Senior Software Engineer – Data & Ads Tech Project

Description

Job Summary: We are looking for a Senior Software Engineer to join the engineering team and contribute to the development of high-impact products, working with modern technologies and large volumes of data. Key Highlights: 1. You will be part of the core engineering team 2. You will participate in the entire product lifecycle 3. Strong technical culture and low turnover Description At **Q\-tech**, we are collaborating with an **international technology company** operating at the intersection of **mobile data, digital advertising, and privacy**, helping global brands optimize their marketing strategies intelligently and securely. Founded in **2012**, the company integrates **anonymous mobile network data** with advertising platforms to enable advertisers to reach highly segmented audiences and maximize campaign performance — always under a **privacy\-first** approach. Its ability to transform large volumes of data into **actionable insights** has positioned it as a key player in the AdTech \& Telco ecosystem. With its **headquarters in Silicon Valley and global presence**, it works closely with leading mobile operators and technology companies. Additionally, it stands out for its **sustained growth**, **strong technical culture**, and **very low turnover**, with an average team tenure of **5 to 7 years**. Currently, the team continues expanding and seeks to hire a **Senior Software Engineer** eager to contribute to the development of high-impact products, working with modern technologies and large-scale data. Your Role You will join the core engineering team and participate in the full product lifecycle: from design through implementation and evolution of solutions. Your responsibilities will include: * Understanding and evolving the platform’s current **architecture** and data flows * Designing and developing scalable and resilient **microservices** * Optimizing the **data architecture** to generate new insights * Building efficient methods for data extraction, processing, and consolidation * Ensuring **software quality** through unit and integration testing * Participating in **code reviews** and proposing technical improvements * Documenting architecture, data flows, and key components * Maintaining and improving the existing codebase * Collaborating with QA to define test plans * Supporting DevOps/SRE during deployments * Estimating tasks and committing to deadlines * Acting as a technical reference, communicating decisions and solutions * Evaluating new tools and technologies that add value to the team What We’re Looking For **Mandatory:** * Bachelor’s or Master’s degree in Computer Engineering, Computer Science, or related field * **3–5 years of experience with Java** * Experience with **Java, Spring (Boot \& Cloud)**, and **Maven** * Solid knowledge of **distributed architectures**, event-driven systems, fault tolerance, CRUD, etc. * Experience with **SQL and NoSQL databases** * Optimization of **complex, high-volume SQL queries** * Use of **gRPC, Protobufs**, and messaging platforms such as **Apache Kafka** * Experience with **AWS**, virtualized environments, and **Linux** * English proficiency at **Upper\-Intermediate** level or higher **Also Valued:** * Experience with **Python** and **shell scripting** What They Offer * **Permanent contract** * Stable project within a company experiencing **strong growth** * **Flexible working hours** and work-life balance * **On-site attendance** (a highly flexible hybrid model) * **MacBook Pro M3** \+ additional budget for equipment * Senior, collaborative, quality-focused technical team * Real technical challenges involving **large-scale data** and modern architecture 55\.000€ \- 70\.000€ Zaragoza/Barcelona/Madrid Hybrid **Contact Person:** ediaz@q\-techrec.com \+34 663 444 972