[Hiring] Mobile Core Engineer @TextNow, Inc.

Role Description

You've run a mobile core at a carrier and want to do it on a cloud-native platform. You'll be the person on the team who knows what the network is supposed to do: how an attach should flow, why a Diameter or SIP request failed, what a policy rule does to a subscriber's traffic.

You'll work alongside our SRE, who owns the cloud platform, and developers who build the services around the core.

Where you'll work: remote anywhere in the US or Canada, with working hours that overlap Eastern time. You'll travel to our Waterloo office a few times a year to work in the device lab and meet the team, so you need to be able to travel to Canada.

What you'll do

• Operate our converged 4G/5G core: packet core, IMS, HSS/UDM and related network functions.
• Define what we monitor: the alarms, KPIs and thresholds that matter, wired into paging with SRE.
• Own config changes: change plans, rollback criteria and impact analysis, shipped through the change pipeline our SRE runs.
• Validate vendor software in our lab before it reaches production.
• Own capacity and SIMs: subscriber, session and license headroom, SIM management and over-the-air (OTA) updates.
• Lead partner and device onboarding: devices (UE), roaming partners and SIM profiles.
• Lead core incidents: protocol, charging and policy issues. Read the capture, find the cause.
• Lead voice interconnect and roaming signalling: SBCs and SIP trunks, Diameter routing and IPX, and signalling security.
• Keep lawful intercept working with the team, with checks so changes don't break it.
• Work with our vendor on defects, bringing evidence to every escalation and pushing for root causes that hold up.
• Teach the automation what good looks like: turn your network knowledge into runbooks, health checks and investigation steps that AI agents can follow.
• Bring the team up to speed: the SRE and developers all ramp up on the core and share on-call for it with you.
• Use AI across the job: triaging alarms, reading logs and captures, digging through vendor docs, drafting change plans.

Qualifications

• 5+ years operating a live mobile core in production for an operator (carrier, MVNO or MVNE).
• Hands-on EPC/5GC packet core (PGW, SMF, UPF); working knowledge of IMS.
• Working knowledge of policy and charging (PCRF/PCF, OCS, quota enforcement).
• Comfortable reading and dissecting a packet capture end to end.
• You've written and run MOPs, upgrades and maintenance windows in production.
• You've led production incidents.
• Comfortable deciding what "correct" looks like when nobody else knows.
• You don't settle for how things have always been done. You look for better ways to run the network.
• You already use AI to triage, analyze logs and captures, and automate the repetitive parts of operations.

Nice to have

• Alarm correlation or noise reduction on vendor network function alarms, or automated runbooks for core operations.
• Cloud-native network functions on Kubernetes.
• DPI-based traffic classification.
• Onboarding and troubleshooting devices (UE).
• Working with GSMA roaming specs (IR.21, IR.88).
• Python or Go, git, kubectl.

Requirements

• Base Salary Range: $123,900 - $298,800 a year.
• United States (All other areas not listed above): USD $123,900 - $249,000.
• United States (NYC, CT, NJ, Seattle, LA, San Diego): USD $136,300 - $273,900.
• United States (San Francisco / Bay Area): USD $148,700 - $298,800.

Benefits

• Free phone service.
• Strong work life blend.
• Employee stock options.
• Unlimited vacation.
• 12 paid holidays per year.
• Competitive pay.
• Health, dental, and vision benefits.
• Short-term & long-term disability.
• $750 annual wellness benefit or healthcare spending account.
• 401(K) matching.
• Parental leave for eligible employees.
• Learning & Development opportunities.
• Travel for various team events, company-wide off-sites, and more.