Senior Kotlin Engineer - Contract at Lendable

Worked on the Lendable Pensions Platform to onboard, transfer, and maintain customers’ pension portfolios via integration with the WealthKernel API. The project extends an existing lending platform to support pension services for existing customers before wider UK rollout. Backend services are implemented in Kotlin with an API layer built using Http4k, using Postgres for storage and RabbitMQ for messaging. Communication is primarily via GraphQL using a CQRS pattern. Deployment and observability include Terraform, Kubernetes, ArgoCD, and Datadog. Architecture uses hexagonal principles with proxy/decorator patterns for generic interfaces and transactional action pipelines. Feature flagging is implemented with GrowthBook; ways of working include Kanban with weekly planning and demos.

Senior Java Engineer - Contract at Engine by Starling

Contributed to customer management capabilities in a B2B banking services platform serving financial institutions globally. Participated in new client feature delivery, including association between Person and Business with Initial Account Product offerings, PDF support for person documents via API spec updates, and audit updates for communication consent preferences. The platform consists of domain microservices grouped by banking features (onboarding, payments, customer service, reporting). CI/CD uses Teamcity + GitHub actions with AWS services. Backend is primarily Java with JAX-RS, Guice DI, and Postgres persistence.

Senior Kotlin Engineer - Contract at The Hong Kong Jockey Club

Worked on a cross-platform NBA basketball betting application (“Alley-oop”) built with React Native for Android and iOS. Supported backend microservices including wallet and player account management, deposit/withdrawal flows, and integrations with financial service providers. Delivered Kotlin-based backend services using Spring Boot on AWS (RDS, ElastiCache). Contributed to CI/CD integration with Kubernetes and Helm, and implemented testing layers (functional tests and smoke/service tests) to automate deployment. Added Datadog and SonarQube integrations for code quality and observability.

Senior Kotlin Developer - Contract at HeyCar

Contributed to core platform capabilities including search indexing and content ingestion automation. Built and maintained Elastic Search indexing/mapping used by front-end and client APIs, with Kotlin and Spring Boot deployed on AWS. Developed content ingestion services for dealer feeds across UK/France/Germany using Kotlin/Spring Boot and AWS messaging (SQS/SNS, Kafka, Kinesis) to propagate real-time changes. Added operational automation using ArgoCD, Kubernetes, and scripts to schedule ingestion where full automation wasn’t possible. Worked within CI/CD environments and contributed to automated testing and UI flows with Playwright.

Senior Kotlin Developer - Contract at Sedex

Developed platform APIs using Kotlin and Http4k to expose supply chain data to other APIs and front-end applications, focusing on REST principles, clean code, design patterns, performance, and fault tolerance. Helped build and extend an event-driven architecture using Kafka for fault tolerance and scalability under varying load, including the use of backpressure queues and partitions. Implemented idiomatic Kotlin event processors as producers/consumers for ETL and real-time supply-chain updates. Also contributed to the Sedex front-end using React with TypeScript and NextJS for internal web apps. Supported a comprehensive testing pyramid (BDD with Playwright for UI, Kotlin functional tests for APIs, PACT contract tests, and automated smoke/regression tests).

Senior Java & Data Engineer - Contract at Marks & Spencer (101 Ways)

Created a new delta lake in Databricks for large-scale omnichannel data ingestion and real-time aggregation. Ingested Google Contact Centre datasets (CCAI), Zendesk APIs, and M&S/Azure lake datasets into Databricks to enable dashboards and PowerBI insights. Built transformations using DBT with TDD/unit tests and data tests for quality and integrity, and set up automated DBT project deployment to Databricks using Git hooks. Developed orchestration pipelines using Azure Data Factory. Also created performant domain APIs using Kotlin and Micronaut/Spring Boot to serve large datasets (orders/payments/access/authentication/content/contact centre). Contributed to Onyx marketplace web applications using NextJS/TypeScript and supported performance/load testing using Gatling and functional tests using Playwright.

Senior Kotlin Developer - Contract at Ford Motor - Smart Mobility

Built high-performance microservices for Kerbside data (“Kerbside FastAPI”) by optimizing slow SQL into smaller asynchronous calls to improve throughput and latency. Achieved performance improvements (reported 50x) and supported scaling across cities. Developed a Parking Sign Reader API to convert parking sign images into parking rules using ML-based cropping, Google Vision OCR, and a custom lexical parser outputting structured JSON rules, reducing onboarding effort and costs. Delivered related management tools and real-time updates via WebSockets, plus contributions to a React Native Go Park app and supporting APIs for geo-based parking data.

Senior Java Developer - Contract at Tesco (101 Ways)

Built access & authentication microservices in RxJava/Spring Boot on AWS and Azure for authenticating Tesco employees and customers. Implemented multiple authentication mechanisms based on requirements (card-based, access token, remote authentication, etc.) emphasizing high throughput and low latency. Developed admin UI tools for maintaining user/employee/role/authentication data using React/Redux. Set up Gatling-based performance comparisons between DynamoDB and Azure Cosmos, and wrote Cucumber tests for smoke/functional/performance; added Cypress tests for UI applications.

Senior Kotlin Developer - Contract at Ford Motor

Contributed to Last Mile Delivery (LMD) route planning using travelling salesman-type algorithms and later a machine-learning approach through experiments. Refactored and rewrote underperforming Node.js/Java microservices into Kotlin/Spring/Spring Boot with Hystrix to achieve low latency/high throughput. Automated continuous deployment via Jenkins pipelines (Dev/QA/Stage/Production) including build/test/deploy steps. Implemented smoke test suites using Cucumber/Gradle to safely deploy to new environments with PCF blue/green. Introduced team BDD with Cucumber using Kotlin for functional testing.

Lead Java Developer - Contract at Elsevier

Set up AWS SNS/SQS streaming events and used Apache Camel to ingest events. Built pipelines to automate content creation/updating/publishing, parsed XML into JSON metadata and denormalized XML into faster retrieval structures. Created content microservices using paging/caching solutions and AWS services for storing/retrieving documents, and built event-driven back-office services using DynamoDB and Lambda functions. Developed SSO/authentication using JWT with 20+ authentication mechanisms, implemented BDD with Cucumber for functional testing with business/technical collaboration, and created GoCD CI/CD pipelines plus smoke/regression suites. Used monitoring tools like Kibana and Graphite/Hosted Graphite.