SIM Engineer

O firmie

Our client designs, builds, and operates dedicated, private mobile core networks for enterprises. Their service enables other companies to deploy their own connectivity products and services without needing to become full-fledged telecommunications operators.

Opis stanowiska

Our client designs, builds, and operates dedicated, private mobile core networks for enterprises. Their service enables other companies to deploy their own connectivity products and services without needing to become full-fledged telecommunications operators.

SIM Engineer

We offer:

Responsibilities:

• First 3 months:
  • Learn the current SIM/eSIM architecture, customer profiles, IMSI sponsor model, vendor platforms, and release process.
  • Review and validate USIM, ISIM, and application configurations, including service tables, PLMN files, branding files, IMS parameters, and security settings.
  • Understand the current Multi-IMSI logic: triggers, timers, IMSI selection, pointer behavior, fallback, error handling, and OTA interaction.
  • Execute controlled laboratory and field tests covering attachment, IMSI switching, roaming, voice, SMS, data, VoLTE, Wi-Fi Calling, and device behavior.
  • Support entitlement-server and carrier-bundle validation for Android and Apple devices.
  • Take ownership of selected defects and configuration changes through analysis, implementation, retest, and release evidence.
• Ongoing responsibilities:
  • Create and maintain SIM/eSIM profile specifications for customer launches, changes, and production batches.
  • Configure and validate Multi-IMSI applet parameters, IMSI mappings, PLMN lists, triggers, timers, priorities, pointer logic, fallback behavior, and recovery scenarios.
  • Own day-to-day SIM and eSIM provisioning operations, including profile creation and configuration, SIM/eSIM inventory management, SM-DP+ operations, activation/download troubleshooting, profile lifecycle management, production batch processing, and reconciliation across SIM/eSIM platforms, BSS and HSS/UDM.
  • Plan and execute BAP validation, personalization-data checks, and release acceptance with SIM vendors.
  • Manage and validate subscriber provisioning data including ICCID, IMSI, MSISDN associations, authentication/security parameters, IMSI sponsor mappings and customer-specific SIM/eSIM profile configurations.
  • Prepare, execute, and troubleshoot OTA campaigns.
  • Support entitlement-server integration in line with GSMA TS.43.
  • Support Android carrier configuration enablement and Apple carrier-bundle onboarding and validation.
  • Analyze SIM traces, APDU logs, modem logs, network captures, OTA reports, and device behavior to isolate problems across SIM, device, radio, core network, and backend systems.
  • Coordinate technical actions with SIM, OTA and SM-DP+ vendors, entitlement suppliers, core-network teams, device vendors, and customer stakeholders.
  • Maintain specifications, configuration baselines, test plans, traceability, release records, troubleshooting guides, and operational runbooks.

Requirements:

• 3-5 years of practical experience in SIM/eSIM engineering
• Practical understanding of Multi-IMSI solutions, IMSI selection and switching, network-selection behavior, timers, fallback, prohibited PLMNs, and failure recovery.
• Experience creating and reviewing SIM/eSIM profile requirements and validating personalized cards or downloadable profiles.
• Working knowledge of OTA architecture and operations, including APDU scripting, campaign validation, secure channels and troubleshooting.
• Experience building structured test scenarios and analyzing APDU traces, modem/device logs, PCAPs, and network registration failures.
• Familiarity with relevant ETSI, 3GPP, and GSMA specifications and the ability to convert standards into implementable requirements and expected results.
• Clear written and spoken English, disciplined documentation, and confidence working directly with vendors and cross-functional teams.
• Direct experience with a commercial Multi-IMSI applet.
• Knowledge of GSMA TS.43 entitlement services.
• Android carrier enablement experience using AOSP.
• Experience supporting Apple carrier-bundle setup.
• Knowledge of SIM security and provisioning data, including Milenage, K/OPc, OTA keys, transport keys, key exchange, and HSS dependencies.

Additional advantages:

• Atractive salary (b2b contract)
• Fully remote work

We kindly inform you that we will only respond to selected applications.

TeamQuest has been added to the register of entities conducting employment agencies by the Marshal of the Mazowieckie Voivodship under the number 11118.

Requirements

Requirements:

• 3-5 years of practical experience in SIM/eSIM engineering
• Practical understanding of Multi-IMSI solutions, IMSI selection and switching, network-selection behavior, timers, fallback, prohibited PLMNs, and failure recovery.
• Experience creating and reviewing SIM/eSIM profile requirements and validating personalized cards or downloadable profiles.
• Working knowledge of OTA architecture and operations, including APDU scripting, campaign validation, secure channels and troubleshooting.
• Experience building structured test scenarios and analyzing APDU traces, modem/device logs, PCAPs, and network registration failures.
• Familiarity with relevant ETSI, 3GPP, and GSMA specifications and the ability to convert standards into implementable requirements and expected results.
• Clear written and spoken English, disciplined documentation, and confidence working directly with vendors and cross-functional teams.
• Direct experience with a commercial Multi-IMSI applet.
• Knowledge of GSMA TS.43 entitlement services.
• Android carrier enablement experience using AOSP.
• Experience supporting Apple carrier-bundle setup.
• Knowledge of SIM security and provisioning data, including Milenage, K/OPc, OTA keys, transport keys, key exchange, and HSS dependencies.

Additional advantages:

• Atractive salary (b2b contract)
• Fully remote work

We offer

We offer:

Responsibilities:

• First 3 months:
  • Learn the current SIM/eSIM architecture, customer profiles, IMSI sponsor model, vendor platforms, and release process.
  • Review and validate USIM, ISIM, and application configurations, including service tables, PLMN files, branding files, IMS parameters, and security settings.
  • Understand the current Multi-IMSI logic: triggers, timers, IMSI selection, pointer behavior, fallback, error handling, and OTA interaction.
  • Execute controlled laboratory and field tests covering attachment, IMSI switching, roaming, voice, SMS, data, VoLTE, Wi-Fi Calling, and device behavior.
  • Support entitlement-server and carrier-bundle validation for Android and Apple devices.
  • Take ownership of selected defects and configuration changes through analysis, implementation, retest, and release evidence.
• Ongoing responsibilities:
  • Create and maintain SIM/eSIM profile specifications for customer launches, changes, and production batches.
  • Configure and validate Multi-IMSI applet parameters, IMSI mappings, PLMN lists, triggers, timers, priorities, pointer logic, fallback behavior, and recovery scenarios.
  • Own day-to-day SIM and eSIM provisioning operations, including profile creation and configuration, SIM/eSIM inventory management, SM-DP+ operations, activation/download troubleshooting, profile lifecycle management, production batch processing, and reconciliation across SIM/eSIM platforms, BSS and HSS/UDM.
  • Plan and execute BAP validation, personalization-data checks, and release acceptance with SIM vendors.
  • Manage and validate subscriber provisioning data including ICCID, IMSI, MSISDN associations, authentication/security parameters, IMSI sponsor mappings and customer-specific SIM/eSIM profile configurations.
  • Prepare, execute, and troubleshoot OTA campaigns.
  • Support entitlement-server integration in line with GSMA TS.43.
  • Support Android carrier configuration enablement and Apple carrier-bundle onboarding and validation.
  • Analyze SIM traces, APDU logs, modem logs, network captures, OTA reports, and device behavior to isolate problems across SIM, device, radio, core network, and backend systems.
  • Coordinate technical actions with SIM, OTA and SM-DP+ vendors, entitlement suppliers, core-network teams, device vendors, and customer stakeholders.
  • Maintain specifications, configuration baselines, test plans, traceability, release records, troubleshooting guides, and operational runbooks.