Senior Full Stack Engineer (AWS Microservices & Integrations)

📍 Location: Bristol, UK — predominantly in-house

💼 Employment: Full-Time, Permanent

💰 Salary: £65,000 – £80,000+

📈 Experience: 4+ years operating on AWS with meaningful DevOps ownership

About Us

Narwhal Labs is a fast-growing tech start-up based in Bristol. We are building an AI communications platform at scale, and our engineering team is central to everything we do.

We are looking for a Senior Fullstack Engineer who thrives on ownership, enjoys building reliable systems and wants to help shape the architecture of a product used by real customers in production.

The Role:

We are looking for a Senior Fullstack Engineer to own our microservices platform on AWS. You will build reliable, multi-tenant services and a first-class integration layer spanning messaging, outreach, CRM, billing, analytics and payment systems that powers a SaaS product at scale.

This is an office-based role and candidates must be located in or within commutable distance of Bristol.

Responsibilities:

• Design and build microservices behind API Gateway (REST/HTTP), running on Lambda and containerised workloads on EC2/Fargate
• Model multi-tenant data across DynamoDB and RDS (PostgreSQL), using S3 for object storage and KMS for secrets and encryption
• Build and maintain an integrations layer including OAuth/API-key onboarding, webhook ingestion with idempotency, retries and DLQs, rate-limit mediation, circuit breakers and versioned connector contracts
• Integrate with third-party platforms and payment systems, ensuring secure, reliable and scalable flows for transactions, billing and data exchange
• Design and implement event-driven architecture by publishing and consuming domain events via SQS, SNS and EventBridge, using Step Functions where orchestration is needed
• Maintain observability and reliability through structured logging, metrics and alerts with CloudWatch, trace propagation and error budgets
• Apply security best practices including least-privilege IAM, secret rotation, per-tenant isolation and audit logs
• Define infrastructure as code using AWS SAM and ship via GitHub Actions with automated tests and canary/blue-green deployments
• Define clear API contracts with frontend and AI services, and document runbooks and postmortems

Requirements:

• 4+ years operating on AWS with meaningful DevOps ownership — you have shipped and run production systems
• Hands-on experience with Lambda, EC2/Fargate, API Gateway, S3, DynamoDB, RDS (PostgreSQL), SQS/SNS/EventBridge, CloudWatch and KMS
• Infrastructure as code experience with AWS SAM including templates, pipelines and parameterised stacks
• CI/CD experience with GitHub Actions and automated testing using tools such as Jest/Vitest, Postman/Newman or Pact
• Strong backend development in Node.js/TypeScript (Go or Python also welcome) and solid API design skills across REST, with GraphQL a plus
• Strong data modelling skills including NoSQL vs relational trade-offs, partitioning, indexing and migration strategies
• Proven experience building and consuming webhook-heavy third-party integrations with idempotency and signature verification
• Experience integrating with payment gateways such as Stripe, Adyen or Braintree and handling PCI/DSS-compliant transaction flows

Nice to have:

• Event choreography with Step Functions, schema registries and outbox patterns
• OpenTelemetry/X-Ray tracing and cost and performance tuning for Lambda and RDS
• Experience with Cognito/OIDC, RBAC/ABAC and multi-tenant isolation patterns
• Familiarity with real-time delivery via WebSockets or SSE and streaming responses
• Background in building connector SDKs or integration marketplaces