Principal Software Engineer – CSD Integration

Principal Software Engineer – CSD Integration & Asset Servicing
- Logo### Principal Software Engineer – CSD Integration & Asset ServicingApply: Paris: Full time: Posted Today: R29485##

About the role
Euronext is building digital-asset services on its existing securities-market infrastructure. We are looking for a Principal Software Engineer to design and build the CSD capabilities that connect the two.
You will lead the architecture of the CSD Integration, Asset Servicing & Reporting team. The team builds the gateway and services that connect digital-asset applications to Euronext Securities for securities lock and release, settlement status, corporate actions and reporting. We reuse existing CSD capabilities; we do not rebuild the CSD.
You are both architect and developer: you design the solution, write production code in the team’s codebase and review your colleagues’ code. This is not a product-owner or functional-analyst role. ## About the missionThe team owns the CSD side of Euronext Digital Assets: the CSD gateway for lock and release, T2S instructions and confirmations, corporate actions, T2 and Pontes, and reporting to custodians.
You will take these services from the first issuance and settlement flows to a scalable asset-servicing platform. You will agree the CSD gateway interface with the tokenisation-engine team and work with the principal architect, who owns the end-to-end design across teams. ## What you’ll do
* Own the team’s technical architecture: designs, interface contracts, standards and roadmap.
* Contribute production code to the codebase, starting with the most critical components such as the CSD gateway.
* Review code: pull requests, coding standards, test coverage and security of the codebase.
* Design the CSD gateway and its T2S integration: lock and release, instructions, queuing, cut-offs, confirmations and status.
* Design for failure, not only the normal flow: duplicate or delayed messages, retries, partial failures, corrections, reconciliation breaks and auditable exception handling.
* Reuse and extend existing Euronext Securities systems rather than duplicate them.
* Shape the architecture for corporate actions, entitlements and reporting to custodians.
* Set and test non-functional

requirements:
resilience, performance, security, recoverability and observability.
* Build prototypes and lead build, buy and integration decisions.
* Work with the product manager, who owns priorities and requirements; you own the technical solution.
* Help the team build, test and run what it ships: environments, CI/CD, monitoring, runbooks and support during T2S operating hours. ## What you bringRequired: post-trade and system knowledge
* Strong knowledge of securities post-trade: settlement, custody, corporate actions and CSD operations.
* T2S

experience:
settlement instructions, lifecycle, cut-offs and status reporting.
* ISO 20022 settlement messaging and SWIFT connectivity.
Required: architecture and design
* Solution architecture for regulated, high-availability systems: security, resilience and auditability.
* Event-driven architecture and domain-driven design.
* Integration with legacy financial-market platforms, modernised step by step without disrupting live operations.
Required: technical implementation
* Backend development in Go and/or Java: production code, not only prototypes.
* REST APIs (OpenAPI), Kafka and message brokers such as ActiveMQ.
* SQL and NoSQL data stores.
* Containers on Linux: Docker, Kubernetes or OpenShift.
* Git, CI/CD, test automation, infrastructure as code (e.g. Terraform) and observability (e.g. OpenTelemetry).
* AI-assisted development: daily use of coding assistants, with review guardrails for AI-generated code.
Required: experience and leadership
* 8+ years of software engineering on production systems, including 3+ years as lead engineer, software architect or solution architect, while still writing and reviewing code.
* Technical leadership: set standards, explain trade-offs to technical and non-technical audiences, coach engineers.
* Degree in computer science, engineering or a related field, or equivalent experience.
* Fluent in English.
Nice to have
* T2 and Pontes.
* Cross-CSD links.
* Corporate-actions platforms.
* Public cloud (AWS).
* DLT and blockchain: a plus, not a requirement. Join Euronext – Shape capital markets for future generationsJoin a company where market infrastructure is built on innovation — and where every innovation starts with a bold mind asking, “What’s next?”. At Euronext, we believe change is a starting point, not an obstacle. We look for people who see growth opportunities, think long term, and want to help shape capital markets for future generations. ## Working with us means:
* Being part of an international, diverse and innovative team.
* Developing your skills through continuous learning and real responsibilities.
* Contributing to projects that matter in a dynamic environment.
* Playing an active role in building transparent, responsible and sus