Spectron: network orchestration in practice at scale; what works, what hurts#

Katarzyna Kurowska & Aldrin Isaac — eBay (Senior Software Engineer; Director, Site Network Engineering & Security)

• Why: The single most relevant talk for physical DC fabric work: how a hyperscale-adjacent operator designs, provisions, and validates diverse DC topologies with an in-house intent-based system — including a candid "what hurts" section, which is rarer and more useful than the wins.
• What: Spectron is eBay's spec-driven, intent-based fabric orchestration covering the ZTP lifecycle: fabric planning, spec generation, rack/TOR power-on, and deployment. Engineers write JSON topology specs (site, IP spec, node/interface specs for spines/leaves); the system renders device config, validates against a digital twin, and deploys. Multi-vendor, with explicit SONiC support. The "what hurts" half is the real value: abstractions that came out too generic or too limiting, prototypes that silently became production code, and SONiC's promise of a unified software stack across interchangeable hardware colliding with per-vendor functionality and API discrepancies.
• How: Layered, composable abstractions — Layout (NodeSpec + InterfaceSpec), IP addressing (IPSpec + IPAllocationSpec), routing (RoutingSpec), and fungible hardware via PlatformSpec + NodeProfile — with rendering decoupled from generation and renderers composed from reusable blocks. GNS3-based topology emulation verifies before production deploy. A custom schema language and model generator keep it extensible; an adapter principle absorbs multi-vendor SONiC differences.
• Where applicable: eBay-specific build, but the architecture lessons (define your domain early, design around primitives, embed NetEng in the dev cycle, early verification at every lifecycle stage) transfer to any operator building or buying fabric automation. Future work listed: EVPN/VXLAN overlay, test/Day-2 framework, traffic filters, HA/scalability — worth tracking if you have adjacency with the team.