Sr Software Engineer

ACI Worldwide · Timişoara

Senior Software Engineer — Support Lead

About the team

The Connetic Account-to-Account organization owns high-value payment processing, instant payment processing and batch payment processing end to end. We move billions of transactions across ACI's network, and this department is directly accountable for the reliability, speed, and quality of that experience. As Senior Software Engineer – Support Lead you will be actively participating in and leading Level 3 Support activities on a cloud-native infrastructure, with AI-assisted engineering practices.

What You'll Own

Deep troubleshooting and root cause analysis for complex issues, such as intermittent failures, performance degradation, data corruption and integration faults
Confirm whether an issue is a defect, a configuration problem or a usage problem. Provide or implement fixes, scripts and data corrections where applicable
Triage, fix and backport security vulnerabilities (including third-party dependency upgrades) within agreed remediation SLAs
Join Priority1/2 (P1/P2) triage incidents, drive the technical diagnosis, and help restore service
Provide clear technical updates to customers, account managers and leadership during incidents, and take part in post-incident reviews
Feed real-world issues back into the roadmap, and push for fixes that reduce ticket volume
Manage the issues backlog, team capacity, support schedule and on-call rotation
Use AI-assisted engineering tools daily — troubleshooting, code generation, review, test authoring, and incident triage
Mentor mid-level and junior engineers, and share what you learn through documentation, demos, or informal coaching
Explain complex technical trade-offs clearly to engineers and non-technical stakeholders alike, and influence decisions with data and rationale

Our Tech Stack

Deep expertise in this exact stack isn’t a hard requirement – strong engineers from adjacent stacks are welcome to apply.

Java — expert-level proficiency: JVM internals, concurrency, performance tuning, Spring Boot / Spring ecosystem, and modern Java (17+) features
Angular — expert-level proficiency: modern Angular (17+) including micro-frontends, performance tuning and secure front-end practices (dependency vulnerability remediation, version upgrades)
Gen AI / LLM tooling — hands-on experience with LLM APIs (OpenAI, Anthropic, or equivalent), prompt/workflow design, RAG patterns, and AI coding assistants (Copilot, Cursor, Claude Code, or equivalent) as part of daily development
Low-latency systems — demonstrated experience designing and optimizing transaction processing, payments, or equivalent high-throughput distributed systems
Microservices & APIs — RESTful and event-driven service design; experience with API versioning, backward compatibility, and contract testing
Containers & Kubernetes — familiarity with containerizing applications and running them on Kubernetes (AKS, EKS, GKE, or OpenShift)
Cloud platforms — Azure; working familiarity AWS a strong plus

and/or

What You Bring

You don't need to check every box below to apply — if most of this resonates, we want to hear from you.

5+ years of professional software engineering experience, with a track record of owning complex features or systems from design through production
Hands-on experience in production support, ideally at Level 3 — troubleshooting live incidents, performing root cause analysis, delivering code fixes (including security vulnerability remediation), and working under SLA and on-call pressure
Experience diagnosing production issues using logs, metrics and tracing tools, and working with ticketing/incident systems
Strong critical thinking — you frame decisions clearly, weigh explicit trade-offs rather than defaulting to the familiar option, and adjust your thinking as new information comes in, especially under pressure or ambiguity
Strong systems thinking — you reason about how components interact and where failure or complexity will emerge upstream and downstream, not just within the piece you're touching
Solid grounding in SaaS and cloud-native fundamentals — the underlying principles, not just familiarity with the tools, even where our own infrastructure is still catching up to them
Genuine curiosity — you ask why, you're not satisfied with 'it works,' and you bring creative approaches to problems that don't have an obvious answer yet
Working knowledge of secure coding practices, threat modeling, and access-control design
Comfortable using AI-assisted development tools as a daily practice
Solid grounding in distributed systems, event-driven architecture, and microservices at meaningful scale
Strong technical communication — able to mentor other engineers and influence direction without needing formal authority

Bonus Points

Experience in payments, fintech, banking, or another regulated industry
Experience with real-time, low-latency, or high-availability systems
Experience embedding AI/ML models directly into customer-facing product features (prompt/workflow design, RAG, evaluation pipelines)
Exposure to internal platform or infrastructure engineering work
A track record of technical writing, conference talks, or open-source contribution
Experience conducting technical interviews or contributing to hiring

What We Offer

Technically challenging work on a platform processing mission-critical payment transactions for financial institutions worldwide
Be part of a truly global product development organization — real centers of engineering excellence spread across multiple regions, organized around product families and technical capabilities rather than geography for its own sake, with engineers everywhere shaping our core products and technical direction
A cloud-native, automation-first engineering culture that treats quality, security, and developer experience as competitive advantages, not compliance checkboxes
Real career growth — ACI actively develops engineers into senior technical leaders and engineering managers; your trajectory here is yours to define
An AI-native team that embraces modern tooling and gives engineers real latitude to experiment, improve, and lead
Competitive compensation and benefits
Hybrid model — typically 2–3 days in-office across ACI's global hub locations
L3 production support rotation, shared across the team – the escalation path for incidents that couldn’t be resolved by earlier support tiers
Some domestic and international travel (5–10%) as needed for customer or cross-team engagements

Equal Opportunity & Compliance

ACI Worldwide is an Equal Opportunity Employer; all qualified applicants are considered without regard to race, color, religion, gender, gender identity, sexual orientation, national origin, genetics, disability, age, or veteran status. This role requires adherence to ACI's Code of Business Conduct and Ethics, and — given access to sensitive payment data — compliance with applicable security and data-protection standards (PCI-DSS, SOC 2, GDPR, CCPA). Comprehensive background screening is required. Responsibilities may evolve with business needs.

Req ID 20139

LI-GI1

LI-Hybrid

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