Senior Backend Developer

Verifone

WHY VERIFONE For more than 30 years Verifone has established a remarkable record of leadership in the electronic payment technology industry. Verifone has one of the leading electronic payment solutions brands and is one of the largest providers of electronic payment systems worldwide. Verifone has a diverse, dynamic and fast paced work environment in which employees are focused on results and have opportunities to excel. We take pride in the fact that we work with leading retailers, merchants, banks, and third party partners to invent and deliver innovative payments solution around the world. We strive for excellence in our products and services, and are obsessed with customer happiness. Across the globe, Verifone employees are leading the payments industry through experience, innovation, and an ambitious spirit. Whether it’s developing the next platform of secure payment systems or searching for new ways to bring electronic payments to new markets, the team at Verifone is dedicated to the success of our customers, partners and investors. It is this passion for innovation that drives each one of our employees for personal and professional success. Verifone is proudly an in-office work culture as we see immense benefits to career development and business results from our colleagues being physically co-located. WHAT'S EXCITING ABOUT THE ROLE We are seeking a Senior Developer based in Lisbon to play a key role in building and evolving Verifone’s next-generation payment and commerce platforms. This is an opportunity to work at the intersection of embedded systems, Android, and high‑performance backend components, contributing to solutions that are used globally at massive scale. In this role, you’ll tackle complex technical challenges across C/C++ and Java, working close to the Android stack (including the HAL layer) and collaborating with experienced engineers to deliver secure, reliable, and high‑quality software. You’ll have real ownership of your work, influencing architecture decisions, enforcing strong coding standards, and helping drive technical excellence across the team. You’ll be hands‑on with modern tools and workflows—Android Studio, Gradle, Linux-based environments, and CI/CD pipelines—while partnering with cross‑functional teams using JIRA, Confluence, Jenkins, and Artifactory. If you enjoy deep technical problem‑solving, writing clean and maintainable code, and seeing your work power real‑world payment experiences, this role offers both impact and growth within a global technology leader. SKILLS AND EXPERIENCE WE DESIRE Core Technical Requirements * Strong experience in C/C++ development * Solid code analysis skills and ability to follow/enforce coding standards * Strong Java experience (mandatory) * Android development experience (HAL layer is a strong advantage) * Kotlin is a plus, but not sufficient on its own Tools & Environment * Experience with Android Studio * Gradle build system knowledge * Familiarity with Linux systems * Experience with JIRA, Confluence, Jenkins, Artifactory (advantage) OUR COMMITMENT Verifone is committed to creating a diverse environment and is proud to be an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status. Verifone is also committed to compliance with all fair employment practices regarding citizenship and immigration status.

Upwork

Upwork Inc.’s (Nasdaq: UPWK) family of companies connects businesses with global, AI-enabled talent across every contingent work type including freelance, fractional, and payrolled. This portfolio includes the Upwork Marketplace, which connects businesses with on-demand access to highly skilled talent across the globe, and Lifted, which provides a purpose-built solution for enterprise organizations to source, contract, manage, and pay talent across the full spectrum of contingent work. From Fortune 100 enterprises to entrepreneurs, businesses rely on Upwork Inc. to find and hire expert talent, leverage AI-powered work solutions, and drive business transformation. With access to professionals spanning more than 10,000 skills across AI & machine learning, software development, sales & marketing, customer support, finance & accounting, and more, the Upwork family of companies enables businesses of all sizes to scale, innovate, and transform their workforces for the age of AI and beyond. Since its founding, Upwork Inc. has facilitated more than $30 billion in total transactions and services as it fulfills its purpose to create opportunity in every era of work. Learn more about the Upwork Marketplace at Upwork.com and follow us on LinkedIn, Facebook, Instagram, TikTok, and X; and learn more about Lifted at Go-Lifted and follow on LinkedIn. ---------------------------------------------------------------------------------------------------------------------------------- As a Senior Software Engineer on the tax engineering team, you will build and improve the services that power tax calculation across VAT, sales tax, and withholding for a global platform. You'll own meaningful pieces of the backend, contribute to frontend workflows, and collaborate closely with engineers, product, finance, and compliance partners to ship reliable, well-tested systems. This is a strong fit for someone who enjoys working through detailed business logic, integrating third-party providers, and steadily raising the quality of complex financial software. RESPONSIBILITIES: * Build, extend, and maintain backend services for tax calculation and payments, focusing on accuracy, reliability, and clean, testable code. * Contribute to frontend workflows using Vue.js or similar modern JavaScript frameworks to support internal tools and customer-facing experiences. * Develop and maintain APIs and integrations with external payment processors and tax engines, improving performance, observability, and error handling. * Partner with product, finance, tax, and compliance stakeholders to translate business and regulatory requirements into well-scoped technical work. * Improve code quality through thoughtful testing, code reviews, and AI-assisted development workflows that increase velocity without sacrificing rigor. * Investigate production issues, identify root causes, and deliver durable fixes that strengthen the reliability of tax and payments systems. WHAT IT TAKES TO CATCH OUR EYE: * Solid backend engineering experience with Java, including building RESTful APIs, working with relational databases, and deploying services on AWS. * Working experience contributing to frontend applications using Vue.js or another modern JavaScript framework. * Track record of owning project-level work end to end and collaborating effectively with cross-functional partners. * Exposure to tax, fintech, payments, or another compliance-heavy domain is a plus, paired with a willingness to learn complex business rules quickly. * Practical fluency with AI-enabled engineering tools such as GitHub Copilot or Cursor, with the judgment to review and validate outputs and a habit of sharing useful AI techniques with teammates. ---------------------------------------------------------------------------------------------------------------------------------- Come change how the world works. Upwork is establishing its first international operational hub in Lisbon, Portugal. The new office is expected to be fully operational by Q4 2026. This role will require 3 days in office once we have an office open. This position will initially be employed through a partner to ensure a seamless hiring process while we establish the hub. Once the hub is established, there may be opportunities to transition to employment with Upwork, depending on business needs and other requirements. While employed by the partner, you’ll work as part of Upwork’s team, with access to our resources, culture, and growth opportunities. Our partner will offer competitive benefits. When Upwork’s hub is established, we will be excited to offer employment and benefits directly as business needs require.  Upwork is committed to building a diverse, inclusive, and equitable workforce. Employment decisions are made without regard to race, color, religion, gender, sexual orientation, gender identity, national origin, disability, or any other status protected by applicable law. We use BrightHire, an AI-enabled tool, to record interviews and summarize interview transcripts. The tool allows the interviewer to focus on the discussion and does not score or evaluate candidates or make recommendations. The interview transcripts are reviewed, and decisions are only made by humans. Candidates who prefer not to have their interview recorded through BrightHire can opt out when the interview is scheduled. To learn more about how Upwork processes and protects your personal information as part of the application process, please review our Global Job Applicant Privacy Notice and the Applicant Privacy Addendum (EEA, UK, and Switzerland). The annual base salary range for this position  is displayed below. The range displayed reflects the minimum and maximum salary for this position, and individual base pay will depend on your skills, qualifications, experience, and location. Additionally, this position is eligible for the annual bonus plan or sales incentive plan and eligibility to participate in our long term equity incentive program. Annual Base Compensation €53.500—€77.000 EUR   To learn more about how Upwork processes and protects your personal information as part of the application process, please review our Global Job Applicant Privacy Notice

Valtech

Why Valtech? We’re the experience innovation company - a trusted partner to the world’s most recognized brands. To our people we offer growth opportunities, a values-driven culture, international careers and the chance to shape the future of experience.  THE OPPORTUNITY At Valtech, you’ll find an environment designed for continuous learning, meaningful impact, and professional growth. Whether you're pioneering new digital solutions, challenging conventional thinking or building the next generation of customer experiences, your work will help transform industries.  We are proud of:  * The work we do and the innovation we drive  * Our values of share, care and dare  * A workplace culture that fosters creativity, diversity and autonomy  * Our borderless, global framework, which enables seamless collaboration  The role   We are looking for an experienced Senior Data Engineer to design, build, and optimize modern, cloud-based data platforms that power analytics, AI, and data products across the organization. Beyond technical delivery, we're looking for someone genuinely curious about the business problems behind the data — someone who can apply common sense thinking, detailed analysis, and experience-based recommendations to help derive and shape business requirements, not just implement them as given. You will work on scalable batch, streaming, and near-real-time pipelines, enabling high-quality, curated datasets while ensuring robust data governance, security, and observability across the data ecosystem. You will also play a key role in supporting AI and GenAI systems, enabling pipelines for machine learning, causal modeling, and LLM-powered applications such as RAG and agent-based systems. Our preferred platforms are Microsoft Azure / Fabric (primary), GCP, AWS, Databricks, and Snowflake, with Azure experience being highly transferable to Fabric. You will collaborate closely with data scientists, ML engineers, and platform teams to ensure the data foundation supports production-grade, decision-oriented AI systems. Role responsibilities Build & Data Platform Engineering Design and implement scalable data platforms and pipelines across cloud environments (Azure/Fabric, AWS, GCP, Databricks, Snowflake). This includes developing reliable batch, streaming, and near-real-time pipelines using technologies such as Spark and Delta Lake, and building ingestion, transformation, and curation workflows for both structured and unstructured data. You will implement modern data architectures including lakehouse patterns and medallion layering (bronze, silver, gold), ensuring systems are reusable, scalable, and aligned with enterprise needs. Enable AI, GenAI & Data Products Deliver high-quality datasets that support analytics, machine learning, causal modeling, and optimization systems. You will enable data pipelines for GenAI use cases (including LLMs, RAG pipelines, and vector-based data flows), as well as agent-based architectures and intelligent workflows, ensuring that data is model-ready and production-grade. Data Modeling, Orchestration & Automation Design scalable logical and physical data models for analytical and operational use cases, ensuring consistency across domains. Orchestrate workflows using tools such as Airflow, dbt, Lakeflow, or equivalents, with strong focus on automation, reliability, and maintainability of end-to-end pipelines. Architecture, Governance & Observability Apply modern architecture patterns including event-driven and streaming architectures, and ensure adherence to best practices in data governance, lineage, quality, and access control (RBAC/ABAC). Establish strong data observability, including monitoring of data freshness, pipeline reliability, and SLA adherence, ensuring systems remain trustworthy and production-ready. Data Serving, Integration & Optimization Enable data serving layers (APIs, feature inputs, analytical endpoints) to support downstream systems, including ML and AI platforms. Continuously monitor and optimize pipelines and infrastructure for performance, scalability, and cost efficiency. Requirements Discovery & Business Partnership Bring genuine curiosity to every engagement — ask the right questions to understand not just what stakeholders are asking for, but why. Apply common sense thinking, detailed analysis, and experience-based recommendations to help derive and refine business requirements, surfacing gaps or better alternatives where they exist rather than simply executing a brief as written. Collaboration Work closely with data scientists, ML engineers, analysts, and business stakeholders to translate requirements into robust data solutions. Support adoption of data products and contribute to best practices across the data and AI ecosystem. Must have qualifications Technical skills Strong hands-on experience with Apache Spark and Delta Lake, and strong programming skills in Python and SQL. Proven experience building batch and streaming data pipelines and production-grade data platforms, with solid understanding of data modeling, data quality, and governance principles. Cloud & Platforms (Key Requirement) Experience with one or more major cloud platforms, with preference for Microsoft Azure / Fabric, as well as AWS or GCP. Familiarity with modern data platforms such as Databricks and Snowflake is expected. Architecture & Systems Thinking Experience with lakehouse architectures and distributed data systems, and strong understanding of scalability, reliability, and performance considerations in data pipelines. Mindset Naturally curious, with strong problem-solving skills focused on scalability and reliability, and a collaborative approach to working in cross-functional teams. Comfortable applying common sense thinking, detailed analysis, and experience-based recommendations to help derive and challenge business requirements rather than taking them at face value. Experience in Agile or consulting environments is beneficial. Nice to have qualifications   Experience with GenAI and AI data systems (e.g., RAG pipelines, vector databases, LLM data preparation), as well as CI/CD for data pipelines and infrastructure-as-code tools such as Terraform, ARM, or CloudFormation.  Additional exposure to streaming technologies (e.g., Kafka), Spark optimization, or advanced analytics and ML workloads (including causal or experimentation platforms) is valuable. Experience building data products or large-scale analytics platforms is also beneficial.  Commitment to reaching all kinds of people  We design experiences that work for all kinds of people - and that starts with our own teams. At Valtech, we’re intentional about building an inclusive culture where everyone feels supported to grow, thrive and achieve their goals. No matter your background, you belong here. Explore our Diversity & Inclusion site to see how we’re creating a more equitable Valtech for all.  THE BENEFITS   This is a position based in Portugal.  Beyond a competitive compensation package, we offer:  * Flexibility, with remote and hybrid work options (country-dependent)  * Career advancement, with international mobility and professional development programs  * Learning and development, with access to cutting-edge tools, training and industry experts  Our benefits are tailored to each location. Your Talent Partner will provide full details during the hiring process.  YOUR APPLICATION PROCESS Once you apply, our Talent Acquisition team will review your application. Your CV should cover key information on relevant experiences and expertise. We do not require information such as age, gender, marital status, or a headshot in your application. We review all candidates based on skills, experience, and potential. ⚠️ Beware of recruitment fraud! We are committed to inclusion and accessibility. If you need reasonable accommodations during the interview process, please either indicate it in your application or let your Talent Partner know.  ABOUT VALTECH Valtech is the experience innovation company that exists to unlock a better way to experience the world. By blending crafts, categories, and cultures, we help brands unlock new value in an increasingly digital world.  At the intersection of data, AI, creativity, and technology, we drive transformation for leading organizations, including L’Oréal, Mars, Audi, P&G, Volkswagen Dolby, and more.  At Valtech, we don’t just talk about transformation. We make it happen. Our people are the heart of our success, and we foster a workplace where everyone has the support to thrive, grow and innovate.  Are you ready to create what’s next? Join us.