Senior Full Stack Product Engineer

• Contribute as a main developer to one of our web projects, owning the stack end to end. • Work as a real counterpart to the Product team: define, shape and estimate new features and products, contributing to what we build and not only how. • Translate business and monetization goals into technical decisions, and explain the trade-offs behind them. • Contribute and implement software development best practices (such as CI/CD, automated testing, code reviews) with the Engineering Team. • Define and track a set of metrics to evaluate the health of the project: monitoring performance, stability, and code quality. • Enhancing the importance of team unity so that everyone feels part of the project and the company.

We're looking for a Senior Full Stack Product Engineer to join our dream team and help us release the best web products for our innovative, industry-leading products. If you're a highly motivated person with a real interest in tech, a passion for building cutting-edge products, and opinions about what gets built and not only how it gets built, we've got the perfect job for you! A little bit about us Leadtech has fostered and developed innovative digital businesses across various industries since 2009. We've now got a team of over 800 dedicated employees working around the world, especially in Spain. We're really proud to have more than 23 nationalities working together, and we love that millions of users around the globe enjoy our products and services every month. #LifeAtLeadtech Key responsibilities: • Contribute as a main developer to one of our web projects, owning the stack end to end. • Work as a real counterpart to the Product team: define, shape and estimate new features and products, contributing to what we build and not only how. • Translate business and monetization goals into technical decisions, and explain the trade-offs behind them. • Contribute and implement software development best practices (such as CI/CD, automated testing, code reviews) with the Engineering Team. • Define and track a set of metrics to evaluate the health of the project: monitoring performance, stability, and code quality. • Enhancing the importance of team unity so that everyone feels part of the project and the company. Your team • We’re team-first.If you believe in the power of collaboration and that the team’s success is your success, then you’re one of us! • Fun is fundamental. We believe in forming strong bonds in and outside the office. That’s why we have a team-building budget and organize activities to enjoy ourselves. • Positivity wins the day. Bring a positive attitude and communicate openly. Self-awareness and an openness to learn are always a plus. Required skills: • Bachelor's or Master's degree in Software Engineering, Computer Science, or a related field — or equivalent demonstrable experience. • You have solid previous experience (more than 5 years) developing robust and scalable frontend applications, backend applications, and APIs. • Strong knowledge of Software Engineering design patterns. • You have product and design instinct: you have opinions about the interface, you push back on specs when something doesn't make sense, and you care about aesthetics and interaction quality beyond whether the feature works. • You understand the business: conversion, churn, retention and margin, and how technical decisions move them. You can frame a trade-off in business terms and defend it. • You have demonstrable experience working with React, Next.js, Node.js, TypeScript, and JavaScript in building web and backend applications. • Knowledge of other web and backend development technologies is highly valued. • You know web design patterns and how to adapt them optimally to mobile. Most of our users reach our products through a mobile browser, so you design for small screens and touch interaction from the start, rather than scaling down a desktop layout. • You use AI in your development processes, multiplying your productivity without losing control. • You can work through an unfamiliar codebase, explain what it does, and find the bug when the AI's answer is wrong. • You are familiar with and have practical experience with Google Cloud Platform and its relevant services for backend development (e.g., Compute Engine, Cloud Functions, Cloud Firestore, BigQuery, etc.). • You possess knowledge and experience working with both relational (e.g., PostgreSQL, MySQL) and non-relational databases (e.g., Cloud Firestore, MongoDB). • Data warehousing solutions like DataBricks or BigQuery are highly valued. • You master the definition and implementation of software development best practices, ensuring code quality and maintainability. • You feel comfortable and enjoy working in agile and dynamic environments, adapting to changes and actively contributing to planning. • You possess excellent communication skills, both verbal and written, to interact effectively with the technical team and other stakeholders. Benefits WHY LEADTECH • Diversified app portfolio with millions of active users in a high-growth non-gaming vertical. • Mature data infrastructure: BigQuery, Looker, AppsFlyer, and a proprietary analytics stack for fast decision-making. • Experimentation culture: real autonomy to propose and ship changes in production. • International team, dynamic environment, and the opportunity for direct P&L impact. • Competitive compensation package + benefits (flexible hours, health insurance, training). Growth and career development • At Leadtech, we prioritize your growth. Enjoy a flexible career path with personalized internal training and an annual budget for external learning opportunities. Work-Life balance • Benefit from a flexible schedule with flextime and the option of working full remote or from our Barcelona office. Enjoy free Friday afternoons with a 7-hour workday, plus a 35-hour workweek in July and August so you can savor summer! Comprehensive benefits • Competitive salary, full-time permanent contract, and top-tier private health insurance (including dental and psychological services). • 25 days of vacation plus your birthday off, with flexible vacation options—no blackout days! Unique Perks • If you wish to come, in our office in Barcelona you’ll find it complete with free coffee, fresh fruit, snacks, a game room, and a rooftop terrace with stunning Mediterranean views. • Additional benefits include ticket restaurant and nursery vouchers, paid directly from your gross salary. • Join us in an environment where you’re free to innovate, learn, and grow alongside passionate professionals. At Leadtech, you’ll tackle exciting challenges and be part of a v