Coherent product build
LifeOS Junior
A coherent, full-stack product build - useful as proof of a complete product shape.
Vue 3 · TypeScript · Express · PostgreSQL · Docker · CI
Serie3 - production software, fixed scope, fixed fee
The product a full engineering team would build. In 8-16 weeks. For a fixed fee.
Serie3 is one senior architect running a governed, AI-assisted delivery system. You get a serious product shipped to production - and every requirement, decision, and test written down, so your next team can own it from day one. It starts with a paid discovery sprint, not a leap of faith.
For funded founders who need a real product in production before - or instead of - hiring a team. Already have engineers who need senior direction? Fractional CTO is available too.
01 / What You Get
Not a deliverable. A capability - installed, then yours.
Early technical decisions compound. The traps are familiar: a demo that collapses the moment it has to become a real system, agency code your team can't extend, a freelancer whose knowledge leaves when they do, or a six-month, quarter-million-a-year search for a CTO. Serie3 replaces that with one fixed-scope build: architecture, senior implementation, predictable delivery, and the written record of every decision. What stays behind is the system and the documentation to run it - knowledge that lives in your repository, not in anyone's head, including mine.
01
Architecture that survives contact with reality
A system designed to be built, operated, and evolved - not a prototype you throw away the moment it succeeds.
02
Production implementation, not a proof of concept
The real application, platform, integrations, data model, and deployment surface - shipped, monitored, and handed over with a runbook.
03
Predictable AI delivery
The speed of AI, with every change reviewed against the architecture and every decision recorded - so velocity produces a clean codebase, not one no one can maintain.
04
Technical leverage for the founder
The clarity to raise, hire, and sell - with honest answers about what's solved and what isn't, written where you can use them.
02 / Engagement
Start small. Build to production. Hand over clean.
Most clients start with a paid discovery sprint and continue into a fixed-scope build. Fractional CTO is a separate engagement for teams that already have engineers.
Option 1 - Build Engagement
You need software delivered.
Serie3 delivers a defined outcome - architected, shipped to production, and handed over. Fixed scope, fixed fee, a clear end - not an open-ended retainer. Every build begins with a 2-3 week discovery sprint (USD 15-25k, credited in full against the build) that produces the spec, the architecture, and a fixed quote you can hold me to.
Building a comparable team the usual way means a senior architect and two or three engineers: roughly USD 600k-1M a year, and four to six months to hire. A build engagement compresses that into 8-16 weeks for a single fixed fee.
Three sizes
Focused Build
USD 100k-150k (+0.25-0.5%)
6-8 weeks
A narrow product with clear scope, one primary user journey, and limited integration risk.
Core Platform
USD 150k-225k (+0.5-1%)
10-12 weeks
A meaningful product surface: backend, frontend, integrations, data workflows, and production deployment.
Complex System
USD 225k-300k (+1-1.5%)
14-16 weeks
Platforms involving AI, real-time behavior, multi-role workflows, data infrastructure, regulated domains, or high architecture risk.
Builds run USD 100k-300k. Equity of 0.25-1.5% is optional upside alignment, never a substitute for the fee. Founding clients: equity can be waived in exchange for a public case study and a reference call.
Option 2 - Fractional CTO
You already have engineers.
You already have engineers. I help them become a high-performing engineering organization: setting technical direction, raising the standard, and making delivery predictable - and leaving it stronger than when I arrived.
The product is judgment, not code.
Typical responsibilities
- Architecture & technical direction
- Hiring & mentoring engineering leads
- Engineering standards & process
- Safe AI adoption in engineering
- Technical strategy
- Product roadmap
- Executive & board guidance
USD 8-24k / month · ongoing, 1-3 days/week
No software delivery included.
What you keep
Every build leaves behind more than working software: the documented decisions, runbooks, and standards your next team inherits - not a black box they have to reverse-engineer.
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Architecture decisions, written
Each non-trivial choice documented as a decision record. The founder can read it; the next engineer can extend from it.
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Production deployment + runbook
The system ships live, with a runbook covering deploy, rollback, monitoring, and the failure modes that actually matter.
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Weekly founder-readable updates
Plain-English progress every week: what shipped, what's next, what's at risk, what needs your decision.
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An afternoon's handoff
A written handover an incoming CTO or first engineering hire can absorb in an afternoon and pick up from cold.
Starting structures, not menu prices. The discovery sprint sets the final scope and a fixed price in a written agreement. Serie3 takes no equity-only work.
03 / The System
AI speed, predictable delivery.
The advantage isn't using AI - everyone uses AI. The advantage is Spec-Driven Engineering: every requirement is written as a spec, every architectural decision is documented, and every change is reviewed and validated against it. The result is predictable delivery - the codebase stays clean and understandable even when it's built at AI speed. It's how one senior architect produces the output of a team without losing control of the result.
- 01
Discovery Sprint
2-3 weeks, paid, credited against the build. Business goal, user journeys, system boundaries, and real technical risks - ending in a written spec, an architecture outline, and a fixed quote. If we stop here, you keep all of it.
- 02
Architecture
Establish the core model, integration boundaries, deployment approach, data flows, and the non-negotiable quality constraints.
- 03
Governed Build
AI-assisted development under review, with clear ownership, tests, documentation, and decision records at every step.
- 04
Production Readiness
Real users: deployment, observability, a security baseline, and founder-facing technical clarity.
- 05
Handoff
A coherent codebase, architecture notes, operating instructions, and a clear path to hire or continue.
04 / Fit
Built for problems that can't be faked with a template.
Good fit
- You need a serious product in production - before you hire a team, or faster than your team can deliver it.
- You're funded, revenue-backed, or capitalized enough to invest seriously - USD 15-25k to start with discovery, USD 100k+ for the build.
- The technical work has real weight: architecture, integration, data depth, AI, real-time, or regulated domains.
- You want senior judgment, not just more hands.
- You want to own what's built - code, decisions, and documentation - not rent it.
Not a fit
- You need a landing page or a simple CRUD app.
- You want the cheapest possible MVP.
- You expect equity to replace cash.
- You want a large agency team, or code without architectural judgment.
- You're looking for a permanent co-founder or a full-time CTO seat.
05 / Proof
Two decades of systems that had to work.
Serie3 was founded by Boban Karisik after two decades designing and leading enterprise software systems. The methodology behind it evolved from solving the same delivery, architecture, and quality problems across real-world platforms, not from theory - the hard part was never writing the software, it was making quality predictable.
The internal lab is proof the method is current: complete, product-shaped systems built with the exact AI-assisted delivery method your engagement would use - same architecture discipline, same documentation, same production hygiene.
01
Government digital services
Identity, integration, auditability, and operational resilience in public-sector systems.
02
Fintech and regulated platforms
Transaction systems, security-sensitive integrations, and availability under real constraints.
03
Operational intelligence
Data platforms, digital twins, simulation, real-time response, and AI-assisted decision surfaces.
04
AI delivery that stays maintainable
A proven way to build with AI agents at speed while keeping the architecture clean, the decisions documented, and the code something a team can still maintain.
Internal Lab
Built with the exact method your build would use.
Enterprise platform credibility
Zora MDM
Enterprise master data management platform with stewardship workflows, auditability, and operational documentation.
PostgreSQL · PostGraphile · Vue 3 · Authentik · NATS
Hard-system credibility
Sentinel
Real-time OSINT and geospatial intelligence system: ingest, normalization, anomaly detection, situation lifecycle, and self-hosted deployment.
Real-time · Geospatial · OSINT · Self-hosted
Internal lab projects, not client case studies - complete, product-shaped systems that show the method, the range, and the engineering standard you would get.
Evidence
What a build actually produces
Most vendors show logos. This is what you actually get at the end of a build - and you can download a real one before we ever talk.
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01
Specification
Every feature written as a clear, testable spec before code - so what's being built is agreed up front, not assumed.
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02
Architecture Decisions
A dated record of each significant technical choice and the reasoning behind it - the context your next engineer would otherwise have to reverse-engineer.
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03
Validation Scenarios
The concrete cases the system is checked against - expected behavior, edge cases, and failure modes, written down and run.
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04
Evidence Report
Proof that what was specified actually works: results tied back to each requirement, so 'done' means demonstrated, not claimed.
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05
System Documentation
How the system is built and operated - architecture, data model, integrations, and the runbook to deploy, monitor, and recover it.
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06
Handover Package
Everything an incoming engineer or CTO needs to take ownership in an afternoon - code, decisions, docs, and operating instructions in one place.
24 of these documents from a real build, organized exactly as they're handed over. Your details just let me follow up.
Or read the executive summary (PDF)06 / Contact
Start with a discovery sprint.
Send a short note: where you are, what needs to exist in production, your rough budget and timeline, and what makes it technically hard. You'll get a real answer within 48 hours - and, if it's a fit, a discovery sprint proposal.
Not a fit for staff augmentation, generic outsourcing, equity-only projects, a permanent full-time CTO seat, or commodity websites.
FAQ
Questions
Is Serie3 an agency?
No. Serie3 is one senior architect with a governed, AI-assisted delivery system - architecture, implementation, and founder-facing technical judgment. You don't buy headcount; you buy a working product plus the specs, decisions, and runbooks a good team would leave behind, without hiring or managing one.
Do you work for equity only?
No. Every engagement carries a cash fee that stands on its own. Equity is upside alignment, never a substitute for budget.
Do you work as a fractional CTO?
Yes - it's one of two separate engagements. As fractional CTO the work is judgment, not delivery: technical direction, hiring and mentoring, engineering standards, and strategy - leaving your team stronger than it started. It's the senior technical seat for the stretch before you hire a permanent one, not a forever executive role. If you need software actually built, that's the separate build engagement - and the two can be combined.
What stage is best?
Seed to Series A. For a build: when you need a serious product in production before a full team exists. For a fractional CTO: when you have engineers but no senior technical leader.
What happens when an engagement ends?
After a build: a clean handover to your team, a focused support phase, another defined phase, or help making your first technical hires. After a fractional-CTO engagement: your team keeps the standards and direction, and can roll into a build if delivery becomes the next need.
What if you become unavailable? Isn’t one architect a single point of failure?
That risk is exactly what the method is built to remove. Every requirement is a spec, every decision is a dated record, every behaviour is a validation scenario, and the runbook covers deploy, rollback, and recovery - all in your repository from week one, not at the end. Any competent engineer can pick the system up from that record in an afternoon. The lab projects on this page (LifeOS Junior, Zora MDM, Sentinel) are internal work, built the same way - evidence of method, not client case studies.