Staff Fiber Network Engineer

Staff Fiber Network Engineer

Anthropic is building Anternet — a private, global dark-fiber backbone connecting our data centers, cloud regions, and partners. We light our own glass: long-haul and metro DWDM over leased dark fiber and IRU pairs terminating on our own optical line systems and routers.

We're looking for a Staff Fiber Network Engineer to own the physical layer of this network end-to-end. You'll be the person who decides where the fiber goes and then makes sure it actually shows up, splices clean, and tests to spec. This is equal parts route engineering, vendor management, and field-delivery program management — the connective tissue between "we need N×Tbps between these two metros" and "the span is lit and carrying traffic."

This is a foundational role building Anternet's fiber program from the ground up. You'll define the inventory system, set acceptance standards, and establish the vendor bench yourself.

You'll work closely with our optical/transport engineers (who design the line systems on top of your fiber), our backbone routing team, and our data center and capacity planning teams.

Key Responsibilities

• Route engineering and design — Plan terrestrial fiber routes between Anternet PoPs and data centers. Evaluate diversity (SRLG, conduit, ROW, landing-station separation), latency, and OSNR/loss budgets. Produce route KMZs, splice diagrams, and as-built documentation
• Fiber acquisition — Source and qualify dark fiber, IRU, and wavelength options from carriers and infrastructure providers. Run RFPs, compare bids on cost, route quality, diversity, and MTTR, and drive contracts to signature alongside legal and procurement
• Vendor and delivery management — Own the build from PO to acceptance: track splicing, lateral construction, building entries, meet-me-room cross-connects, and CLS access. Hold vendors to schedule and SLA; serve as the escalation point when a span is late or fails OTDR
• Acceptance and characterization — Define and enforce fiber acceptance criteria (OTDR bi-directional, IL/ORL, CD/PMD where relevant). Review test results, reject substandard spans, and sign off on handover to the optical team
• Capacity and lifecycle management — Maintain the source-of-truth fiber inventory (strands, conduits, splice points, leases, IRU terms and renewals). Forecast fiber needs against our PoP and capacity roadmap. Monitor degradation and quality over time
• Operations — Partner with NOC and field-ops on fiber cuts, locates, and repairs. Drive root-cause analysis with vendors and feed lessons back into route-diversity decisions

Minimum Qualifications

• Experience in OSP/fiber planning or network delivery at a carrier, hyperscaler, dark-fiber provider, or large enterprise backbone
• Demonstrated experience taking long-haul or metro dark-fiber routes from design through acceptance — can read an OTDR trace and engage substantively with vendors on splice quality
• Solid working knowledge of the vendor landscape: who has conduit where, how IRU vs. lease vs. wavelength pricing behaves, and what's negotiable in an MSA
• Proficiency with GIS/KMZ tooling for route design and comfort maintaining structured inventory data
• Sufficient understanding of optical transport (DWDM, amplifier spacing, span loss, CD/PMD) to design fiber that line-system engineers can use
• Ability to serve as the single accountable owner for physical delivery across many concurrent builds

Preferred Qualifications

• 8+ years of OSP/fiber planning or network delivery experience
• Experience standing up a fiber program from near-zero — building the inventory system, acceptance standards, and vendor bench from scratch
• Familiarity with permitting, ROW, and make-ready processes in US metro markets
• Scripting or light tooling experience (Python, Go, SQL, or similar) for inventory and reporting workflows
• Comfort with occasional travel for site surveys, CLS/ILA walks, and vendor meetings

Logistics

Minimum education: Bachelor's degree or an equivalent combination of education, training, and/or experience

Required field of study: A field relevant to the role as demonstrated through coursework, training, or professional experience

Minimum years of experience: Years of experience required will correlate with the internal job level requirements for the position

Location-based hybrid policy: Currently, we expect all staff to be in one of our offices at least 25% of the time. However, some roles may require more time in our offices.

Visa sponsorship: We do sponsor visas! However, we aren't able to successfully sponsor visas for every role and every candidate. But if we make you an offer, we will make every reasonable effort to get you a visa, and we retain an immigration lawyer to help with this.

We encourage you to apply even if you do not believe you meet every single qualification. Not all strong candidates will meet every single qualification as listed. Research shows that people who identify as being from underrepresented groups are more prone to experiencing imposter syndrome and doubting the strength of their candidacy, so we urge you not to exclude yourself prematurely and to submit an application if you're interested in this work. We think AI systems like the ones we're building have enormous social and ethical implications. We think this makes representation even more important, and we strive to include a range of diverse perspectives on our team.

Your safety matters to us. To protect yourself from potential scams, remember that Anthropic recruiters only contact you from @anthropic.com email addresses. In some cases, we may partner with vetted recruiting agencies who will identify themselves as working on behalf of Anthropic. Be cautious of emails from other domains. Legitimate Anthropic recruiters will never ask for money, fees, or banking information before your first day. If you're ever unsure about a communication, don't click any links—visit anthropic.com/careers directly for confirmed position openings.

How We're Different

We believe that the highest-impact AI research will be big science. At Anthropic we work as a single cohesive team on just a few large-scale research efforts. And we value impact — advancing our long-term goals of steerable, trustworthy AI — rather than work on smaller and more specific puzzles. We view AI research as an empirical science, which has as much in common with physics and biology as with traditional efforts in computer science. We're an extremely collaborative group, and we host frequent research discussions to ensure that we are pursuing the highest-impact work at any given time. As such, we greatly value communication skills.

The easiest way to understand our research directions is to read our recent research. This research continues many of the directions our team worked on prior to Anthropic, including: GPT-3, Circuit-Based Interpretability, Multimodal Neurons, Scaling Laws, AI & Compute, Concrete Problems in AI Safety, and Learning from Human Preferences.

Come Work With Us!

Anthropic is a public benefit corporation headquartered in San Francisco. We offer competitive compensation and benefits, optional equity donation matching, generous vacation and parental leave, flexible working hours, and a lovely office space in which to collaborate with colleagues. Guidance on Candidates' AI Usage: Learn about our policy for using AI in our application process.