfolio growth from 10 to 150+ without a full rewrite; billing with 5+ providers and acquirer rotation; releases from 1/month to 2/week after CI/CD.
• GMBT / Atelgo (2006–2010): an OMS handling 1,000+ orders a day, a partner program for 50+ partners, security audit per OWASP Top 10.