Support Engineer

About the role

You will operate at the intersection of payments infrastructure and emerging AI automation, owning critical escalations that keep global transactions flowing without interruption. The role demands precise diagnosis of card processing events while you translate complex system logs into clear operational insights for both technical and non-technical stakeholders. You will be responsible for maintaining the stability of in-house card-processing environments, ensuring that authorization and clearing operations meet strict uptime and recovery standards. You will partner closely with the Card Processing engineering teams to escalate intricate issues and drive them toward permanent resolution. Furthermore, you will configure and manage test and pre-production emulators that replicate live payment rails for validation and training purposes. This position is central to the evolution of our infrastructure, moving from human-operated workflows toward AI-native systems where intelligent agents handle routine monitoring and remediation. You will play a key role in supporting the next generation of users, which increasingly include AI agents acting on behalf of businesses. Ultimately, your work will directly support Unlimit's mission to build the nervous system for a borderless global economy.

Key facts

What you'll do

Investigate and resolve high-severity incidents in card processing systems by analyzing system logs through Splunk, CloudWatch, or DataDog to identify root causes.

Monitor the in-house card-processing platform in real time, interpreting system events and transaction flows to detect anomalies before they impact customers.

Communicate effectively with client support representatives via Slack to gather context, provide updates, and coordinate responses during critical outages.

Escalate complex technical issues to the Card Processing engineering team, ensuring all relevant data and transaction traces are included for swift resolution.

Configure and maintain emulators for payment systems to build robust test and pre-production environments that accurately mirror live behavior.

Automate repetitive operational tasks such as file exchanges, scheduled job execution, and log analysis using scripting and automation tools, including AI-driven automation where applicable.

Process and prioritize reverse tasks received from internal teams, ensuring that reversals and adjustments follow regulatory and operational guidelines.

Utilize PL/SQL to write and refine simple CRUD queries that extract transaction data, verify account states, and support diagnostic procedures.

Leverage API browsers like Postman and Swagger to inspect, test, and validate payment endpoints and system integrations during troubleshooting.

Contribute to the continuous improvement of operational runbooks by documenting procedures, refining checklists, and incorporating lessons from incident post-mortems.

Requirements

You must bring at least one year of hands-on experience supporting card processing systems, or two years of experience with any payment processing platforms.

You must demonstrate a solid understanding of the authorization and clearing stages within card processing operations, including settlement and dispute fundamentals.

You must have practical experience with logging and monitoring systems such as Splunk, CloudWatch, DataDog, or similar observability tools.

You must be proficient in the HTTP protocol as used at the application layer and comfortable interacting with APIs through browsers like Postman and Swagger.

You must have the ability to write basic PL/SQL queries for CRUD operations to retrieve and manipulate data in relational databases.

You must be able to work effectively in a fast-paced, high-responsibility environment where payment integrity and uptime are critical.

You must be comfortable following detailed procedures and escalating findings in a structured manner to ensure consistent issue resolution.

You must possess strong analytical skills to correlate system events, logs, and transaction traces to identify patterns that indicate failure modes.

Nice to have

Experience with Core Banking Systems, particularly Temenos, would provide valuable context for payment flows and settlement cycles.

Hands-on background with KYC or KYB platforms such as SumSub would help streamline verification-related escalations.

Any familiarity with SmartVista or similar banking infrastructure tools would accelerate diagnostics and configuration tasks.

Experience with Banking as a Service products aligns well with Unlimit's API-first, platform-driven product model.

Practical use of Salesforce for ticketing or client management would enhance cross-functional collaboration and case tracking.

Practical notes

The position is based in Belgrade and operates on a standard full-time schedule. There may be occasional travel requirements as operational needs dictate. No specific visa sponsorship details are provided in this listing. The role is subject to ongoing operational demands, including system updates and incident response outside standard business hours when required.