Graphdex.io

We work at the intersection of blockchain technologies, high-load systems, and next-generation financial instruments. Our products are data indexing, trading automation, and DeFi integrations.
Stack: Python, Rust, TypeScript, PostgreSQL, RabbitMQ, Docker, Web3/EVM.

Responsibilities

• Develop and maintain backend services in Python (FastAPI / aiohttp), write async code, and integrate services with PostgreSQL and RabbitMQ.
• Implement message handlers (consumers/producers), add idempotency and retry logic.
• Write unit/integration tests, help introduce CI plans, and ensure release stability.
• Participate in creating APIs (OpenAPI), documentation, and database migrations (alembic).

• Work closely with the Platform/DevOps team on configuring staging/production environments and monitoring.

   

Requirements

• 4 years of experience in Python/FastAPI development.
• Practical experience with async Python (asyncio/aiohttp/aiopg/asyncpg) or solid knowledge of WSGI/ASGI stacks (FastAPI, Starlette).
• Experience working with PostgreSQL (SQL, migrations), basic understanding of transactions and indexing.
• Experience working with message queue systems (RabbitMQ, Kafka, or similar) — implementing consumers/producers.
• Test writing skills (pytest), familiarity with CI (GitHub Actions/GitLab CI).

• Ability to read other people’s code, create PRs with clear descriptions, and conduct code review.

   

Nice to have (plus)

• Experience with Docker and Kubernetes (deployment, helm charts).
• Familiarity with OpenTelemetry/Prometheus/Grafana and logging (structured logging).
• Experience integrating with external APIs (OAuth/JWT, webhooks).

• Knowledge of Rust/Go or understanding of microservice architecture — will be a plus.

   

What we offer

• Hybrid/remote work, competitive salary, optional participation in the option pool.
• Work with interesting Web3/DeFi integrations, opportunity to grow into Tech Lead.
• A strong technical team, code reviews, architectural discussions.
• Infrastructure and processes: CI/CD, monitoring, staging environments.

About us
We are building a high-load decentralized platform at the intersection of blockchain and fintech: on-chain data indexing, trading automation, and integrations with DeFi and Web3.

Responsibilities

• Design and develop backend architecture: APIs, queues, indexers, bots/workers for on-chain event processing.
• Develop event-driven architecture with idempotency, exactly-once delivery (transactions + deduplication), outbox/inbox, retries, and DLQ.
• Integrate with Web3/EVM/Solana: read and process events, interact with smart contracts, manage nonces, handle reorg/finality, and multi-chain transactions.
• Work with Subgraph (The Graph): design schemas, implement TypeScript mappings, and optimize blockchain data indexing.
• Develop DeFi integrations: Uniswap v2/v3, AMM pools, pricing, liquidity, routing, slippage/MEV resistance.
• Optimize performance: profile hot paths, migrate critical components to Rust, ensure async/tokio efficiency, manage backpressure.
• Ensure observability and reliability: metrics/traces/logs (Prometheus, Grafana, OpenTelemetry), SLO/SLI tracking, degradation and fallback mechanisms.

• Provide leadership: define technical vision, mentor developers, conduct code reviews, prioritize backlog, and introduce best engineering practices.

   

Requirements

• 5+ years of commercial backend development experience.
• 3+ years in blockchain/DeFi (EVM, Solana, on-chain data, smart contracts, integrations).
• 2+ years in a Tech Lead or Team Lead role.
• Strong Rust experience: async/tokio, network programming, performance profiling.
• Proficiency with queues/events: RabbitMQ/AMQP, delivery guarantees, retries, DLQ, message contracts.
• Experience with Blockchain/DeFi: ABI, events, integration with Solidity and Solana programs, multi-chain interactions.

• Knowledge of Subgraph (The Graph): schema design, mappings, indexing optimization.

   

Nice to have

• Production experience with Rust (tokio, async, tracing), low-level performance profiling.
• Knowledge of Go (CLI/tools), ETL pipelines for on-chain data, DWH (ClickHouse/BigQuery).
• Experience with Layer 2 (Optimism, Arbitrum), cross-chain bridges/protocols.
• Experience with MEV, mempool monitoring, gas optimization.
• Familiarity with Web3 tools: Foundry, Hardhat, Ethers.js, web3.js, Anchor (Solana).