Summary: As a Principal Engineer II, you will lead development teams, define client tech strategies, and mentor teams to adopt best practices, influencing C-level leaders and becoming an expert in cutting-edge technologies. Highlights: 1. Lead development teams and define client tech strategies 2. Mentor teams, influence C-level leaders, and become a recognized expert 3. Design and deliver innovative technology solutions across industries Job ID: 106079 - Madrid Do you want to work on complex and pressing challenges—the kind that bring together curious, ambitious, and determined leaders who strive to become better every day? If this sounds like you, you’ve come to the right place. YOUR IMPACT As a Principal Engineer II, you will lead development teams to deliver enterprise\-grade software, define client tech strategies, and mentor teams to adopt best practices. Your role offers the chance to work across industries, influence C\-level leaders, and become a recognized expert in cutting\-edge technologies. You will architect and deliver enterprise\-grade software solutions while mentoring and coaching client teams to adopt best practices. Your role will include leading multiple development teams, defining short\- and long\-term technology strategies, and collaborating with cross\-functional teams to solve complex user and business challenges. You will also establish metrics and KPIs to align teams and ensure scalable, data\-powered solutions. Your work will have an impact beyond the products you build. By working directly with C\-level leaders, you will influence strategic decisions and help clients not only build innovative software but also the teams and engineering cultures needed to sustain their growth. Each project will expose you to new industries and technologies, providing opportunities to learn and grow every day. You will lead the design and delivery of innovative technology solutions that transform businesses across industries. Based in Madrid, you will be part of QuantumBlack, AI by McKinsey, a multidisciplinary group of software engineers, AI engineers, data scientists, and technology consultants passionate about creating industry\-shaping products and tools. Your role offers unparalleled opportunities for growth and expertise. At McKinsey, you’ll have access to senior leaders eager to hear your insights, the chance to work across diverse industries, and the resources to become a leading expert in your field. Supported by a collaborative and innovative team, you will make a lasting impact on clients, industries, and the future of technology. YOUR GROWTH Driving lasting impact and building long\-term capabilities with our clients is not easy work. You are the kind of person who thrives in a high performance/high reward culture \- doing hard things, picking yourself up when you stumble, and having the resilience to try another way forward. In return for your drive, determination, and curiosity, we'll provide the resources, mentorship, and opportunities you need to become a stronger leader faster than you ever thought possible. Your colleagues—at all levels—will invest deeply in your development, just as much as they invest in delivering exceptional results for clients. Every day, you'll receive apprenticeship, coaching, and exposure that will accelerate your growth in ways you won’t find anywhere else. When you join us, you will have: * Continuous learning: Our learning and apprenticeship culture, backed by structured programs, is all about helping you grow while creating an environment where feedback is clear, actionable, and focused on your development. The real magic happens when you take the input from others to heart and embrace the fast\-paced learning experience, owning your journey. * A voice that matters: From day one, we value your ideas and contributions. You’ll make a tangible impact by offering innovative ideas and practical solutions, all while upholding our unwavering commitment to ethics and integrity. We not only encourage diverse perspectives, but they are critical in driving us toward the best possible outcomes. * Global community: With colleagues across 65\+ countries and over 100 different nationalities, our firm’s diversity fuels creativity and helps us come up with the best solutions for our clients. Plus, you’ll have the opportunity to learn from exceptional colleagues with diverse backgrounds and experiences. * World\-class benefits: On top of a competitive salary (based on your location, experience, and skills), we provide a comprehensive benefits package to enable holistic well\-being for you and your family. YOUR QUALIFICATIONS AND SKILLS * Undergraduate or master’s degree; or equivalent experience * 11\-15\+ years of experience in software development and architecture with a demonstrated track record of successfully understanding the business requirements and designing realistic and effective solutions * Active in the tech community (e.g. contributing to open source projects, speaking at conferences, blogging, etc.) and experience working collaboratively with technical and non\-technical team members and stakeholders * Experience writing unit tests with major frameworks (e.g., Karma, JUnit, NUnit, MSTest) and practicing test\-driven development * Demonstrated knowledge and hands\-on experience across the full application stack with some of the following languages/frameworks: JavaScript, TypeScript, React, Angular, Vue, jQuery, Java, Sprint, C\#, .NET, Node.js, SQL, MySQL, SQL Server, MongoDB, cloud\-native databases, AWS, Azure, GCP, Jenkins, Docker, Circle CI, Travis Engineering practice experience such as code refactoring, design patterns, design\-driven development, continuous integration, building highly scalable applications, application security * Experience leading in Agile teams, including coaching and modeling Agile mindsets as part of sprint ceremonies, work definition and building developer capabilities. * Strong communication skills, both verbal and written, in English and Spanish, with the ability to adjust your style to suit different perspectives and seniority levels