Join Twilio as a Principal Software Engineer to enhance the quality of global carrier connections through innovative testing and observability systems.
Posted by employer 1 day ago
First seen on Joblaze 2 hours ago
Last verified on the company career page 2 hours ago
What you'll build
- Design and deliver components of carrier test and observability platform
- Build high-throughput data and alerting systems
- Extend and harden production LLM systems
- Diagnose cross-boundary failures
- Contribute to technical design and review
Must have
- 12+ years of software engineering experience
- Deep expertise in distributed systems
- Hands-on experience with LLM-based systems
- Strong proficiency in at least one backend language
- Fluency with event streaming and cloud infrastructure
- Ability to communicate complex technical trade-offs
Nice to have
- Experience with telecommunications, messaging, or voice systems
- Experience with active network testing
- Experience with agentic systems
AI in the day-to-day
Engineers are extending and hardening production LLM systems for automated carrier troubleshooting.
Requirements
- Experience
- 12+ years
Not disclosed in this posting: compensation, visa sponsorship.
Benefits
Joblaze summary
In this role, the Principal Software Engineer at Twilio focuses on enhancing the systems that monitor and assure the quality of global carrier connections for voice and messaging. The position requires extensive experience with distributed systems, high-volume data processing, and LLM-based systems, along with proficiency in backend languages like Java or Go. Ideal candidates are seasoned engineers with a strong background in telecommunications or network testing, capable of mentoring others and contributing to technical design discussions. The team operates in a remote-first environment, emphasizing collaboration and innovation.
Joblaze insights
- Listed today — first seen on Joblaze October 1, 2026. Last confirmed on Twilio's careers page October 1, 2026.
Quick facts
- Is the Principal, Software Engineer (L5) role remote?
- Yes — Twilio lists this as a fully remote position.
- How much experience is required?
- At least 12 years of relevant experience for this Principal, Software Engineer (L5) role.
- What's the tech stack?
- Joblaze extracted these technologies from the posting: AWS, Go, Java, Kafka, Kubernetes, Scala.
- What seniority level is this role?
- Twilio targets principal-level candidates for this position.
- Is this full-time or contract?
- Full-time for this Principal, Software Engineer (L5) role at Twilio.
From the original posting
Who we are
See yourself at Twilio
Join the team as Twilio’s next Principal Software Engineer.
About the job
This position is needed to raise the technical depth of the systems that continuously test, measure, and assure the quality of Twilio's global carrier connections, and the operational platforms that Super Network's operations depend on.
Every call and message Twilio makes crosses a carrier network we don't control. This team is how we know those connections are healthy. We monitor and test them continuously, worldwide, for both voice and messaging reliability, and we build what our operations teams use to act on what we find. Increasingly that means LLM agents troubleshooting carrier problems without a human involved — and that's the part we most want to push further.
Responsibilities
In this role, you’ll:
- Design and deliver major components of Twilio's carrier test and observability platform, covering active voice and messaging testing, quality scoring, and global test coverage.
- Build high-throughput data and alerting systems that turn the data into signals operations teams can act on without drowning in noise.
- Extend and harden our production LLM systems for automated carrier troubleshooting — expanding the classes of issue they resolve without human intervention, and owning the evaluation, observability, and guardrails that make autonomous action safe.
- Diagnose cross-boundary failures where test results, carrier behavior, and platform telemetry disagree, and establish the observability needed to tell those cases apart.
- Contribute to technical design and review across the team, mentor engineers, and help shape written standards that outlast any single project.
*Required:
- 12+ years of software engineering experience, including significant time at staff or principal level working on systems at large scale.
- Deep expertise designing, operating, and debugging distributed systems that ingest and process high-volume time-series or event data in production, including alerting, anomaly detection, and failure isolation.
- Hands-on experience taking LLM-based systems to production and keeping them there: context and tool design, evaluation against real outcomes, cost and latency management, and the guardrails required when model output triggers real actions rather than just producing text.
- Strong proficiency in at least one backend language used at scale (Java, Go, Scala, or similar) and fluency with event streaming and cloud infrastructure (Kafka, AWS, Kubernetes).
- Ability to communicate complex technical trade-offs clearly in writing and to influence peers through design review rather than authority.
Desired:
- Experience with telecommunications, messaging, or voice systems
- Experience with active network testing, monitoring, or quality-of-service measurement.
- Experience with agentic systems that take action on live infrastructure, and with the evaluation practices that make that trustworthy.
Location
This role will be remote, and based in Ireland.
Twilio thinks big. Do you?
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.Standard company text repeated across Twilio's postings is omitted here.
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