Senior Backend Developer (Staking)

About the Project
GraphDEX is building infrastructure for on-chain data indexing, trading automation, and DeFi integrations.

Our next milestone is launching the Earn (Staking) module: a service offering fixed investment plans with integration into Solana and WhiteBIT API, featuring deposit management, reward distribution, and liquidity control.

We are looking for a Senior/Tech Lead engineer to lead the backend development of this direction.

Responsibilities

• Design and maintain backend architecture for GraphDEX products, including API development, data processing pipelines, and integrations.
• Develop and maintain services for managing staking plans, deposits, reward calculations, and liquidity tracking.
• Integrate with blockchain networks and external APIs (Solana SDK, WhiteBIT API, GraphQL subgraphs).
• Build and optimize event-driven architecture: ensuring idempotency, transaction reliability, retries, and dead-letter queues.
• Design and optimize database schemas (PostgreSQL): indexes, partitioning, JSONB, query performance, migrations.
• Ensure system performance, scalability, and security, including safe handling of cryptographic keys.
• Implement monitoring and observability: metrics, logs, traces (Prometheus, Grafana, OpenTelemetry).
• Write clean, testable, and well-documented code; participate in code reviews and architectural discussions.
• Collaborate closely with frontend, SRE, and QA teams to ensure smooth development and release cycles.

• Lead and mentor a small team of backend engineers, ensuring best practices in code quality and engineering processes.

   

Requirements

• 5–8+ years of backend development experience.
• 2–3+ years of experience in blockchain/DeFi (EVM/Solana, smart contracts, on-chain data).
• Proven leadership experience (Tech Lead/Team Lead) with planning, code review, and prioritization.
• Strong skills in Python (FastAPI/Starlette, asyncio, SQLAlchemy, Alembic) and/or Rust (async/Tokio).
• Solid database expertise with PostgreSQL: complex schema design, indexing, partitioning, performance optimization.
• Experience with message queues (RabbitMQ/AMQP) and event-driven systems.
• Familiarity with Subgraph (The Graph), including schema design and indexer optimization.
• Strong understanding of system observability, performance tuning, and reliability (SLO/SLI).

• Knowledge of backend security practices: access control, data validation, secure key storage (Vault/KMS/HSM).

   

Nice to Have

• Production-level experience with Rust (async/Tokio, tracing, profiling).
• Experience with Go (CLI tools or microservices).
• Building ETL pipelines for on-chain data, DWH (ClickHouse/BigQuery).
• Understanding of L2 solutions (Optimism, Arbitrum), cross-chain bridges.
• Experience with MEV, mempool, and gas optimization.
• Hands-on with Web3 developer tools (Foundry, Hardhat, Ethers.js, web3.py).

• Experience with Kubernetes, Terraform/Ansible, advanced monitoring/alerting setups.

   

We Offer

• Opportunity to develop a brand-new DeFi product within GraphDEX.
• Influence over the architecture and strategy of the staking module.
• A small but strong engineering team.
• Competitive USD-based compensation + stock options.
• Remote work format and flexible schedule.