Performance Testing

Bucharest

This is Worldline.

Worldline helps businesses of all shapes and sizes to accelerate their growth journey - quickly, simply, and securely. We are the innovators at the heart of the payments technology industry, shaping how the world pays and gets paid. Our technology powers the growth of millions of businesses across 5 continents. And just as we help our customers accelerate their business, we are committed to helping our people accelerate their careers. Together, we shape the evolution.

The Opportunity

The Core Foundation & Integration Tribe (CFI) implements and delivers the Card Issuing core applications, from Card Issuing lifecycle to Transactions clearing & settlement to hundred of banks. With over 150 million cards and 1.16 billion monthly transactions, our platforms operate at the forefront of capacity and performance.

We are looking for an engineer to be the architect and guardian of our Card issuing solutions performance and reliability.

This is a strategic, hands-on engineering role for someone obsessed with making large-scale distributed systems fast, resilient, and efficient by design. You will be the technical cornerstone of our platform's stability, with the mandate to influence architecture, write code, and solve the most complex performance puzzles.

Day-to-Day Responsibilities

• Review critical solution designs and veto architectures that present unmitigated performance or reliability risks.
• Architect and operate our centralized performance and load testing platform, providing it as a self-service to our development squads.
• Design and lead our most critical end-to-end performance tests and Chaos Engineering to find system weaknesses before our customers do.
• Analyze long-term performance metrics (SLOs) to identify slow regressions and silent bottlenecks, and drive their resolution before they become incidents
• Lead war rooms for performance incidents, using advanced tools (profilers, distributed tracing) to diagnose systemic root causes.
• Recommend solution and prototype fixes, optimize critical code paths, and demonstrate the solution to development teams
• Liaise with the SRE and operations teams of our internal and external clients, building deep technical credibility.

Who Are We Looking For

We look for big thinkers. People who can drive positive change, step up and show what’s next – people with passion, can-do attitude and a hunger to learn and grow. In practice, this means:

• 5+ years of proven experience with deep, hands-on expertise in a language like Java, or Python, legacy and public cloud (GCP, AWS) knowledge.
• You are obsessed with how large-scale distributed systems interact. You think in terms of concurrency, queuing, caching, consistency, and failure modes.
• Your expertise covers the full spectrum of modern communication patterns: from synchronous, high-throughput API-driven interactions, to decoupled and resilient event-driven architectures (Kafka), and the reliability of large-scale batch processing
• Crucially, you know precisely when to use each pattern to trade off speed, consistency, and throughput
• Expertise in technical domains : Application Performance Monitoring, Databasee performance optimization (Oracle, PostgreSQL), network analysis, low-level system performance
• Your arguments are backed by metrics, traces, and logs. Your motto is "Data over opinions." You are an expert in monitoring tools like Prometheus, Grafana, and distributed tracing
• You lead through your technical credibility and your ability to dive deep into the code to solve the most complex problems. This is not a PowerPoint-and-meetings role
• You excel at explaining complex technical concepts in simple terms and have a proven ability to mentor and influence senior engineers across multiple teams.
• You have a strong sense of ownership and accountability, with a bias for action and a focus on delivering measurable improvements in reliability and performance
• Full professional proficiency in English is required for our international environment.

Perks & Benefits

In addition to joining a global leader in payments, you can also expect an excellent range of benefits. These include a rewarding salary, leave days, an attractive pension scheme, global learning days and many more. We also have location specific benefits, varying from private medical insurance, to extended parental leave and a flexible benefits scheme, allowing you to purchase discounted products and services.

If you join us, you will enjoy:

• Hybrid Working Policy
• Gift vouchers on the occasion of Christmas/Easter Holidays
• Free private medical services
• 21 vacation days/year
• Referral bonuses for new hires recommended by you
• WFH & Flexible Working Hours
• Full access to the “Learning” platform

What’s more, we really value Innovation, Cooperation, Excellence and Empowerment. These values are reflected on our daily work. This is the core of our organization. At Worldline our top priority is to engage, encourage and develop you to help you improve your potential. In fact, we have comprehensive training and development programs in place demonstrating our dedication to developing your career.

Our success comes from strong skills, new insights, diverse points of view and the energy of all employees at Worldline. Not only do they represent the Heart and Face of our company, they are also key players in our success. We make leading our talents a major asset in the success of our business.

Worldline is proud to be an Equal Opportunity employer. We do not discriminate based upon race, religion, colour, national origin, sex (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender identity, gender expression, age, status as an individual with a disability, or other applicable legally protected characteristics.

Shape the evolution.

We are on an exciting journey towards the next frontiers of payments technology, and we look for big thinkers, people with passion, can-do attitude and a hunger to learn and grow. Here you’ll work with ambitious colleagues from around the world, take on unique challenges as a team, and make a real impact on the society. With an empowering culture, strong technology and extensive training opportunities, we help you accelerate your career - wherever you decide to go. Join our global team of 18,000 innovators and shape a tomorrow that is yours to own.

Learn more about life at Worldline at jobs.worldline.com

We are proud to be an Equal Opportunity employer. We do not discriminate based upon race, religion, color, national origin, sex (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender identity, gender expression, age, status as an individual with a disability, or any applicable legally protected characteristics.