What are the responsibilities and job description for the Senior Full Stack Engineer position at Smadex SLU?
Smadex is a performance advertising engine for mobile apps, enabling the world's leading marketers to grow across Mobile and Connected TV (CTV). Powered by AI models trained on real campaign outcomes, Smadex delivers profitable growth at scale. Headquartered in Barcelona, with teams across the Americas, EMEA, and APAC, Smadex is a business unit of Entravision (NYSE: EVC).
As a Senior Full Stack Engineer, you will serve as the technical anchor and architectural pillar for the team. Partnering closely with our delivery and operational team lead, you will take ownership of technical excellence, establish sound architectural standards, and mentor the team. This is a high-impact, hands-on Individual Contributor (IC) role where your judgment will shape both our browser-facing tools and our runtime creative execution.
Your Tasks and Responsibilities
- Architect Scalable Creative Tools: Lead the technical design, development, and delivery of core features across internal creative tooling utilizing modern Angular and TypeScript.
- Master High-Performance Runtimes: Guide the engineering of ultra-lightweight client-side components and interactive playable ads optimized for mobile webview performance, strict bundle-size limits, and sandboxed iframe execution.
- Own Server-Side Pipelines: Architect and maintain resilient Node.js microservices and pipelines handling dynamic asset generation, headless bundling, and low-latency tracking/redirect logic.
- Elevate Engineering Standards: Drive high-signal pull request reviews, author technical RFCs, introduce pragmatic automated testing, and proactively resolve technical debt.
- Technical Mentorship: Coach and mentor mid-level engineers, instilling best practices in web fundamentals, design patterns, and advanced debugging.
What Are We Looking For?
- 5 years of professional software engineering experience, with deep expertise across modern TypeScript in both client and server environments.
- Advanced Angular Knowledge: Strong mastery of modern Angular architectures (Signals, Standalone Components, reactive state management, change detection strategies, and modular code organization).
- Solid Node.js Foundations: Strong understanding of asynchronous event loops, streaming I/O, headless compilation/bundling workflows, and REST/microservice API design.
- Deep Browser & Runtime Fundamentals: Strong grasp of DOM/Canvas performance, memory lifecycle management, iframe sandboxing, postMessage communication protocols, and asset loading optimization.
- Architectural Judgment & Code Quality: Proven track record of conducting high-signal code reviews, designing maintainable systems, and introducing pragmatic automated testing.
- Low Ego, High-Impact Mentorship: Genuine passion for coaching other engineers, explaining the why behind technical decisions, and elevating team-wide technical criteria.
Bonus Points:
- Familiarity with the digital advertising ecosystem (MRAID specifications, tracking macros, click-through handling, or attribution models).
- Experience with HTML5 Canvas, WebGL, or lightweight rendering libraries (PixiJS, Phaser, Three.js) for interactive creatives.
- Hands-on experience with modern JavaScript bundlers and build tools (esbuild, Vite, Rollup, or custom AST transformation pipelines).
- Experience implementing automated CI/CD performance and bundle-budget monitoring.
What We Offer
- Integrate a highly motivated, young and dynamic team
- Great compensation package
- Top location at the heart of Barcelona with a rooftop terrace, Barbecue, and a fully stocked fridge
- Great work-life balance: work from home (2 days per week), flexible hours
- Meal vouchers - Ticket Restaurant monthly allowance
- Monthly gym allowance: Choose between DiR and Wellhub
- LinkedIn Learning and training opportunities
- Monthly TGIF events
- Regular team-building events
- Fun and friendly work environment with talented marketers and engineers from over 40 countries
- And more!
If you want to know more about us visit our website Smadex.com, and for a sneak peek of the cool stuff we build check this video out! And, if you are ready to take your career to the next level and tackle engineering challenges at a global scale, we encourage you to apply!
Please note that we do NOT provide VISA sponsorship. Candidates without a legal permit to work in Spain won't be considered.