Support-bot orchestration
- for
- Mercado Libre
- when
- 2021–22
- Problem
- A support-bot prompt that was getting worse as it grew.
- My contribution
- Built the model integration and orchestration backend, routing structured LLM intents to internal services and integrating it across consuming teams. Informal tech lead alongside two senior developers.
- Decision
- Stop growing one prompt. Split it into retrieval, reclassification and answering; let the model ask for information in a structured form and the backend fetch it; hand off to a person when the bot can't help.
- Delivered
- Split into retrieval, reclassification and answering, with human escalation.
- Result
- About 25% of support handling steps were bot-handled, as reported by the manager and in performance reviews.
- Status
- production · 2021–22
≈25%of support handling steps
what I foundEvaluations showed the prompt regressing as it grew.
what I foundFailures included malformed structured output, internal information requests reaching customers and more hallucinations.
- You are a support assistant.
- Answer in the customer's language.
- If the order is late, explain the carrier states.
- If the customer asks for a refund, apply the policy.
- If the message is unclear, ask one question.
- If unsure, hand over to a person.
evals flag regressions as the prompt grows
- retrieval
- reclassification
- answering
try it
Where a conversation ends up
Bot answers. The bot had what it needed and answered.
invented messages, illustrative routingcontrol
The model never called the services
- customer → interface
1The customer writes a message
- interface → backend
2The interface forwards it
- backend → model
3The backend asks the model
- model → backend
4The model returns a structured request for information
- backend
5The backend fetches the internal information
- backend → model
6The backend hands the information to the model
- backend → interface
7The backend routes the answer back
- interface → customer
8The answer reaches the customer
The backend is the controller: it reads the model's structured request, fetches the information and routes the response.
evaluations
What the evaluations flagged
- Malformed structureThe model's structured output stopped being well formed.
- Internal requests leakingInternal information requests reached customers.
- More hallucinationsInvented answers became more frequent as the prompt grew.
The fix: split the prompt into retrieval, reclassification, answering, with human escalation.
counting
How a step is counted
One conversation, counted step by step
- Bot answers the first questionbot+1 = 1
- Bot answers a follow-upbot+1 = 2
- Bot reclassifies the conversationbot+1 = 3
- A person resolves ithuman+1 = 4
Total: 4 steps. Bot and human handling count alike.
invented conversation, illustrativeadoption
The shared interface, used widely
- Mercado Libre
- Pago
- Shops
- Envíos
- other teams
ecosystem adoption, not a counted census
ownership
Who did what, and when
- evals show regressions
- prompt split in stages
- human escalation
- adopted across the ecosystem
- MeOrchestration, model integration, API backend foundation and integrations into consuming teams; informal technical lead
- Two senior developersAlongside me
- ColleaguesThe shared microfrontend and additional ticket operations
- Evaluation designWritten by others; I ran them
What shipped
Evaluations caught the regressions. The fix was structure, not a longer prompt.
- Colleagues' shared customer-experience microfrontend was adopted across Mercado Libre, Pago, Shops, Envíos and other teams before I left.
Method and caveats
The 25% counts handling steps, not tickets, and carries no time-savings measure.
- Models, evaluation dataset, traffic and rollout percentages: not available