Senior Backend Engineer

Senior Backend Engineer

About the Role

We're hiring Senior Backend Engineers to own backend product development end-to-end from APIs and data models to the systems that orchestrate AI agents, run asynchronous workloads, and power knowledge retrieval.

Our backend is built with TypeScript/NestJS and Python, running on PostgreSQL and AWS. You'll work across both.

Experience: 8–10 years building production-grade backend systems.

What You'll Do

• Shape ambiguous product problems into technical designs. Work directly with product and design to pressure-test requirements, propose alternatives, and choose the simplest solution that actually solves the user's problem.
• Own backend features end-to-end — including API design, data modelling, implementation, rollout, and production operations. You ship it and you run it.
• Work across our AI and agent systems, including prompt and context design, tool execution, multi-provider LLM integrations, and streaming responses.
• Design and operate resilient asynchronous systems, including queues, retries, idempotency, cancellation, observability, and fault tolerance. Our workloads are long-running and failure-prone by nature; correctness under partial failure is the job.
• Build ingestion pipelines that turn diverse content into structured, searchable, and retrievable knowledge.
• Build integration layers against third-party platforms, normalising inconsistent APIs, authentication models, and content formats behind stable internal contracts.
• Design schemas and run live migrations against production data without downtime.
• Improve reliability, performance, and observability across production systems.

Must Have

• Strong production experience with Node.js and TypeScript, ideally with NestJS. Experience with Express or Fastify is also relevant.
• Strong production experience with Python, including asynchronous programming. Experience with FastAPI, Django, Flask, asyncio, Celery, or equivalent technologies.
• A track record of taking products from zero to production, rather than only extending existing systems.
• Deep relational database expertise, including schema and data modelling, indexing, query performance, and live-data migrations. PostgreSQL experience is preferred.
• Real-world experience with queue-based and event-driven architectures, with a strong understanding of at-least-once delivery, retries, idempotency, poison messages, and partial-failure recovery.
• Production experience with AWS, including S3, SQS, Lambda, CloudFront, Cognito (or equivalent identity/IAM services), and KMS.
• A solid understanding of design patterns, scalable architecture, and clean, testable code — along with the judgement to know when a pattern isn't worth using.
• Designs from the problem, not the ticket. You ask who the user is and what breaks for them before choosing a data model; you push back on requirements that don't hold up; and you design APIs that can support the next three features rather than only the current one.
• Clear written and spoken English, along with the communication habits required to work effectively in a distributed, fast-moving team.

Nice to Have

• Hands-on production experience with LLM providers such as Anthropic, OpenAI, or similar, including streaming, tool calling, structured output, retries, and context-window management.
• Experience with job orchestration and background processing systems, including schedulers, workflow engines, long-running job state machines, and the operational aspects of running them, such as visibility, replay, and dead-letter handling.
• Experience with vector databases and retrieval systems at scale, including chunking strategies, embedding pipelines, hybrid search, and relevance tuning.
• Experience building real-time systems, including WebSockets, server-sent events, and connection authentication.
• Experience with multi-tenant SaaS, OAuth, and third-party credential management.
• Experience with Docker, CI/CD, and infrastructure-as-code.
• Experience publishing and maintaining npm or PyPI packages, with disciplined semantic versioning (semver) and dependency management.
• Working knowledge of React, TypeScript, and Next.js to contribute across the stack when it helps unblock delivery.le & responsibilities

Preferred candidate profile