I build AI systems that give small teams their hours back.
I'm Justin Stewart, an engineer and former engineering manager. Cierto Tech is my one-person studio, so the person you talk to is the person who builds it.
140 hours per month
- Copy data between spreadsheetsConnects directly to the ad platforms
- Rebuild a format for every clientWarehouses the data in one place
- Write summaries by handGenerates client-ready narratives
- Miss the deadline every cycleDelivers through each client's channel
Reduced monthly client reporting time from 140 hours to 14–21 hours for a performance marketing agency.
- OpenAI API
- Anthropic Claude
- Cursor
- Warp
- Next.js
- Vercel
- Supabase
- Tailwind CSS
- DaisyUI
- GitHub
- n8n
- Make
- Meta Ads Manager
- Notion
- Calendly
- One-Time Secret
- Kit (ConvertKit)
- Kit
Four ways to work with me
Prompts & Skills
Free
The prompts, Claude skills, and playbooks I use on real client work. Take them and run them yourself.
Browse the libraryAutomation Audit
1 week, $2,500–$5,000
I find the workflow costing you the most hours and show you what automating it is worth.
See the auditProduction Readiness Audit
1 week, $2,500–$5,000
You built it with AI and people want it. I tell you what breaks with real users and real money.
See the auditBuild and maintain
Priced after an audit
I build what the audit found, then keep it running on a monthly retainer.
Start a Project
Your business running better with less manual work.
Need more than one person?
If your project needs a full team, I'll tell you. Toptal is where I'd hire, and I'm on the network myself.
Referral link. I may earn a fee if you hire through it.
Proof
Founder notes
Read all notes- Automate Weekly Client ReportingPlaybook, 8 min
- Automate Meta Ads MonitoringPlaybook, 7 min
- How to decide whether a workflow is worth automatingComing soon
Tell me what's slowing your team down.
Or what you're trying to build. I'll reply within one business day with a clear next step.
Start a Project