Mobile Core Engineer, Carrier

TextNow, Inc.; United States; Hybrid; CAD 158,000 - 248,000; Full time

Benefits offered by this job

Free phone service

Employee stock options

Unlimited vacation

12 paid holidays per year

Health, dental, and vision benefits

RRSP matching (Canada)

Parental leave

Disability insurance

Wellness account

Job summary

TextNow is seeking a senior network engineer to own and operate the converged 4G/5G core in a cloud-native environment. You’ll work with SRE and developers to shape monitoring, changes, and incidents for a carrier-grade network.

This remote role covers US/Canada with some travel to Waterloo for the device lab, and requires 5+ years in production core operation, EPC/5GC expertise, and policy/charging know-how. Emphasis on automation and vendor collaboration.

Qualifications

• 5+ years operating a live mobile core in production for an operator.
• Hands-on EPC/5GC packet core (PGW, SMF, UPF) with IMS knowledge.
• Experience with policy and charging (PCRF/PCF, OCS).
• Ability to read packet captures end-to-end.

Responsibilities

• Operate converged 4G/5G core including packet core, IMS, HSS/UDM.
• Define alarms, KPIs, and thresholds with SRE.
• Own config changes and change pipeline.
• Validate vendor software in lab before production.
• Manage capacity, SIMs, OTA updates.
• Lead device onboarding, roaming partners, and SIM profiles.
• Lead core incidents and diagnose causes.
• Lead voice interconnect and roaming signalling (SBCs, SIP trunks, Diameter, IPX).
• Keep lawful intercept working with the team.
• Collaborate with vendor on defects and root causes.
• Teach automation with runbooks and health checks.
• Mentor team and set core direction.

Skills

Live mobile core operation

EPC/5GC packet core

IMS knowledge

Policy & charging

Packet capture analysis

AI-assisted ops

Tools

SBCs

SIP trunks

Diameter routing

Kubernetes

Job description

TextNow is a full MVNO. We run our own converged 4G/5G mobile core in AWS for hundreds of thousands of subscribers, growing toward millions, and we're growing the team that owns and evolves it. AI is built into how this team works: it's how a small team operates, triages and changes a network this size.

About the role

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. You'll learn the parts that are new to you and lead the area.
• 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, so fraud and spoofed signalling get caught early. You'll learn the parts that are new to you.
• 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. Lead on core alarm correlation, config change auditing and unusual call or data session patterns.
• Bring the team up to speed. The SRE and developers all ramp up on the core and share on-call for it with you. You set the direction for the core, and the team shares the load.
• Use AI across the job: triaging alarms, reading logs and captures, digging through vendor docs, drafting change plans.

Who you are

• 5+ years operating a live mobile core in production for an operator (carrier, MVNO or MVNE). Vendor experience counts if you were on call for a customer's live network
• 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, even when "that's how carriers do it" is the easy answer
• 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

Base Salary Range

The expected base salary range for this role is:

Canada Senior: CAD $158,000 – 207,000 annually

Canada Staff: CAD $200,400 – 248,000 annually

Our salary ranges aredeterminedby role, level, and location. Within the range, individual pay isdeterminedby job-related skills, experience, and relevant education or training.

Our goal is to offer a competitive package that reflects the impact andexpertiseyou bring to the team.

This posting is for a current, active vacancy.

More about TextNow

Our culture

We’reproudof the culture thatwe’vebuilt atTextNow,but one of the mostcommon questionswe hear is ‘how do you continue to sustain it as the world and the company continues to change?’ The reality is that we’re only able to keep up because each and everyTextNoviancontributes to our culture throughbeing involved, by living our values, sharing feedback, embracingchangeand more!

Our values

Customer Obsessed

We strive to have a deep understanding of our customers.

Do RightByOur People

We treat each other with fairness, respect, and integrity.

Accept the Challenge

We adopt a "Yes, We Can" mindset to achieve ambitious goals.

Act Like an Owner

We treat this company like it'sour own... because it is!

Give a Damn

We are deeply committed and passionate about our work and achieving results.

Our benefits and more

Free phone service

Employeestockoptions

Unlimited vacation

12 paid holidaysper year

Competitive pay

Health,dental, and visionbenefits

Short-term & long-term disability

$750 annual wellness benefitor healthcare spending account

RRSP matching (Canada)

Parental leavefor eligible employees

We travel a few times a year for various team events,company-wideoff-sites, and more

More information about our total rewards package will be available during the hiring process.

Dogfooding & Customer Obsession

AtTextNow, every employee gets to actively use our app for calling and texting. Dogfooding helps us experience what customers do, to spot issues early, and drive better design, developer, and user experiences.

Diversity and Inclusion

Our aim is to make every person who joinsTextNowfeel like they belong, thatthey’revalued, and thatthey’reable to be their authenticselvesat work.

We’reall accountable for creating an inclusive culture and a sense of belongingforone another. By doing this together,we’llmakeTextNowbetter for everyone.

Equal opportunity

We are an equal opportunity employer and are committed to creating an inclusive environment for all employees. We consider all qualified applicants without regard to race, color, religion, sex, gender identity or expression, sexual orientation, age, disability, or any other protected characteristic.

Applicants who require reasonable accommodation during the hiring process may contact ourTalent Team.

AI usage: We use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses. 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 our Talent Team.

TextNowCandidate Policy

Bysubmittingan application toTextNow, you agree to the collection, use, and disclosure of your personal informationin accordance withthe TextNow Candidate Policy