Senior Full Stack Engineer

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., * Lead the design and implementation of full-stack web applications using technologies such as JavaScript, Java, C#, Python, Ruby on Rails, C++, and .NET.

• Develop and maintain RESTful APIs and integrate third-party services to enhance application functionality.
• Collaborate with cross-functional teams to gather requirements and translate them into technical specifications.
• Utilise version control systems including GitHub, SVN, and Git for source code management.
• Ensure code quality through code reviews, testing, and adherence to best practices in software development.
• Optimise applications for performance, scalability, and security within cloud environments such as AWS and Azure.
• Maintain documentation related to system architecture, API specifications, and deployment procedures.
• Support continuous integration/continuous deployment (CI/CD) pipelines to streamline release processes.
• Troubleshoot and resolve complex technical issues across multiple platforms including Linux environments.
• Stay updated with emerging trends in software development and incorporate relevant technologies into projects.

• 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

Desirable

• 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