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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Principal Software Engineer - **Company:** Corpay - **Location:** London, UK - **Experience:** Expert - **Contract:** Permanent contract - **Skills:** .NET Framework, Application Programming Interfaces (APIs), Amazon Web Services, Data Analysis, Sound Recording and Reproduction, C Sharp (Programming Language), Cloud Computing, Cloud Computing Security, Cloud Engineering, Code Review, Continuous Integration, Data Warehousing, Relational Databases, Distributed Systems, Amazon DynamoDB, Data Intelligence, NoSQL, Performance Tuning, Query Optimization, RabbitMQ, Redis, Distributed Caching, Message Oriented Middleware, Salesforce.Com, Secure Coding, Amazon Simple Notification Service (SNS), Software Engineering, SQL Databases, Data Streaming, Systems Integration, Tableau (Software), Software Security, Indexer, Backend, Cloudformation, Event Driven Architecture, Kubernetes, Information Technology, Low Latency, Apache Kafka, Salesforce Object Query Language (SOQL), Data Management, Amazon Simple Queue Service (SQS), Data Pipelines, Serverless Computing, GXP, Databricks, Microservices - **Published:** October 8, 2026 - **Apply:** https://startup.jobs/principal-software-engineer-cambridge-mercantile-corp-au-10327072 ## About the Role * Minimum of 7 years of professional software engineering experience, including a proven record of operating as a senior technical leader across complex, business-critical systems. * Bachelor's degree in Computer Science, Engineering, Finance or a related field, or equivalent professional experience. * The role requires strong distributed-systems and AWS expertise, together with exceptional data fluency. You will be comfortable working deeply with relational and non-relational data, SQL and other query models, and the data platforms and pipelines that underpin operational and customer-facing services. This is not a Data Engineer role; however, you will need the judgement and practical experience to guide data-related design, investigate complex issues and support teams where data is central to the solution. * Expert-level experience designing and evolving distributed systems, microservices and event-driven architectures in production environments. * Strong hands-on experience with AWS and cloud-native architectures, including serverless services and infrastructure as code. Practical experience with AWS CloudFormation is highly desirable. * Strong experience building backend applications and services using C# and modern .NET, with the ability to make sound technology choices where the estate requires other tools. * Strong knowledge of asynchronous messaging and event streaming, including technologies such as Amazon EventBridge, Amazon SQS/SNS, Kafka, RabbitMQ or equivalent. * Exceptional understanding of data: relational and NoSQL databases, data modelling, SQL, query optimisation, indexing, transactional considerations and data-access patterns. * Practical experience querying or working with data platforms and tools such as Databricks, Salesforce SOQL, DynamoDB, Tableau, data pipelines, data warehouses or equivalent technologies. * The ability to distinguish between operational and analytical data needs and to make appropriate design decisions in partnership with data specialists. * Experience designing reusable APIs, services and integrations, with a strong focus on secure development, observability, resilience and maintainability. * Strong understanding of cloud security, application security and risk-aware design within a regulated environment. * Excellent analytical and problem-solving skills, with the ability to simplify ambiguity, identify the important trade-offs and move teams toward a pragmatic decision. * Strong written and verbal communication skills, including the ability to influence senior stakeholders and explain complex technical concepts clearly. * Demonstrated experience mentoring engineers and raising technical standards across more than one team. * Experience in financial services, payments, banking, private markets or another regulated industry. * Experience with KYC, customer onboarding, account lifecycle management, CRM, operations or compliance-led workflows. * Experience with Salesforce platforms and integrations. * Experience with distributed caching, such as Redis, and performance tuning of high-volume services. * Experience with Kubernetes, CI/CD practices and modern software delivery tooling. ## Description Corpay is currently looking to hire a Principal Software Engineer within our Alpha division. This position falls under our Corporate Payments line of business and is located in London, United Kingdom. You will operate as a senior individual contributor and trusted technical leader, reporting directly to the Director of Engineering for Client Lifecycle. This is not a people-management position. You will work across multiple teams rather than being assigned to a single delivery team, partnering closely with Engineering Managers, Technical Architects, Product Managers and engineers to turn complex business and regulatory needs into clear, scalable technical solutions. At Corpay, we value engineers who are curious, collaborative and pragmatic. You will set a high technical bar while staying close to delivery, helping teams make sound trade-offs and building reliable, secure systems that can evolve with the business. How We Work As a Principal Software Engineer, Corpay will set you up for success by providing: * Assigned workspace in our London office * Company-issued equipment * Formal, hands-on training, * Provide hands-on technical leadership across the Client Lifecycle vertical, setting direction for the design, evolution and operation of systems supporting KYC, onboarding, accounts, operations and data. * Define and champion pragmatic engineering principles, architectural standards and reusable patterns that enable teams to deliver consistent, secure and scalable solutions. * Lead the design of distributed, event-driven and cloud-native systems, making clear trade-offs around consistency, resilience, scalability, security, latency and operational supportability. * Work with Technical Architects and engineering teams to translate strategic and regulatory requirements into practical target architectures, solution designs and incremental delivery plans. * Remain hands-on: prototype complex solutions, contribute production-quality code where it adds the most value, and unblock teams working through difficult technical problems. * Own the technical quality of cross-team initiatives, including architecture reviews, design assurance, production readiness and the identification of technical risks or dependencies. * Use deep data knowledge to guide data modelling, access patterns, data quality, lineage, retention and performance considerations across operational and analytical use cases. * Analyse and query data across relevant platforms to investigate problems, validate assumptions and support decision-making, using SQL and appropriate query models for technologies such as Databricks, Salesforce, DynamoDB and reporting or warehouse platforms. * Work with data and platform specialists to ensure data pipelines, warehouses and integrations are reliable, observable, governed and fit for the needs of the wider vertical. * Champion AWS-native design and operational practices, including secure and resilient use of serverless, messaging, storage, compute, identity, observability and infrastructure-as-code capabilities. * Guide teams in building secure APIs, backend services and integrations that meet the needs of business-critical financial services and regulated customer journeys. * Review code, designs and technical proposals; provide constructive challenge and coaching that raises engineering quality without becoming a delivery bottleneck. * Mentor engineers and technical leaders, creating clarity on good engineering practice and helping build stronger technical judgement throughout the group. * Investigate complex production issues and systemic performance or reliability concerns, driving root-cause analysis and durable improvements. * Communicate technical strategy, risks, trade-offs and progress clearly to technical and non-technical stakeholders, including senior leadership.