Sr. Software Engineer, C++ (Madrid-based)

Description

This position is for a Senior Software Engineer to join the Product CX CI Team — a vertical team delivering customer-facing features (doctor-facing and CAD) at Align Technology.

As a Senior C++ Software Engineer, you will lead feature delivery end-to-end across computational geometry, treatment planning logic, and backend services — owning technical decisions from requirements through release.

This role is expected to act as a technical anchor on the team: raising the engineering bar, closing technical decisions without escalation, and coaching less experienced engineers.### Key Responsibilities

• Own features end-to-end — from requirements clarification and architecture through implementation, review, release, and post-release monitoring
• Design and implement 3D geometrical and numerical algorithms in C++ for customer-facing planning scenarios (doctor-facing and CAD)
• Contribute to backend services in Go supporting the customer-facing applications
• Lead architecture discussions; propose, defend, and close technical trade-offs with clear reasoning
• Drive clarification of ambiguous or incomplete requirements together with Business Analyst, Product Manager, and QA.
• Coordinate directly with adjacent teams on cross-team dependencies — own the outcome
• Set the quality bar in code reviews; mentor junior and mid-level engineers through reviews, pairing, and design guidance
• Work closely with the SQA team; contribute to test infrastructure and testability of the code you write
• Maintain traceability and regulatory documentation for medical software, following documentation-as-code practices

Skills, Knowledge \& Expertise

• Degree in Computer Science, Mathematics, Physics, or Engineering
• 8+ years of hands-on software engineering experience in a product team
• Demonstrated ownership of multiple non-trivial features taken from requirements to production
• Track record of technical leadership on at least one complex feature or subsystem

C++ (primary):

• Strong expertise in modern C++ (C++14/17 or later), deep knowledge of STL
• Experience building high-performance numerical or geometry algorithms

Go (complementary):

• Practical experience building backend services in Go, including HTTP/WebSocket endpoints
• Familiarity with gRPC and Protocol Buffers

General:

• Ability to write testable, object-oriented code; strong opinions on design and testability
• Solid understanding of algorithms; experience with 3D geometry, linear algebra, or analytical geometry is a strong advantage
• Experience with Git and CI systems (Bamboo or equivalent)
• Working knowledge of Python for tooling and scripting
• Able to explain technical trade-offs clearly — why option A was chosen over B, what was rejected and why
• Comfortable leading discussions with BA, PM, QA, and peer engineers to close decisions
• Writes clear design notes, commit messages, and documentation
• Proactive: talks to adjacent teams directly for context instead of escalating
• Takes initiative on process and quality
• Actively mentors junior and mid-level peers
• Ownership mindset
• Upper-intermediate English (B2 or higher) — all internal communication is in English
• Comfortable working in a regulated (medical) industry with strict process and documentation requirements
• Effective under tight timelines and in changing environments
• Learns new technologies quickly
• AWS Lambda and other serverless patterns
• Hands-on experience with Jira and Confluence
• Hands-on experience using AI-powered tools in day-to-day software development

About Align Technology

Your growth and well-being:

At Align, every smile matters. We’re committed to helping you thrive by supporting the health, growth, and well-being of our team members through a variety of tools and programs. While specific offerings may vary by location and role, Align employees can typically expect:* Health and well-being programs to keep you thriving in both body and mind. * Employee-exclusive discounts on Invisalign products. * Learning opportunities through online learning resources and support for your individual development plans. * Inclusive, global workplace that fosters collaboration, recognition and belonging.

Country and/or role specific details will be shared with you by your recruiter during the interview process.

Discover Align:

We are a global community of game-changers and smart team players, united by our belief in the power of a smile. Our dynamic team of exceptional employees is dedicated to transforming the industry and creating extraordinary outcomes every day.

Align’s core values of agility, customer, and accountability are more than words to work by, they are words we live by. The actions we take every day speak to who we are as a company and our focus on being truly impactful. We celebrate our differences, and the many ways we support one another— ultimately creating a more inclusive organization and world as we continue transforming smiles and changing lives.

We foster a culture where thinking differently and seeking new experiences are not just encouraged but celebrated. With the Align Mindset, we empower each other, ensuring every voice is heard and valued in an inclusive environment that inspires creativity and collaboration.

At Align, we believe in the power of a smile, and we know that every smile is as unique as our employees. As we grow, we are committed to building a workforce rich in diverse cultural backgrounds and life experiences, fostering a culture of open-mindedness and compassion. We live our company values by promoting healthy people and healthy communities, all with the intent of changing millions of lives, one unique smile at a time.

As part of our commitment to innovation, Align Technology includes exocad and Cubicure, companies that enhance our offerings and extend our impact to industry transformation.

Eager to learn how we embrace our global differences and nurture employee well-being?

Explore Align's culture here!

Want to discover more about exocad and Cubicure? Click on their names for additional information.

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Equal Opportunity Statement:

Align Technology is an equal opportunity employer. We are committed to providing equal employment opportunities in all our practices, without regard to race, color, religion, sex, national origin, ancestry, marital status, protected veteran status, age, disability, sexual orientation, gender identity or expression, or any other legally protected category. Applicants must be legally authorized to work in the country for which they are applying, and employment eligibility will be verified as a condition of hire.