David Dominguez
I architect LLM systems that cut inference costs 12x
— and scale to 800K+ users.
Senior AI Engineer · LLM Agents & RAG
Bogotá, Colombia · Open to relocation · Remote (UTC-5)
Experience
Closer AI/ Bogotá
- Cost Cut
- 12x
- No Human Needed
- 75%
- Eval Pass Rate
- 87%
Sept 2025 — Present
Co-founder & CTO
Pre-seed AI sales-agent startup answering end customers on WhatsApp through Meta integrations for 15 paying B2B clients, about 10,000 messages a day at no more than $0.01 per message. Architected a custom multi-agent runtime instead of LangGraph: a state machine that reads intent and journey stage on every turn, scopes prompt, MCP tools and model to that step, calls catalog, payment and memory tools, and hands off to humans only when needed — 75% of conversations never need one. Cut cost per conversation from $0.25 to $0.02 (12x) with per-step routing across 20+ providers, built hybrid multimodal RAG over client catalogs, and grew an eval harness from zero prior data — about 1,000 questions scored by an LLM judge, plus live A/B tests of prompts and models — that took the pass rate from 43% to 87% and gates every release. LLM calls go through PII redaction and zero-retention endpoints. Lead 10 engineers, report to the investors, and still write the core code in TypeScript/Node.js and Python on AWS Bedrock, GCP, Cloudflare Workers, Supabase and Vercel.
MercadoLibre/ Bogotá
- Users Scaled
- 800K+
- Uptime Held
- 99.9%
- Attributed Revenue
- 1%
May 2024 — Sept 2025
Technical Lead
Led the 10-engineer team behind the Affiliates program at Latin America’s largest e-commerce company (NASDAQ: MELI), on Java/Spring Boot microservices, MySQL and React/TypeScript, owning system design, core architecture, sprint delivery and team growth. Scaled it from its first user to 800K+ users in 16 months, reaching 1% of MercadoLibre’s global revenue (attributed), with 99.9% uptime and zero SLA breaches through 800x growth after moving peak-load work to queues and async jobs and adding availability and performance monitoring. Set the team’s testing bar — JUnit and Jest unit and integration suites plus E2E tests gating deploys in CI — and introduced LLM tooling across the team: AI code review on pull requests, LLM-generated unit and integration tests, an internal LLM assistant and AI coding tools for every engineer.
Agua/ Bogotá
- Users
- 1M+
- Infra Cost
- ~$0
- Client-Side
- 100%
Aug 2022 — May 2024
Co-founder & CTO
Co-founded an angel-funded low-code visual app builder, owning its engineering, hiring, budget and roadmap until winding it down in May 2024, and scaled it to 1M+ users at near-zero infrastructure cost by running it fully client-side, with zero data egress. Built an in-browser bundler and compiler that fetched npm dependencies inside the browser and showed the real React output in the editor, kept fast with WebAssembly, caching and regression tests.
Mr. Pink/ Bogotá
- Engineers Led
- 6
- Faster Setup
- 2x
- Team Adoption
- 100%
Aug 2021 — Aug 2022
Lead Developer
Built client web apps for the agency, then led 6 engineers on its largest account, REEF Technology, a US-based multi-billion-dollar company, after convincing its CTO to hire the agency. Built an automated Kubernetes and CI/CD scaffolding platform that halved project setup time with 100% team adoption, earning the promotion from Senior Developer to Lead Developer in Dec 2021.
Credibanco/ Bogotá
- Dev Pool
- 10x
- Terminals
- 1000s
- Junior → Senior
- 10mo
Feb 2020 — Aug 2021
Senior Web Developer
Built software for one of Colombia’s largest card-payment networks (about 400K terminals). Its proprietary POS hardware required C, so built a Python-to-C transpiler that opened terminal development to the company’s Python developers (10x dev pool), then led the rollout to thousands of payment terminals. Grew from Junior Developer to Web Developer to Senior Web Developer in 10 months.
Freelance/ Bogotá
- Clients
- 10+
- To Production
- MVP
- Core Stack
- 3
Oct 2018 — Feb 2020
Software Developer
Built Node.js, React and React Native apps for 10+ clients, from MVPs to production platforms — the full-stack depth behind later architecture work at scale.
Work
- 01Closer AIAI sales agent that closes pipeline while you sleep[AGT-001]2025
- 02LLM Rate LimiterHard spending limits across every AI provider — zero infrastructure[LIB-001]2025
- 03LLM Markdown WhatsAppShip AI on WhatsApp in one function call[LIB-002]2025
- 04OpenFlowOpen-source builder for agent-powered SaaS[PLT-002]2025
- 05AguaA low-code IDE built on near-zero infrastructure spend[PLT-001]2023
- 06MercadoLibreMercadoLibre’s Affiliates program — from first user to 800K, 1% of global revenue (attributed)[SCL-001]2024
- 07Credibanco POSTurned a 10-person bottleneck into a platform hundreds could build on[SYS-001]2021
- 08K8s Scaffolding PlatformEliminated the hidden tax every engineer paid on every new project[DEV-001]2021
- 01[AGT-001]2025
Closer AI
AI sales agent that closes pipeline while you sleep
- Cost Cut
- 12x
- No Human Needed
- 75%
- Response
- <1s
Built a custom multi-agent runtime from zero: an LLM-driven state machine that reads intent and journey stage on every message with embedding-based intent classification, injects only that step’s prompt and MCP tools, keeps cross-session memory, and routes each step to a cheaper or smarter model — GPT-4o mini, Claude Opus, Gemini Flash Lite, Grok 4, Llama 3.1 8B, Qwen or DeepSeek, among 20+ providers. Structured outputs, guardrails, prompt caching, streaming, fallbacks and spend caps keep it at $0.02 per conversation instead of $0.25 (12x) with sub-second p95 turns, tracked on per-client cost dashboards. Retrieval is hybrid multimodal RAG over client catalogs — LLM-aware chunking, BM25 plus Vertex AI multimodal embeddings on Upstash Vector, and GCP reranking — so product search covers text and images, with GCP message queues wiring the pipelines. It handles 75% of customer conversations without a human for 15 paying B2B clients, and an eval harness took the pass rate from 43% to 87%.
- TypeScript
- Python
- LLM Routing
- RAG
- 02[LIB-001]2025
LLM Rate Limiter
Hard spending limits across every AI provider — zero infrastructure
- Extra Infra
- 0
- Overages
- $0
- Provider
- Multi
Built a TypeScript library that enforces hard spending and usage caps across multiple AI providers — preventing budget overruns before they happen. Supports automatic failover to backup models when limits are hit and recycles unused capacity in real time. Drop-in installation, no servers required. Currently in production at Closer AI and open-sourced.
- TypeScript
- Node.js
- Redis
- LLM APIs
- 03[LIB-002]2025
LLM Markdown WhatsApp
Ship AI on WhatsApp in one function call
- Function Call
- 1
- Config
- 0
- Per Integration
- 2-3d
Built a zero-configuration TypeScript library that converts raw AI output into properly formatted WhatsApp messages — handling lists, product cards, links, and Spanish punctuation automatically. One function call replaces days of custom formatting work per integration.
- TypeScript
- Node.js
- NLP
- 04[PLT-002]2025
OpenFlow
Open-source builder for agent-powered SaaS
- Test Files
- 225
- Tenant
- Multi
- Open Source
- OSS
Built a multi-tenant platform for building agent-powered SaaS products: a visual agent builder in Next.js and React, Node.js services on Postgres and Redis, and event-driven scheduled jobs. Every pull request runs format, lint, typecheck and 225 Jest test files in CI. Open source and separate from Closer AI.
- Next.js
- Node.js
- Postgres
- Redis
- 05[PLT-001]2023
Agua
A low-code IDE built on near-zero infrastructure spend
- Users
- 1M+
- Infra Cost
- ~$0
- Servers
- 0
Architected the client-side IDE for a low-code platform from the ground up, including an in-browser bundler and compiler that fetched npm dependencies inside the browser and showed the real React output in the editor, kept fast with WebAssembly, caching and regression tests. The fully client-side architecture took the platform to 1M+ users while keeping infrastructure spend near zero.
- React
- TypeScript
- WebAssembly
- Compiler
- 06[SCL-001]2024
MercadoLibre
MercadoLibre’s Affiliates program — from first user to 800K, 1% of global revenue (attributed)
- Users
- 800K
- Engineers
- 10
- SLA Breaches
- 0
Led a 10-person engineering team building MercadoLibre’s Affiliates program on Java/Spring Boot microservices through its full growth phase — from first user to 800K. The program grew to contribute 1% of MercadoLibre’s global revenue (attributed). Owned system design under real growth pressure: queues and async jobs for peak load, observability, reliability thresholds. Zero SLA breaches across 16 months of 800x growth.
- Java
- Spring Boot
- MySQL
- React
- 07[SYS-001]2021
Credibanco POS
Turned a 10-person bottleneck into a platform hundreds could build on
- Dev Pool
- 10x
- Terminals
- 1000s
- Deploy
- Nationwide
Built a Python-to-C transpiler that opened POS terminal development from a small C-specialist team to the company’s broader developer base. Deployed across thousands of payment terminals nationwide. The transpiler removed a structural hiring and knowledge bottleneck that had been limiting the company’s hardware roadmap for years.
- Python
- C
- Embedded
- Jenkins
- 08[DEV-001]2021
K8s Scaffolding Platform
Eliminated the hidden tax every engineer paid on every new project
- Faster Setup
- 2x
- Manual Steps
- 0
- Team Adoption
- 100%
Identified that engineers were rebuilding identical scaffolding from scratch on every client engagement. Designed and built an automated Kubernetes-based platform that cut setup time in half and standardized delivery quality across the full engineering team.
- Kubernetes
- Docker
- Node.js
- CI/CD
Education
Universidad de los Andes/ Bogotá
Jan 2018 — Dec 2022
Computer Science & Software Engineering (B.S.)
- QS Top 200 Worldwide
- #1 in Colombia
- Top 10 Latin America
- ABET Accredited
My Philosophy
- 01
Adoption is an engineering problem.
The hardest tools to adopt are the ones that ignore how people already work. I build to fit existing workflows, existing habits, existing mental models — because the hidden cost of software is never the license. It’s the change management, the resistance, the workarounds your team builds around tools they were told to use.
- 02
Speed is a strategy. Waiting is a decision.
Every week a tool isn’t in production is a week your team is working around the problem instead of past it. I optimize for sustainable velocity — scoped releases, real users, real feedback — without sacrificing reliability. The compounding cost of delay is invisible until it isn’t. But so is the cost of shipping something that breaks trust.
- 03
Privacy is a design constraint, not an afterthought.
I treat data privacy as an architectural decision, not a compliance checkbox. At Agua, the fully client-side architecture meant zero data egress — both a product requirement and a privacy guarantee. At Closer AI, I face the inverse problem: third-party LLM calls are inherently data-leaving events. Privacy there means governing what leaves, where it goes, and how long it’s retained: PII redaction before provider calls, zero-retention endpoints, and routing by data sensitivity. The approach changes with the problem. The discipline doesn’t.
Stack
TypeScript
primary language, 8 years deep
React
complex UIs, production-grade
Node.js
APIs at scale, low overhead
JavaScript
browser and Node.js
REST APIs
service contracts at scale
Jest
full coverage, fast feedback
MySQL
relational data, query optimization
Python
AI/ML pipelines, data processing
Java
high-throughput backends
PostgreSQL
relational core of the agent platform
CI/CD
automated pipelines, daily deploys
MongoDB
flexible data models, aggregation
Kubernetes
zero-downtime, auto-heals
Sentry
error tracking
Docker
containerized everything
AWS
production infra, auto-scaled
GCP
ML pipelines, Vertex AI
Terraform
infrastructure as code
Datadog
metrics and alerting
AI Agents
multi-agent runtimes, MCP tools
React Native
iOS + Android, one codebase
LLM Routing
right model, right cost
Generative AI
LLM products in production
RAG
hybrid multimodal retrieval
Evals
LLM-as-judge, release gating
Prompt Engineering
per-step prompts, structured outputs
Tool Calling
multi-step agent workflows
MCP
tools injected per step
Machine Learning
embedding-based intent classification
GitHub Actions
CI on every pull request

Contact
David Dominguez
8+ years in software engineering and building production AI agents since 2024, as a hands-on co-founder and CTO who still writes the core code. Native Spanish, English at C2. Open to senior AI engineering roles, remote with full US time-zone overlap (UTC-5) or with relocation. If you are building LLM agents that have to work in production at a sane cost, this is a conversation worth having.
l.david.dominguez.12@gmail.com