Software Engineer (Indexer Focus)

Duties

• Design, build, and operate the Indexer’s components in Rust — the chain indexer, the wallet indexer, the SPO indexer (Cardano partner-chain data), and the GraphQL API — keeping the architecture modular and maintainable.
• Build and maintain the data pipeline that fetches blocks and transactions from the Midnight node via subxt, handling finalized-block tracking, gap backfilling, and continuous real-time indexing.
• Design efficient schemas and queries across PostgreSQL (cloud) and SQLite (standalone), and keep latency and throughput healthy as the chain grows.
• Evolve the GraphQL API — queries, mutations, and real-time subscriptions over WebSockets — with care for the wallet model: secure sessions and correct handling of shielded data.
• Write and maintain unit, integration, and end-to-end tests; treat reliability and correctness as first-class concerns.
• Own operational quality for the service: observability, containerised deployment (Docker), and incident response.
• Participate in code reviews and technical design discussions, and collaborate closely with the node, ledger, wallet, and security teams — contributing to those components as you ramp up.
• Keep current with developments in Rust and blockchain technology, and apply them to improve the platform.

Key Competencies

Core Requirements (the Indexer)

• Strong, idiomatic Rust — including async/await (tokio) and a solid grasp of concurrency.
• Backend / data-systems experience — you have built and operated high-performance services or data pipelines in production.
• Databases — practical experience with PostgreSQL and/or SQLite: schema design, query optimisation, and reasoning about performance.
• API design — designing and evolving service APIs; GraphQL experience is a big plus.
• Computer-science fundamentals — sound on data structures, algorithms, and concurrency.
• Engineering discipline — comfortable with rigorous testing, code review, and clear technical communication.
• Remote collaboration — effective working asynchronously across time zones.

Valued — enables you to contribute across the stack

These are not hard requirements. A strong async-Rust engineer can ramp on the blockchain specifics; the items below let you reach beyond the Indexer sooner.

• Substrate / Polkadot ecosystem — especially subxt, plus familiarity with pallets and runtime development.
• Blockchain core concepts — consensus mechanisms, cryptography, and transaction/state models.
• Applied cryptography or zero-knowledge — interest in the Ledger’s transaction structure, state, and proving systems.
• WASM — compiling Rust to WebAssembly.
• Cardano / partner chains — Midnight runs as a Cardano partner chain, so this context is useful.

Education / Experience

• At least 3 years of experience in software development, with at least 2 years in the Rust programming language.
• Strong understanding of computer science fundamentals, including algorithms and data structures.
• Experience in developing and maintaining high-performance systems in Rust.
• Experience with blockchain technology is a plus.
• Experience in remote work and collaboration across different time zones.
• Experience working in scale-ups.