Nikita
Zakharenko.

• ClickHouse analytics: 10B+ rows, ~1 TB, API response ≤300 ms.
• Optimized a 350 GB PostgreSQL table with recurring deadlocks.
• Designed and built 2 high-load services from scratch, including complex business logic.
• REST and gRPC APIs, RBAC and WebSocket notifications for an employee support platform.
• Rolled out Jaeger and Pyroscope; built Grafana dashboards and CSAT, RSA and SLA metrics.
• PostgreSQL-to-ClickHouse migrations. Integrated a proprietary LLM into an employee support chat.
• 24/7 incident response, code reviews, unit and integration tests. Worked directly with product owners and C-level stakeholders.

Go · PostgreSQL · ClickHouse · Kafka · gRPC

• ~200 paying customers. 3 servers. ~4.5 TB of traffic per day.
• Owned engineering, infrastructure, subscription payments, customer support and legal matters.
• Built the service on VLESS and 3x-ui; managed the product from first commit to day-to-day operations.

VLESS · 3x-ui · Infrastructure

• Built core alerting services with Go and Node.js.
• SIP terminal grouping and emergency notifications.
• Configured test and production environments. Wrote unit and e2e tests and introduced TDD on a project with no QA.

Go · Node.js · PostgreSQL · MongoDB