Clarityfrom day one.
I’m Theodor Diaconu, software founder and hands-on architect. I help teams take AI and ambitious software from idea to production. The critical work I do personally; senior engineers from Cult of Coders join when a build needs more hands.
01Problems
Problems worth bringing to Day1
If one of these sounds familiar, the conversation is short.
Pilots that never ship
AI demos exist. None is trusted with production traffic.
A decision without an owner
Build versus buy has circulated for months. Nobody senior has time to call it.
The platform bill keeps growing
The system gets slower and more expensive. Every fix on the table is a guess.
An idea bigger than your team
You know what you want to build. You need someone who has built it before.
02Ways to work together
Ways to work together
Three engagement models, each led personally by Theo, with a small senior Cult of Coders team when the build needs one.
03Work
Selected work
The constraint, who did what, and the measured result.
Anonymized SEO software client
Analytics that outran the data warehouse
SEO query metrics at a scale the managed cloud warehouse couldn’t serve — slow exactly where the product needed speed, and expensive everywhere.
Architecture and technology selection by Theo; implementation by senior Cult of Coders engineers.
ResultA custom analytics platform roughly 50× faster than the BigQuery it replaced, with infrastructure spend down more than 80%.
Anonymized financial-technology client
Payment operations you can actually see
A multi-currency payment system processing real volume with poor visibility: delays surfaced late, approvals lived in inboxes.
System design for monitoring and approvals by Theo; implementation by senior Cult of Coders engineers.
ResultProcessing time down 20%; payment delays down by more than half.
Anonymized legal-technology client, Germany
Multi-tenant legal platform, isolation by design
A private multi-tenant system for claims, foreclosure, and dunning — where one tenant reaching another’s data is the failure that matters most.
Tenant-isolation architecture by Theo; implementation by senior Cult of Coders engineers.
ResultTenant isolation enforced by the architecture itself, covering the full workflow set.
04About Theo
Founder, principal engineer, AI systems advisor
I co-founded Cult of Coders in 2015 and have spent the years since building software companies and the systems underneath them. Day1 is the part I do personally: strategy, architecture, and the technical calls that are hard to reverse.
Every engagement is led by me. I answer for the architecture, the critical decisions, and the quality of the result; larger builds ship with a small senior team from Cult of Coders, and you know who does the work before we start.
I have written software in public since 2012; the tools I created or maintain, BlueLibs and RedisOplog among them, are used well beyond my own clients.
- Writing software in public
- 2012
- Co-founded Cult of Coders
- 2015
- GitHub stars on open source
- 1,900+
- Public repositories
- 45
Based in Romania, working with teams across Europe and North America.
05Fit
A good fit, said out loud
The fastest way to know whether a conversation is worth your time.
Good fit
- A real decision or build that needs an owner.
- An ambitious idea — even if you’re not sure yet how to build it.
- A path to production — users, budget, a deadline that matters.
- Willingness to measure the result after it ships.
Poor fit
- A generic chatbot without a defined use case.
- A large, anonymous outsourcing team.
- AI for the press release, with no problem behind it.
- A speculative prototype with no owner and no budget.
06Contact
Discuss a real project.
Tell me what’s on the table. I reply personally, usually within one business day.