02 Problem reframing
The evident problem was tool fragmentation
Before Inference Insights, a model incident brought model owners, data on-calls, and infrastructure engineers into a shared document. They pasted screenshots and links from custom notebooks, dashboards, and command-line tools—often ten to fifteen per investigation. With no shared timeline or terminology, evidence had to be correlated by hand.
The deeper problem was an absent investigation model
Foundational interviews and usage analysis, reinforced by ongoing feedback and product data, revealed that consolidating dashboards would not solve the deeper issue. Engineers lacked a coherent investigation model that preserved context across tools and handoffs, and made the path from symptom to cause understandable to every responder.
They needed to trace a symptom through the model version, input signals, upstream data, and training process while retaining direct access for experts. The work became a shared operating model across teams, not another observability surface.
Expertise was unevenly distributed
Experienced on-calls carried the tribal knowledge that helped them move quickly; newer responders had to reconstruct it during an incident. The platform needed to meet both where they were:
03 Building alignment
Working as the connective layer
Within Meta’s Prediction Robustness program, I was the only designer dedicated to the platform. I connected the core product team with the on-call users, model owners, infrastructure partners, design peers, and leaders whose decisions shaped the investigation experience.
Research as a continuous operating loop
Research moved through Understand ⇆ Ideate ⇆ Validate ⇆ Iterate as a continuous loop. Before launch, interviews and existing-tool usage mapped how investigations unfolded and where engineers lost context. I turned those findings into competing concepts, then tested clickable prototypes with the same users.
After launch, product usage and direct feedback fed the next cycle, shaping immediate fixes and later releases.
“Now the flow and interface is intuitive enough that doesn’t require too much domain knowledge to use.”
— ML engineer and ongoing customer partner, 2023
04 Designing the system
1
- Identified focused analysis phase to test (Feature upstream traceability)
- Rolled out alpha to users in under 1 quarter
- Validated core value
- Secured leadership backing /Unlocked formal investment
2
- Transparent, traceable investigation stages/ visual investigation flow
- Investigation guidance
- 1-2 investigators are able to complete investigation in hours instead of days.
3
- Minutes to root cause for many use-cases
- Unlocked deeper layers of investigation ie. model parameters/ model internal states (MIS)
- Complex cases remain reviewable
4
- Formalized into a modular component based platform
- Self-serviceable/ customizable workflows, user onboarded metrics and analyzers
- Broader adoption
- Fewer bespoke customer solutions
05 Scaling outcomes
In its public engineering account, Meta reported that HawkEye helped cut production debugging time by an order of magnitude in its first two years. It also reported a several-orders-of-magnitude reduction in the time from triage to isolating relevant serving inputs. The toolkit supported recommendation and ranking models across multiple Meta products, while guided exploration let less experienced responders investigate complex problems with less reliance on specialists.
The fourth outcome was organizational. A shared investigation model reduced reliance on tribal knowledge, while self-service patterns let partner teams bring in new needs without routing every addition through the founding group. Over time, the platform no longer needed a standing dedicated team. It scaled by absorbing work the team would otherwise have had to keep doing.
Debugging velocity
Order-of-magnitude improvements*
Critical investigations condensed from days to hours
Root cause isolation
Days of searching, cut to a fraction*
Engineers could trace a bad model to the inputs behind it far faster.
Guided triage
One investigation, two ways through
Guidance made complex triage less expert-dependent.
Self-serve @ scale
Removed the “founding team” bottleneck
New capabilities and workflows no longer required a standing team.
* Published outcomes: Meta Engineering, “AI debugging at Meta with HawkEye” (2023). Business impact and fourth panel: Robin’s account. Illustrations are not to scale; exact internal metrics cannot be shared.

