White-Label AI & Backend Engineering for Agencies
AI & API Integration Engineer
I help agencies and SaaS teams ship complex AI and API integrations without hiring another senior backend engineer.
Sound familiar?
- A client wants an integration that's outside your team's current skillset.
- An automation built in Zapier/Make/n8n has become too fragile or complex to maintain.
- An AI prototype impressed a client but needs real production backend work before it ships.
- A client wants AI connected to their private business data — safely.
- An OAuth/API implementation is blocking a project from moving forward.
- Backend reliability is becoming a support burden on something you shipped fast.
What I handle
- →AI integrations — tool calling, structured output, RAG over private data
- →Backend services & REST/SOAP API integrations
- →OAuth / OIDC / JWT implementation
- →Webhook processing systems
- →Production hardening — retries, timeouts, fallbacks, validation
- →Debugging & fixing fragile production systems
- →Docker & deployment
How it works
- 1
Send requirements
Whatever you have — a client brief, a Slack thread, a half-built prototype.
- 2
Technical assessment
A straight, fast read on feasibility and approach — usually within 1-2 business days, no charge.
- 3
Fixed-scope pilot
A clearly scoped, fixed-price engagement so both sides know exactly what's being delivered.
- 4
Delivery
Tested, documented, deployed — with a clean handoff, not a black box.
- 5
Optional ongoing partnership
If it's a fit on both sides, a bounded monthly retainer for recurring technical capacity.
Proof, not promises
Two live, interactive demos — authenticated tool-calling AI agents over data, structured output validation, retries/ timeouts, and the kind of production hardening most AI prototypes skip. Both run on synthetic/mock data — no real customer or company data is involved.
Demo 1 — AI Support Integration
An authenticated agent answers account-specific customer questions by calling real internal tools, with validated structured output and audit logging.
Try the live demo →
Demo 2 — Agency Automation
Lead → enrichment → AI qualification → CRM update → personalized response — the pattern behind most agency automation offers, built as real, testable code.
Try the live demo →
Background
- •Senior backend engineer — Java, Spring Boot, distributed systems
- •Production experience in banking / financial systems, where correctness and security aren't optional
- •Extensive background in external API integrations — REST, SOAP, OAuth/OIDC/JWT
- •Comfortable owning production debugging under real pressure, not just greenfield builds
Have a project like this?
Send me the requirements and I'll give you a straight read on approach and scope — no charge for that first look.
Email javiersivack@gmail.com