About this role
Salary: £? - ? per year
Requirements: Strong software development experience, ideally using Python.Hands-on experience developing Thought Machine Vault Smart Contracts.Good understanding of Vault Core, including Smart Contracts, Contracts API / Vault APIs, posting instructions, balances and dimensions, scheduled events, hooks, interest accrual and application, and account lifecycle management.Strong experience developing and testing complex business logic.Good understanding of banking product concepts and financial calculations.Experience with automated testing and test-driven development.Strong analytical and problem-solving skills.Experience working with Git-based development workflows, CI/CD pipelines, and modern software engineering practices.Ability to work effectively within multidisciplinary Agile delivery teams.Strong communication skills and the ability to discuss complex technical behaviour with both technical and non-technical stakeholders.Experience implementing Lending and/or Savings products.Experience migrating financial products from legacy core banking platforms onto Thought Machine Vault.Understanding of Lending and Savings concepts, including interest accrual and application, repayment schedules, fixed and variable interest rates, fees and charges, overpayments and underpayments, deposits and withdrawals, account maturity, and product and account closure.Experience working with financial event streams and downstream accounting or reporting systems.Knowledge of reconciliation between legacy and target banking platforms.Experience working within UK financial services or another highly regulated banking environment.Familiarity with microservices, event-driven architectures, and cloud-native platforms.Experience working with Jira, Confluence, and Agile/Scrum delivery practices. Responsibilities: Design, develop, and maintain Thought Machine Vault Smart Contracts for Lending and Savings products and associated product features.Translate business and product requirements into scalable and maintainable Smart Contract implementations.Develop product logic covering interest calculation and accrual, repayment and payment schedules, fees and charges, payment allocation, account balances and balance dimensions, product lifecycle events, and account amendments and servicing activities.Support the implementation and migration of Lending and Savings products onto the new core banking platform.Work closely with Business Analysts and Product Owners to clarify requirements, identify edge cases, and define expected product behaviour.Collaborate with architecture and engineering teams to ensure Smart Contracts integrate correctly with surrounding services and platforms.Develop comprehensive automated tests covering product rules, scenarios, boundary conditions, and regression behaviour.Participate in code reviews and contribute to development standards and engineering best practices.Investigate and resolve defects identified during functional, integration, migration, and production testing.Support reconciliation and validation of financial calculations between legacy systems and Vault.Analyse existing product behaviour and legacy-system rules when supporting product migration.Contribute to technical design discussions and identify potential implementation risks or constraints.Support releases through development, testing, pre-production, and production environments.Produce appropriate technical documentation describing Smart Contract behaviour and key implementation decisions.Work within established engineering governance, security, and regulatory requirements. Technologies: APIARMCI/CDCloudConfluenceGitSupportJIRAPythonSecuritymicroservicesC++ More:
We are supporting a major Core Banking transformation programme and are looking for an experienced Smart Contract Developer to join our team for a 6-month contract on an Inside IR35 basis, offering up to £625 per day. The role is London-based with hybrid working, requiring 3 days per week onsite. You will work within the Product Vault capability on a next-generation core banking platform based on Thought Machine Vault Core, partnering with Product Managers, Business Analysts, Solution Architects, QA Engineers, and other engineering teams to deliver Lending and Savings capabilities. This opportunity is being advertised by ARM, a specialist talent acquisition and management consultancy supporting technical recruitment across key industries.
last updated 32 week of 2026