Aaron Lewis
Software Engineer
Building distributed systems, cloud-native platforms and event-driven architectures.
Software engineer with 6+ years of experience designing and delivering distributed, cloud-native platforms across the public sector, l&d and energy industries. Experienced building event-driven systems, including financial decisioning services, home energy optimisation platforms and secure third-party integrations. Strong background in developing resilient, scalable services operating under regulatory, audit and availability requirements, with a particular interest in fintech, payments and large-scale backend systems.
Professional Experience
Software Development Consultant
- ▸Designed and delivered backend services supporting financial eligibility and entitlement decisions, where system correctness directly influenced payment outcomes for citizens.
- ▸Designed and built event-driven microservices using Java, Kotlin, Spring Boot and WebFlux, supporting high-volume eligibility and case-management workflows under strict audit and governance requirements.
- ▸Designed secure API platforms integrating internal and third-party services, implementing OAuth2, authentication, authorisation and encryption controls for sensitive financial data.
- ▸Designed and delivered event-driven AWS architectures using SNS, SQS, EventBridge and Step Functions, processing large quantities of eligibility and entitlement events while improving system resilience, traceability and auditability.
- ▸Contributed to AWS infrastructure using Terraform, embedding security, observability and operational controls as standard.
- ▸Mentored engineers, led architectural discussions and contributed to technical decision-making across multiple delivery teams. Responsible for epic planning & weekly backlog refinement.
Swarm Energy Limited
- ▸Designed and implemented Kotlin and Spring WebFlux services responsible for optimising residential battery charging schedules using dynamic energy tariffs, device telemetry and household consumption data.
- ▸Built event-driven workflows using SNS, SQS, EventBridge and AWS Lambda to execute daily optimisation processes and automate charging / offloading decisions across connected energy devices.
- ▸Implemented secure authentication, key management and encryption using Auth0, Spring Security and AWS KMS to protect customer and provider credentials.
- ▸Built resilient ingestion pipelines integrating third-party energy providers including Octopus Energy, using API Gateway, EventBridge and Lambda to process tariff and consumption data.
- ▸Contributed to AWS infrastructure with Terraform, supporting scalable, fault-tolerant production systems and automated deployment pipelines.
Department For Work And Pensions
- ▸Designed and delivered backend services supporting financial eligibility, entitlement and case-management workflows, replacing legacy platforms with modern cloud-native microservices.
- ▸Built rules-driven decisioning APIs in Java and JavaScript responsible for determining benefit eligibility and entitlement outcomes under strict governance and regulatory controls.
- ▸Migrated critical workflows from monolithic systems to event-driven architectures, improving scalability, maintainability, and operational resilience.
- ▸Provided technical leadership during delivery-critical phases, including architectural ownership, risk management and cross-team coordination.
- ▸Contributed to a programme shortlisted for government awards, helping secure follow-on delivery work and subsequent programme investment.
Software Engineer
- ▸Contributed to the development of a flagship multi-tenant learning management platform, supporting weekly production releases for enterprise and educational customers.
- ▸Delivered backend and frontend functionality across the platform, balancing rapid feature delivery with maintainability, testing and long-term technical quality, serving thousands of learners.
- ▸Collaborated closely with QA, product and design teams to deliver customer-facing features and continuously improve the user experience.
- ▸Conducted technical spikes and proof-of-concept work to evaluate architectural approaches and inform engineering decisions.
Software Engineer Intern
- ▸Contributed to the modernisation of the GOV.UK digital tachograph service, helping migrate functionality from legacy applications to modern microservice-based architectures.
- ▸Developed backend and frontend components within a cross-functional agile team, delivering new services using TDD and modern software engineering practices.
- ▸Participated in stakeholder demonstrations and technical walkthroughs, communicating technical solutions and system behaviour to both technical and non-technical audiences.
Technical Expertise
Backend & APIs
JavaKotlinSpring BootSpring WebFluxREST APIsOAuth2 / OIDC
Distributed Systems & Messaging
KafkaSNSSQSEventBridgeMicroservicesEvent-Driven Architecture
Cloud & Infrastructure
AWSLambdaAPI GatewayTerraformDockerRedisInfrastructure as Code
Security & Data
Authentication & AuthorisationSecure API DesignAWS KMSPostgreSQLMongoDB
Engineering Practices
TDDBDDCI/CDObservabilityRegulated Environments
Frontend
TypeScriptJavaScriptReactNode.jsCSS
Accolades & Certifications
AWS Certified Cloud Practitioner (CLF-C02)
LFC131: Green Software for Practitioners
Excellence Scholarship for Education
DWP Project Award Nomination
Education
BSc Computer Science, First-Class Honours (80%)
Swansea University