Senior Full Stack Engineer (AWS Microservices & Integrations)

<p> <strong>Location:</strong> Bristol, UK — predominantly in-house</p><p> <strong>Employment:</strong> Full-Time, Permanent</p><p> <strong>Salary:</strong> £65,000 – £80,000+</p><p> <strong>Experience:</strong> 4+ years operating on AWS with meaningful DevOps ownership</p><p><br><br>If you think you are the right match for the following opportunity, apply after reading the complete description.<br></p><p><strong>About Us</strong></p><p>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.</p><p>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.</p><p><br></p><p><strong>The Role:</strong></p><p>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.</p><p>This is an office-based role and candidates must be located in or within commutable distance of Bristol.</p><p><br></p><p><strong>Responsibilities:</strong></p><ul><li>Design and build microservices behind API Gateway (REST/HTTP), running on Lambda and containerised workloads on EC2/Fargate</li><li>Model multi-tenant data across DynamoDB and RDS (PostgreSQL), using S3 for object storage and KMS for secrets and encryption</li><li>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</li><li>Integrate with third-party platforms and payment systems, ensuring secure, reliable and scalable flows for transactions, billing and data exchange</li><li>Design and implement event-driven architecture by publishing and consuming domain events via SQS, SNS and EventBridge, using Step Functions where orchestration is needed</li><li>Maintain observability and reliability through structured logging, metrics and alerts with CloudWatch, trace propagation and error budgets</li><li>Apply security best practices including least-privilege IAM, secret rotation, per-tenant isolation and audit logs</li><li>Define infrastructure as code using AWS SAM and ship via GitHub Actions with automated tests and canary/blue-green deployments</li><li>Define clear API contracts with frontend and AI services, and document runbooks and postmortems</li></ul><p><br></p><p><strong>Requirements:</strong></p><ul><li>4+ years operating on AWS with meaningful DevOps ownership — you have shipped and run production systems</li><li>Hands-on experience with Lambda, EC2/Fargate, API Gateway, S3, DynamoDB, RDS (PostgreSQL), SQS/SNS/EventBridge, CloudWatch and KMS</li><li>Infrastructure as code experience with AWS SAM including templates, pipelines and parameterised stacks</li><li>CI/CD experience with GitHub Actions and automated testing using tools such as Jest/Vitest, Postman/Newman or Pact</li><li>Strong xwzovoh backend development in Node.js/TypeScript (Go or Python also welcome) and solid API design skills across REST, with GraphQL a plus</li><li>Strong data modelling skills including NoSQL vs relational trade-offs, partitioning, indexing and migration strategies</li><li>Proven experience building and consuming webhook-heavy third-party integrations with idempotency and signature verification</li><li>Experience integrating with payment gateways such as Stripe, Adyen or Braintree and handling PCI/DSS-compliant transaction flows</li></ul><p><br></p><p><strong>Nice to have:</strong></p><ul><li>Event choreography with Step Functions, schema registries and outbox patterns</li><li>OpenTelemetry/X-Ray tracing and cost and performance tuning for Lambda and RDS</li><li>Experience with Cognito/OIDC, RBAC/ABAC and multi-tenant isolation patterns</li><li>Familiarity with real-time delivery via WebSockets or SSE and streaming responses</li><li>Background in building connector SDKs or integration marketplaces</li></ul>