Backend Developer

Cowchain blockchain development company is actively looking for Backend Developer to join our development team.

About us:
Cowchain have successfully completed 150+ projects mainly on EVM-based blockchains such as Ethereum, Polygon, Arbitrum, Base including Coinmarketcap leaders with 180M+ total capitalization and 20M+ daily trading volume in Move2Earn, Play2Earn and DeFi industries.

Key Responsibilities

• Design and develop backend services using TypeScript and NestJS
• Build and maintain event-driven architectures using Kafka and Redis
• Implement and evolve transactional patterns:
  Saga, Idempotency, Ledger, Outbox / Inbox
• Develop blockchain-related logic:
  • Confirmation policies per chain
  • Nonce / sequence management
  • Fee management
  • Transaction de-duplication
  • Backfill and reconciliation processes
• Integrate and maintain multiple blockchain networks:
  Bitcoin, Ethereum, Solana, Tron, TON
• Work with RPC providers (QuickNode, Alchemy, PublicNode, TonOrbs, Blockstream)
• Ensure secure key management using HashiCorp Vault
• Build reliable financial and accounting flows with strong auditability
• Integrate third-party services:
  • Card providers (e.pn, Dauphin)
  • AML provider (Allpass)
  • Centralized exchange (MEXC)
  • Tron energy providers
• Monitor and improve system reliability using Sentry and structured logging
• Participate in architectural decisions and technical planning

Requirements

• 4+ years of experience in backend development
• Strong proficiency in TypeScript and Node.js
• Hands-on experience with NestJS
• Solid understanding of distributed systems
• Experience with Kafka, Redis, and PostgreSQL
• Real-world experience with blockchain integrations
• Understanding of:
  • Transaction lifecycle on different blockchains
  • Confirmations, reorgs, nonces, fees
  • Financial consistency and reconciliation
• Experience with event-driven and fault-tolerant architectures
• Familiarity with security best practices (keys, secrets, access control)
• Ability to work independently and make architectural decisions

Nice to Have

• Experience in FinTech / Crypto / Payments
• Experience designing ledger-based systems
• Familiarity with AML/KYC integrations
• Experience with high-load or mission-critical systems
• Prior work with multi-chain platforms

What We Offer

• Work on a real production crypto-fintech system
• Flexible working schedule, remote work
• Modern tech stack and non-trivial engineering challenges
• Ability to dive into fast-growing blockchain/crypto industry
• Paid vacations, sick leaves
• Strong engineering culture
• 100% friendly/family team