valentynkan

Sole backend engineer on the platform: 4 Go microservices from schema design through production, with architecture decisions reviewed together with the tech lead. ● Built the core points service in Go and PostgreSQL: append-only points ledger, task progress tracking, balance and leaderboard projections, REST APIs, Redis caching. ● Built an on-chain activity service indexing ERC-20 transfers and Forge Vault events across Ethereum and Electroneum, with reconciliation workers and transactional outbox processing. ● Implemented blockchain tasks for token holding, swaps and bridge activity, including eligibility rules. ● Built a social verification service validating users' Twitter/X activity, with scheduled sync and retry/backoff. ● Built the monthly airdrop service: pro-rata allocation, Merkle tree generation, proof APIs and on-chain root monitoring. ● Integrated the 1inch CumulativeMerkleDrop contract with Gnosis Safe, keeping signer keys out of the backend. ● Implemented a UUPS-upgradeable Solidity vault for fixed-term ANKR locking and reward distribution, covered by unit, fuzz, invariant and fork tests in Foundry. ● Ran the platform in production: ArgoCD/Kubernetes deployments, migration recovery and incident debugging. ● Wrote an OpenAPI spec and stood up a mock server with fake responses so the frontend could build against the points API before backend endpoints existed. ● Led technical discovery and integration design with an external partner (Kite AI) for a points campaign: wrote the API contract for a partner-side lookup, multi-chain verification flow (Base, Polygon, Avalanche, Tempo, Solana) and GitHub-based developer contribution tracking.

Designed transactional APIs in Go (PostgreSQL row-level locks, context-based authentication, advanced filtering); owned schema migrations (golang-migrate). Built a real-time trading backend: Go core (price streams, decision/risk engine, queues/workers), thin TS adapters over vendor SDKs. Integrated external protocols (Solana DeFi): Meteora DLMM for CLMM liquidity and Drift perps for hedging via typed endpoints. Built a signal-driven trading bot tracking Solana DCA activity via Jupiter in real time, with configurable filters and automated futures execution, stop-loss/take-profit risk management, and Telegram notifications; wound down after a profitability analysis showed the strategy wasn't viable at target scale. Implemented reliability mechanisms including structured logging, retries with backoff, idempotency, and Telegram-based operational alerts. Developed automated tests using Testify/mock, with typed validation contracts using Zod and environment-driven configuration.