Bohdan Zhyvolup

Senior backend/fullstack engineer, 5+ years. Node.js and TypeScript, PostgreSQL and Firestore, GCP and AWS. I own features end-to-end: design, build, ship, then keep them running in production.

Healthtech - EHR/telehealth platform (current)

• HIPAA multi-region SaaS, 5+ teams: Firebase Cloud Functions, Express REST API, Firestore with a PostgreSQL projection (Pub/Sub, Sequelize), BigQuery

• Optimized a critical legacy module on the largest Firestore collection: queries down from 10-20s, no crashes on complex filters, and fixed silent data loss from a codebase-wide query flaw nobody had spotted

• Designed and shipped a core billing/legal-documents feature around existing legacy code

• Coordinate with partner companies' engineers on the integration API we expose, aligning contracts and resolving cross-org issues

• Review code, proposed improvements to our review process

Fintech/web3 - private asset-management platform

• Main developer on a platform managing 100,000+ USD in client assets: Node.js backend and on-chain integration with complex Solidity contracts via ethers.js, including multi-step transaction chains across contracts

• Decoded and debugged undocumented complex contracts behaviour in Tenderly

• Owned DevOps and security: AWS (Lambda, EC2, ECR), Docker, CI/CD with hardware-key container signing verified at deploy

Internal ERP and finance system

• Built a custom ERP and finance system from scratch in Node.js, TypeScript and Express, replacing spreadsheet workflows

• Designed a normalized complex PostgreSQL database with Flyway migrations; moved 100k+ records out of denormalized spreadsheets with zero downtime via a live sync that let departments keep working

• Worked directly with the people using it - finance, staff, team leads - gathering requirements and building what each needed

• 100% uptime for 2+ years with monitoring and fast incident response; hired, onboarded and mentored developers.