Senior AI Backend Engineer (AWS / Node.js / TypeScript)

Location: Hybrid from Milton Keynes (3 days/month in office)

Team: Engineers across UK, US, India, Philippines

Reports to: CTO (US)

Works closely with: Head of Engineering (India)

Sign-in notes and initial listings removed for clarity. This description preserves the essential job information and requirements.

Overview

We’re a scrappy, well-funded AI startup turning raw customer feedback into real-time insight for businesses that care about CX. Our 2025 roadmap is ambitious:

• Break apart our Node.js monolith into microservices
• Double our AI-driven workflows
• Harden infra for 100× traffic

Everyone ships. Everyone is on-call. Bureaucracy is nil. Velocity is high.

What Youll Do

• Break up the monolith: Define service boundaries and lead the transition to a microservices architecture. Implement REST + SQS communication, containerized on ECS Fargate. Design services that scale, not snowball.
• Own AI workflow integration: Build and orchestrate AI workflows using OpenAI/Claude APIs today and frameworks like LangChain or similar. Design composable, multi-model pipelines (prompt orchestration, vector DBs, caching, telemetry). Lead the shift toward Bedrock/RAG-native infrastructure.
• Build and scale AI infra: Stand up inference/workflow infra on AWS (Bedrock, SageMaker, or containerized flows). Make AI systems observable, secure, and cost-efficient. You wont be training models from scratch, but youll architect the systems to support them if/when we need to.
• Architect the AI platform: Build infrastructure for experimentation, scale, and optional self-hosting. Define orchestration vs. inference boundaries, expose tracing and prompt history, and keep iteration sane.
• Champion testing and correctness: Enforce robust testing strategies (unit, integration, load). Design testable systems with clear mocks, interface contracts, and fast CI.
• Estimate, scope, deliver: Break complex features into milestones, identify hidden risks, and communicate trade-offs clearly. Youll shape specs as much as you implement them.
• Make it observable: Build first-class telemetry: structured logs, metrics, traces, alerts. Make LLM behavior debuggable and traceable from token usage to prompt mutation.
• Think security first: Handle sensitive customer data with care: PII handling, IAM design, secrets management, rate limiting, GDPR readiness.
• Ship backend code: Work in Node.js/TypeScript with MongoDB (Mongoose), Redis, and job schedulers (cron/EventBridge).
• Keep infra flexible: AWS-first today, modular Terraform for future cloud (GCP) support.
• Mentor & raise the bar: Lead reviews, mentor engineers, and reinforce best practices without slowing velocity. Know when to lean on AI tools and when not to.

Must-Haves

• 8+ years backend engineering; deep experience building distributed systems on AWS with Node.js/TypeScript
• Strong system design skills, especially event-driven/autoscaling architectures
• Production LLM workflow experience (OpenAI, Claude, etc.): you know context windows, token limits, caching, and cost trade-offs
• Workflow orchestration: experience with LangChain, agentic frameworks, or equivalent workflow automation stacks
• Infra-aware mindset: youve deployed and scaled AI workflows/inference via Bedrock, SageMaker, or containers
• MongoDB & Redis tuning/debugging chops
• Terraform & Docker fluency
• Testing mindset with CI/CD experience
• Clear async communicator (writing, docs, code)
• Security & compliance awareness (GDPR/SOC2 basics)
• Proven ability to scope, build, and deliver complex backend features

Nice-to-Haves

• Background in CX, survey, or analytics SaaS
• Bedrock, LangChain, or RAG-native infra exposure
• LLMOps experience (prompt versioning, feedback loops, telemetry)
• GCP infra experience / portability
• React familiarity or empathy for frontend engineers
• Incident response and blameless postmortems

What We Offer

• Competitive salary (band shared at offer stage)
• Standard UK pension
• 20 days holiday + public holidays
• Generous hardware/kit budget
• High autonomy, massive scope
• Personal and professional development budget

Seniority level

• Mid-Senior level

Employment type

• Full-time

Job function

• Information Technology

Industries

• IT Services and IT Consulting

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Milton Keynes, England, United Kingdom