Senior

Q-tech; Cataluña; Presencial; EUR 45.000 - 65.000; Jornada completa

Descripción de la vacante

A fintech startup in Spain is looking for a Senior Backend Engineer to design and scale resilient backend systems. The ideal candidate has strong Python and AWS skills, with a focus on clean code and collaboration in a multidisciplinary team. This role offers a competitive salary and opportunities for professional growth in a dynamic work environment.

Servicios

Competitive salary between 45k€ and 65k€

Variable pay up to 10% of gross annual

26 days paid vacation

Formación

• Solid experience in Python (Django is a plus, but not strictly required).
• Previous experience in startups or scaleups.
• Strong knowledge of AWS infrastructure.

Responsabilidades

• Design and scale resilient, efficient backend systems.
• Write clean, high-quality code in Python/Django.
• Collaborate with a multidisciplinary team.

Conocimientos

Python

AWS infrastructure

Distributed systems

Ownership mindset

Descripción del empleo

Would you like to join a fast-growing international fintech startup with a product already handling hundreds of millions of euros? We are looking for a Senior Backend Engineer who wants to have a high impact from day one and be part of a small, international, and highly collaborative team.

What you’ll do

• Design and scale resilient, efficient backend systems.
• Write clean, high-quality code in Python/Django (hands‑on, daily coding).
• Take ownership of architecture and infrastructure decisions (AWS: RDS, ECS, Kafka, synchronous/asynchronous tasks).
• Collaborate with a multidisciplinary team (backend, frontend, product, security, data).
• Contribute to the evolution of a product with 150,000+ users, growing at double‑digit rates month over month.

What they’re looking for

• Solid experience in Python (Django is a plus, but not strictly required).
• Strong knowledge of AWS infrastructure and distributed systems.
• Previous experience in startups or scaleups with growing products.
• Ownership mindset and ability to bring technical vision.
• Bonus: interest in AI development platforms (e.g., Cursor).

What they offer

• Real impact on a fintech product that helps thousands of people.
• Open, collaborative, and highly international culture (team members from across Europe and LatAm).
• Office in the heart of 22@ (Barcelona), just three blocks from the beach.
• 2 days of teleworking per week.
• Dynamic environment with afterworks, team events, and two company‑wide gatherings per year.

Backend Software Engineer

Backend Software Engineer needed to develop and maintain product solutions for the aviation industry. Requires Java, Spring/Quarkus, and microservices experience.

Software Engineer

Permisso is a multinational, family‑owned industrial group with a clear vision: to create products and systems that help improve the quality of people's lives and the world around them. It operates in automotive, home appliance, HVAC, energy, and EV‑Charging sectors. Permisso is an equal‑opportunity employer and embraces diversity, equity and inclusion.

ABOUT THE OPPORTUNITY

You will play a pivotal role in shaping the future of financial services across Europe. We are on a mission to create a more transparent, fair, and user‑centric landscape, building rails to collect, process, and share real‑time data.

The main role is to build the product which is developed predominantly using TypeScript and MongoDB on the backend, React on the frontend, and Python for data extraction and parsing services. You will be part of a product team, creating new features and improving existing ones.

At Permisso, we place value in our office culture – the relationships and collaboration it builds and the creativity it brings to the table. We operate as an office‐first company, understanding remote as a tool.

WHAT YOU'LL BE DOING

• Design, develop, test, deploy and maintain software in a thriving environment.
• Focus on creating new features and improving existing ones.
• Work within your cross‑functional team to uphold high technical standards.
• Test, learn and iterate features based on market needs and customer feedback.

WHAT YOU’LL NEED

Background:

• Minimum 4 years of experience, several in a startup environment.
• Experience with agile methodologies (preferably SCRUM).

Skills:

• Object‑oriented programming following SOLID, Clean Code, Design Patterns, Unit Testing, TDD, CI/CD.
• Automatic testing knowledge and experience.
• Team collaboration in fast‑paced environments.
• Communication and organisational skills.
• Professional proficiency in English.
• Highly motivated and proactive.
• Ready to take high‑impact decisions and responsibilities.
• Motivation to keep learning well‑tested code.
• Open, direct, timely feedback.

WHAT’S IN IT FOR YOU

• Open and structured career ladder with base salary between 45k€ and 65k€.
• Variable pay up to 10% of gross annual, paid every six months.
• Early‑stage equity.
• 26 days of paid vacation, including birthday and Christmas days.

WHO WE ARE

Financial services are moving fast towards full digitalisation. Permisso is building the rails to collect, process, and share data in real time, securely and automatically.

Founded by experienced entrepreneurs and backed by top‑tier investors, Permisso aims to set a new business standard for financial services.

BITRON - Software Engineer

Bitron is a multinational, family‑owned industrial group with over 8,000 employees. It operates in automotive, home appliance, HVAC, energy, and EV‑Charging sectors.

The Automotive Business Unit is a leading global supplier of automotive components.

Your role requires deep knowledge of embedded C programming, microcontroller architecture, automotive SPICE, MISRA C, ISO 26262, ISO 21434, CAN, LIN, Ethernet, and more.

Key responsibilities include analysing customer requirements, designing and developing embedded software components, integrating legacy modules, testing, troubleshooting, and collaborating with global teams.

We are an equal‑opportunity employer and do not discriminate against any employee or applicant for employment because of race, color, sex, age, national origin, religion, sexual orientation, gender identity, status, or basis of disability or any other personal characteristics.

PROSPER AI - Software Engineer

Prosper AI specializes in AI Phone Agents for healthcare, providing human‑like expertise while reducing costs. The role is a full‑time on‑site position in Barcelona, possibly moving to New York.

Qualifications

• Bachelor’s or Master’s degree in Computer Science, Engineering, Maths, Physics or related field.
• 3‑5 years of experience building complex software solutions.
• Solid grasp of algorithms, data structures, and software engineering best practices, especially in Python; familiarity with production ML practices.
• Founder mindset: ownership + hard work.
• Ready to handle the stress of deploying AI voice agents to thousands of daily phone calls.

MOSAIC FACTOR - Software Engineer

We specialise in developing custom AI algorithms and turning them into robust and scalable software applications for the mobility and logistics sectors.

Education and Experience

• Degree in Computer Science or related field.
• 3+ years of experience in software development, emphasis on back‑end systems.
• Proven experience in real development and production deployment projects.

Core Technical Expertise

• Programming paradigms: solid knowledge of object‑oriented, functional, and other paradigms.
• Languages: professional experience with Java and Python.
• Software architecture: deep knowledge of design patterns, SOLID principles, and scalable architectures.
• APIs and microservices: experience designing and implementing RESTful APIs and distributed architectures.

Front‑End Development (Highly Valued)

• React: practical experience developing user interfaces with React and its ecosystem.
• UI/UX: ability to create intuitive interfaces that handle complex data.

DevOps and Infrastructure

• Containers: experience with Docker and container orchestration.
• CI/CD: knowledge of continuous integration and deployment pipelines.
• Cloud Platforms: familiarity with AWS, GCP or Azure.
• Tools: Git, monitoring systems, observability tools.

AI/ML Knowledge (Differential Plus)

• Fundamental concepts: understanding of ML algorithms and their application.
• Model integration: experience integrating ML models into production applications.
• Generative AI: knowledge of LLMs, RAG, or agent frameworks.
• MLOps: experience in model lifecycle, from development to production monitoring.

What We Offer

• Prediction systems for route optimisation and urban fleet management.
• Data platforms that process mobility information in real‑time.
• AI solutions for sustainable logistics and efficient eCommerce.
• Advanced applications that combine European research with practical implementation.

Professional Growth

• Direct collaboration with international researchers and experts.
• Participation in Horizon Europe projects and innovation initiatives.
• Continuous training in emerging AI technologies and software development.
• Exposure to different domains: automotive, smart cities, green logistics.
• Hybrid mode: Barcelona city center office + remote work.
• Flexible hours to adapt to productivity and work style.
• International team with collaborative and supportive culture.
• Relaxed atmosphere where ideas and technical contributions are valued.

Benefits and Compensation

• Competitive salary according to experience.
• Training budget and participation in technical conferences.
• Flexibility to explore new technologies and innovative approaches.

Back‑End Development

• Design and implement robust and scalable back‑end systems.
• Develop efficient APIs that integrate complex data and AI algorithms.
• Optimize performance of applications handling large data volumes.
• Maintain code quality through best practices, testing, and documentation.

Front‑End Contribution

• Develop intuitive interfaces using React.
• Collaborate in designing user experiences that facilitate decision‑making.
• Integrate front‑end with back‑end systems efficiently and maintainably.

Integration and Deployment

• Implement solutions in high‑availability production environments.
• Manage CI/CD pipelines for automated and secure deployment.
• Monitor production systems and resolve incidents proactively.

Collaboration and Innovation

• Work closely with data scientists to productise research algorithms.
• Participate in defining technical architectures for new projects.
• Contribute technical ideas to improve existing processes and solutions.
• Stay updated on emerging technologies relevant to the domain.

Are you ready to apply your software engineering expertise to projects that truly matter? At MOSAIC Factor you will have the opportunity to work at the intersection of advanced technology and social innovation, developing solutions that contribute to a more sustainable and intelligent future. Join our team and be part of the technological transformation in mobility and logistics.