Senior Backend Engineer (Node.js / TypeScript)

Responsibilities

Market data: ingest vendor feeds, normalize instruments and symbology, and fan out to web and mobile clients over WebSockets (subscription management, snapshot + delta, conflation and throttling, slow-consumer handling, reconnect and resync); enforce entitlements (real-time vs. delayed, professional vs. non-professional).
Order management: build the integration layer on top of the clearing firm's REST and FIX APIs order gateway (validation, pre-trade checks, idempotent submission), order state driven by provider events, positions, realized and unrealized P&L, reconciliation against snapshots and the ledger.
Reliable ingestion of provider webhooks and event streams: signature verification, deduplication, out-of-order handling, gap detection, replay.
Authentication and session management, account lifecycle, entitlements, and billing hooks.
Identify gaps in vendor APIs and propose solutions (build, work around, or escalate to the vendor). Design for graceful degradation when upstream feeds are unavailable.

Requirements

5+ years of backend development with a focus on distributed, event-driven systems; 3+ in Node.js / TypeScript, including the runtime under load (event loop, stream backpressure, memory/GC, scaling stateful connections).
Has built and operated a high fan-out real-time system serving many concurrent clients and can describe it in numbers (connections, messages per second, p99 latency).
Practical understanding of message ordering, duplicate delivery, idempotency, retries, backpressure, replay, and failure recovery.
Experience running production systems that handle financial transactions; experience with monitoring, structured logging, tracing, and incident investigation.
Experience with AWS (containers, IAM, managed messaging/streaming) and Redis; infrastructure-as-code.
Strong automated-testing practices (unit, integration, end-to-end).
Occasional traveling to the USA might be needed.

Nice to have

Brokerage, clearing, custody, or market-data provider integrations; knowledge of equity and options order lifecycles (submission, partial fills, cancel/replace, rejection).
FIX, financial instrument symbology, exchange connectivity.
PostgreSQL, Redis, and a time-series or analytical store.
Systems handling monetary values, audit trails, reconciliation, regulatory requirements.
Futures, crypto, or prediction-market platforms.