SIM Engineer

About Telnyx

Telnyx is an industry leader thats not just imagining the future of global connectivitywere building it. From architecting and amplifying the reach of a private global multi-cloud IP network to bringing hyperlocal edge technology right to your fingertips through intuitive APIs were shaping a new era of seamless interconnection between people devices and applications.

Were driven by a desire to transform and modernize whats antiquated automate the manual and solve real-world problems through innovative connectivity solutions. As a testament to our success were proud to stand as a financially stable and profitable company. Our robust profitability allows us not only to invest in pioneering technologies but also to foster an environment of continuous learning and growth for our team.

Our collective vision is a world where borderless connectivity fuels limitless innovation. By joining us you can be part of laying the foundations for this interconnected future. Were currently seeking passionate individuals who are excited about the opportunity to contribute to an industry-shaping company while growing their own skills and careers.

About you

Were looking for a Junior SIM Engineer with a technical background and a drive to specialize in SIM and eUICC engineering. Youre organized detail-oriented and genuinely curious about how SIMs work from profile structures and file systems to eSIM provisioning and OTA updates. Youre comfortable with scripting and automation and you see AI as a productivity multiplier whether thats automating repetitive tasks generating documentation or building internal tooling.

The opportunity

Youll join the Mobile Core Services squad responsible for subscriber identity & authentication core network services and subscriber data & policy across the Telnyx wireless network. Youll work on the technical foundations of our SIM and eSIM product learning from a senior SIM engineer while contributing to day-to-day operations profile management and new feature delivery.

Telnyx operates as a global MVNO/MVNE provisioning millions of SIMs across multiple profile vendors and eSIM platforms. Youll learn the SIM lifecycle end-to-end while building real expertise in a niche high-value domain.

Responsibilities

Support SIM/eSIM profile creation and management across multiple vendor platforms
Assist with eSIM DP operations: profile download activation and lifecycle management
Perform and validate OTA updates for SIM applets and file structures
Manage SIM logistics: ordering fulfillment stock tracking and shipment coordination
Support BAP (Baseline Application Profile) creation and maintenance
Troubleshoot SIM-related issues reported by customers or internal teams
Maintain documentation for SIM processes configurations and vendor procedures
Coordinate with Mobile Platform Engineering on HSS/subscription provisioning
Assist with testing and validation of new SIM features before production rollout

What were looking for

1 year in telecom IT or a related technical field (internship experience counts)
Understanding of SIM/UICC fundamentals: file systems (EF/DF structures) applets USIM/ISIM
Basic familiarity with at least one SIM profile creation tool or vendor platform
Willingness to learn eSIM and Remote SIM Provisioning standards (GSMA SGP.22 SGP.32)
Organized and detail-oriented SIM logistics and profile management require accuracy
Comfortable with scripting or automation (Python Bash or similar)
Strong written communication for documentation and cross-team coordination
Interest in using AI tools to enhance productivity automating tasks generating docs analyzing logs or building tooling

Bonus points

Experience with eSIM DP platforms or RSP systems (SMDP/SMDS)
Familiarity with Java Card or SIM applet development
Understanding of OTA update mechanisms (SCP02 SCP03 SCP80 SCP81)
Knowledge of GlobalPlatform for secure element lifecycle management
Understanding of LTE/5G network attach and SIM authentication (AKA EPS-AKA)
Experience with SIM management systems (OTAAP SMSC)
Experience building AI-assisted workflows (LLM-powered tooling copilots automated reporting)

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