Senior Lead Software Engineer – Full Stack, Retail Solutions

Marsh McLennan

Senior Lead Software Engineer building cloud-native SaaS solutions for major retailers. Leading technical direction and mentoring teams in a product-focused engineering organization.

Posted 6/18/2026full-timeMadrid • 🇪🇸 SpainSeniorWebsite

Tech Stack

Tools & technologies

AzureCloudDistributed SystemsFlaskJavaScriptKubernetesMicroservicesMongoDBPandasPostgresPythonTypeScriptVue.js

About the role

Key responsibilities & impact

Lead the design, development and operation of new capabilities across our SaaS products.
Make architectural decisions that balance immediate business needs with long-term scalability and maintainability.
Work closely with product, engineering and business leadership to shape product roadmaps and technical strategy.
Identify and drive improvements across performance, reliability, scalability, security and developer experience.
Champion modern engineering practices, including AI-assisted development tools such as GitHub Copilot.
Lead the adoption of new patterns, frameworks and platform capabilities across teams.
Mentor engineers and foster a culture of continuous learning, operational excellence and high-quality delivery.
Partner with platform, security and compliance teams to ensure our products meet organisational and regulatory standards.
Contribute directly to production code and remain deeply involved in technical implementation.

Requirements

What you’ll need

7+ years of software engineering experience
Experience as a Senior Engineer, Lead Engineer, Staff Engineer or Software Architect
A degree in Computer Science, Engineering, Data Science or a related field (preferred but not essential)
Certifications such as Azure Solutions Architect or CKA (beneficial but not required)
Experience working in consulting or client-facing environments (helpful but not essential)
Building and operating modern full-stack applications using technologies such as JavaScript/TypeScript and Python
Frameworks such as Express.js, Vue.js, Flask and Pandas
Designing distributed systems, service-oriented architectures and microservices
Cloud-native development, ideally on Azure Kubernetes-based platforms and deployment practices AKS and supporting technologies such as ArgoCD, Helm, Dapr and GitOps workflows
Database technologies including MongoDB and PostgreSQL
DevSecOps, Infrastructure as Code and CI/CD practices
Large-scale data platforms, data warehouses or lakehouses (Databricks experience is advantageous)

Benefits

Comp & perks

Real Impact Our products support some of the world's largest retailers in making critical commercial decisions. You'll see the direct impact of the software you build.
Engineering-Led Culture We value strong technical thinking, continuous improvement and collaborative problem-solving. Great ideas can come from anywhere.
Ownership & Autonomy You'll be trusted to make decisions, shape solutions and influence the future direction of our products and platform.
Start-up Energy, Global Reach You'll work within a fast-growing product organisation backed by the scale, reputation and expertise of Oliver Wyman.
Diverse, International Team Our engineers are distributed across multiple countries, with strong hubs in the UK and Spain, creating a collaborative and inclusive environment built on learning and shared success.

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Hard Skills & Tools

software engineeringfull-stack applicationsJavaScriptTypeScriptPythonExpress.jsVue.jsFlaskPandasmicroservices

Soft Skills

leadershipmentoringcontinuous learningoperational excellencehigh-quality deliverycollaborationcommunicationstrategic thinkingproblem-solvingadaptability

Certifications

Azure Solutions ArchitectCKA