The English-language job board for Spain

Senior Full Stack Engineer

Hybrid in Barcelona·Full-time·Added yesterday (last checked 2 Nov)

Smadex

16 open roles

Apply

Our summary

Work mode: Hybrid, Barcelona
Contract: Full-time
English: Required
Experience: 5+ years
Benefits: Meal vouchers, gym access

Visa options

The ad rules out sponsorship
Per the ad: “Please note that we do NOT provide VISA sponsorship. Candidates without a legal permit to work in Spain won't be considered.”

Find jobs with visa support

Skills

Nice to have

Requirements

What we're 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.

Nice to have

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.

Pay & benefits

What you'll get

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!

The role

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.

What you'll do

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.

About Smadex

Smadex is a Madrid-based advertising technology company specializing in programmatic mobile advertising and performance marketing. The company provides a demand-side platform (DSP) that enables advertisers to run targeted campaigns across mobile apps and web, with a strong focus on data-driven optimization and creative innovation. Smadex operates globally, with a team of over 100 professionals serving clients across Europe, the US, and other international markets.

Smadex's headquarters and main engineering hub are in Madrid, Spain, making it a key player in the local AdTech ecosystem. The company is known for its collaborative, data-centric culture and invests heavily in machine learning, data science, and creative technology. For international professionals, Smadex offers the opportunity to work in a fast-growing, global-facing company in the heart of Spain, with roles spanning engineering, data science, product, and creative strategy.

Industry: AdTech
Founded: 2011
Employees: 100–500
Headquarters: Madrid, Spain
In Spain: Madrid

Good to know if you are moving

Smadex is headquartered in Madrid, Spain, offering international professionals the chance to work in a vibrant European capital with a growing tech scene.
The company operates globally, with clients and partners across Europe, the US, and Asia, providing exposure to international markets.
Smadex focuses on data-driven advertising, making it an attractive employer for data scientists, machine learning engineers, and product managers.
The company has a strong emphasis on creative technology, with roles like Creative Technologist and Game Developer for playable ads, offering unique opportunities in the AdTech space.
Smadex is a mid-sized company, allowing employees to have a significant impact on products and processes.

In their own words

About the company & team

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).

Additional information

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.

All open roles at Smadex