Senior Backend Engineer - ComparaJá

Senior Software Engineer (Java)

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

Senior Software Engineer

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.

Senior Backend Developer

Nexxiot

Nexxiot is digitalizing freight asset management with technology that now oversees the world’s most extensive network of connected intermodal containers and railcars. Clients gain access to unparalleled real-time data, which streamlines fleet management and automates logistics processes. Nexxiot devices, built for resilience, withstand extreme conditions and provide long-term, detailed insights into cargo events, including impacts, delays, safety and security incidents, and loading activities. Based in Zurich, Switzerland, Nexxiot’s influence extends globally. Our team, comprised of industry experts, operates from offices in Europe and North America and maintains a presence in a majority of depots, ports, and rail yards. To learn more about how Nexxiot is leading the value generation for the rail industry, please visit www.nexxiot.com. THE ROLE We are an IoT startup turning massive-scale, low-power device data into real-world impact. With a fleet of more than one million connected devices, we generate high-volume telemetry every day. We are looking for a passionate Backend Developer to help enrich, transform and distribute this data in a flexible hybrid setup combining remote and in-office work from our new office in Portugal. You will join an interdisciplinary agile product team and contribute to the design, implementation and operation of distributed backend services. Together with your team, you will build reliable, scalable systems that process large volumes of device data and power customer-facing products. We are looking for someone curious, pragmatic and collaborative who enjoys solving complex problems, automating repetitive tasks, and continuously improving how the team works. YOUR RESPONSIBILITIES * Design and implement backend services, including tests and  technical documentation * Deploy and operate services using CI/CD best practices * Take end-to-end ownership across the full lifecycle: design, implementation, testing, deployment and operations * Monitor services and data streams and respond to anomalies * Provide 3rd-level support and ensure service availability during business hours * Review merge requests and design documents from teammates * Participate in agile software development activities (e.g. planning meetings, reviews, retrospectives…) REQUIREMENTS * 5+ years of professional software development experience * Strong experience with Kotlin or Java * Solid knowledge of backend architecture, distributed systems and API design * Experience with SQL (PostgreSQL) and/or NoSQL (DynamoDB) * Familiarity with messaging systems (Kafka, SQS, SNS) * Experience building and operating containerized services (Docker, Kubernetes, ECS or Fargate) * Solid understanding of software testing (TDD is encouraged but not mandatory) * Curious and never afraid of learning to master new tools, technologies, and methodologies * Fluent in English NICE TO HAVE: * Geospatial data experience * Gradle knowledge * Linux / Unix shell skills Work authorization: Applicants must be legally authorized to work in Portugal. Unfortunately, we are not able to sponsor visas for this role. OUR BACKEND STACK * Kotlin / Java  * Apache Kafka  * SQS  * DynamoDB  * CockroachDB * Gradle * Docker * Kubernetes