Technical Support Engineer specializing in Alternative Payment Methods (APM)

About the Position

Technical Support Engineer specializing in Alternative Payment Methods (APM)

Belgrade, Serbia

On-site

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About Unlimit

Unlimit is a global fintech ecosystem built to eliminate financial borders holding businesses back. The company provides the extensive infrastructure needed to scale globally, integrating payment processing, multi-currency business accounts, BaaS, and crypto gateways into a single, intelligent platform.

Across 17 offices globally, Unlimit bridges hyper-local expertise with a high-capacity financial network, giving companies the agility to expand across regions with operational confidence and speed. Driving the evolution of payments, Unlimit is transforming its infrastructure from human-operated fintech into AI-native financial infrastructure - where APIs are consumed by machines, integrations are negotiated by agents, and systems evolve continuously through intelligent automation. Our next users are not only humans. They are AI agents acting on behalf of humans and businesses.

Unlimit serves more than the needs of businesses today; we are building the nervous system for a borderless global economy.

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Role Overview

The Technical Support Engineer specializing in Alternative Payment Methods (APM) is a critical technical role responsible for the stability, performance, and reliability of all APM integrations within our PSP/fintech ecosystem.

This engineer acts as the top-tier technical expert for merchants, internal Product/Engineering teams, and external payment partners. The primary focus is on resolving complex incidents, driving deep root-cause analysis (RCA), leading operational improvements, and guaranteeing seamless, high-volume transaction processing for all supported APMs.

Success in this role requires advanced technical proficiency, superior analytical skills, and the ability to articulate complex issues clearly to both technical and non-technical audiences.

As Unlimit evolves toward AI-native financial infrastructure, this role will also leverage intelligent monitoring, automation, and AI-assisted operational workflows to detect anomalies faster, improve incident response, and continuously enhance the reliability of payment integrations.

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Responsibilities

1. Expert Incident & Problem Management

• Serve as the highest escalation point for all critical APM-related issues across production and sandbox environments.
• Conduct in-depth troubleshooting of complex transaction failures, including authorization declines, settlement discrepancies, callback issues, and routing problems.
• Perform real-time analysis using logging and monitoring tools (Kibana, Datadog, Grafana, Splunk) to quickly diagnose system anomalies and errors.
• Coordinate incident resolution efforts with Engineering and DevOps, focusing on swift mitigation and long-term recurrence prevention.
• Lead emergency response protocols during major outages impacting APM transaction flows.
• Execute deep-dive Post-Incident Root Cause Analysis (RCA) and present findings to Product and Engineering teams.

2. APM Performance & Monitoring

• Develop, maintain, and optimize monitoring dashboards, alerts, and system health checks specific to APMs.
• Analyze key performance indicators (KPIs) such as success rates, latency, and drop-off rates to identify and propose systemic improvements.
• Drive proactive detection initiatives to flag merchant-level or provider-level processing issues before they escalate into incidents.

3. Integration & Merchant Support

• Provide senior-level technical consultation to merchants integrating various APMs (e.g., Pix, Sofort, iDeal, Klarna, local wallets).
• Review and validate API specifications, payload structures, webhook configurations, and authentication mechanisms.
• Assist with integration test scenarios and required APM certification processes.

4. Operational Excellence & Automation

• Propose and drive solution implementations (automation, tooling, configuration changes, or product enhancements) to reduce recurring incidents and operational friction.
• Create and maintain comprehensive documentation, including detailed runbooks, troubleshooting guides, and standard operational procedures.
• Promote operational excellence through standardization and knowledge sharing.

5. Cross-Functional Collaboration

• Serve as the technical APM subject matter expert for Product Managers, Engineering, Compliance, and Partner Management teams.
• Provide support insights that influence product backlog prioritization and roadmap decisions.
• Articulate APM-specific technical constraints, regional nuances, and compliance requirements to internal stakeholders.

6. External Partner Liaison

• Act as the primary technical point of contact with APM providers and acquirers.
• Manage and escalate persistent technical issues, ensuring adherence to partner SLAs.
• Validate the impact of provider updates, maintenance schedules, and API changes on our merchant base.

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Requirements

Required Skills & Experience

• Payment Systems: Deep, hands-on understanding of payment processing workflows, specifically APM models and related regional payment regulations.
• APIs & Data: Proven experience with REST APIs, webhooks, JSON, and authentication protocols.
• Monitoring & Logging: Proficiency with enterprise-grade monitoring and logging systems (Datadog, Grafana, Kibana, ELK Stack, Splunk).
• Data Analysis: Strong proficiency in SQL for complex transactional data analysis.
• Coding: Ability to read and debug code snippets (e.g., Python, Node.js, Java).
• AI-driven mindset: Strong AI-driven mindset and curiosity about emerging AI technologies.
• Hands-on experience: Experience using AI tools (e.g., LLMs, automation frameworks, AI-assisted development tools) to enhance productivity or system performance.

Professional Experience

• 4–7+ years in a senior technical support, payments engineering, or integration engineering role.
• Essential: Prior experience within a high-volume PSP, fintech, or banking environment is strongly preferred.
• Experience supporting global payment methods and managing high-traffic systems.

Key Competencies

• Exceptional problem-solving, analytical, and critical-thinking abilities.
• Outstanding written and verbal communication, capable of distilling complex technical concepts.
• Demonstrated ability to remain calm and effective while managing critical incidents under pressure.
• High sense of ownership, bias for action, and commitment to operational improvements.

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We Offer

• Competitive salary
• Opportunity to work in a dynamic and innovative fintech environment
• Professional growth and development opportunities
• Collaborative and inclusive work culture

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About the Company

Unlimit is an equal opportunity employer. We believe passionately that employing a diverse workforce is central to our success. We make recruiting decisions based on your experience and skills. We welcome applications from all members of society irrespective of age, sex, disability, sexual orientation, race, religion or belief.

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses and identifying potential inconsistencies or verification signals in application materials based on available information. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.

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Join Unlimit Team now!