The Challenge
A consulting firm with 45 employees was managing over 200 active client engagements using a patchwork of spreadsheets, email threads, and a generic project management tool that didn't fit their workflow.
The pain points:
- No unified view – Partner-level visibility required manually compiling data from 4 different sources every Monday morning
- Client communication gaps – No client portal; status updates sent via email, often delayed or inconsistent
- Resource allocation guesswork – Consultants double-booked or underutilized because no one had real-time availability data
- Revenue leakage – Unbilled hours slipping through the cracks; estimated $12,000/month in missed billings
- Compliance risk – Audit trail for client deliverables stored across personal drives and email attachments
Traditional development quotes:
Three agencies quoted $80,000-$150,000 over 4-6 months for a custom platform. One suggested an off-the-shelf ERP at $3,000/month plus $40,000 implementation – but it would require the firm to change their proven workflow to fit the software.
The Solution
FastDX used vibe coding methodology – combining experienced human architects with AI coding tools – to build exactly what the firm needed at a fraction of traditional cost and timeline.
How vibe coding worked on this project:
- Human architect designed the system – A senior engineer spent 2 days with the partners understanding their workflow, data model, and integration requirements
- AI generated the foundation – Using Claude Code and GitHub Copilot, the architect generated the core application structure, database schema, and API layer in hours instead of weeks
- Human reviewed every decision – Architecture choices, security patterns, and business logic were validated by the engineer – AI accelerated execution, not decision-making
- Rapid iteration with real users – Working prototypes were shared with the team within days, feedback incorporated in hours
What we built:
- Engagement Dashboard – Real-time view of all 200+ client engagements with status, timeline, and assigned consultants
- Client Portal – Clients log in to see project progress, deliverables, and upcoming milestones
- Resource Planner – Visual calendar showing consultant availability, skills, and current assignments
- Time & Billing – Automatic time tracking integrated with engagement milestones, flagging unbilled work
- Document Hub – Centralized deliverable storage with version control and client access permissions
- Partner Analytics – Revenue pipeline, utilization rates, and profitability by engagement type
Technical approach:
- Stack: Next.js (App Router), Supabase (PostgreSQL + Auth + Storage), deployed on Vercel
- AI tools used: Claude Code for architecture and complex logic, GitHub Copilot for routine implementation
- Timeline: 2 weeks from kickoff to production deployment
- Team: 1 senior engineer with AI acceleration
- Code quality: Full TypeScript, automated testing, clean modular architecture
Week-by-week breakdown:
- Week 1: System design (2 days), core platform development – engagement management, user auth, client portal, resource planner
- Week 2: Time & billing module, document hub, partner analytics, integration testing, data migration, go-live
The Results
After 2 months on the new platform:
| Metric | Before | After | Impact | |---|---|---|---| | Revenue leakage (unbilled hours) | $12,000/month | $0 | $144,000/year recovered | | Development cost | $80,000-$150,000 (agency quotes) | $15,000 | 80% cost savings | | Partner reporting time | 4+ hours/week each | Automated | 16+ hours/week saved | | Client status inquiry emails | High volume | 70% reduction | Portal self-service | | Resource utilization | Unknown | +18% improvement | Eliminated double-bookings | | Deliverable audit trail | Scattered (email/drives) | Centralized with version history | Compliance-ready | | Payback period | – | 1.25 months | $15K cost vs $12K/month recovered | | First-year ROI | – | – | $144K recovered + $48K efficiency = $192K value |
Why AI-Assisted Development Worked Here
This project illustrates the sweet spot for vibe coding: a clearly defined business problem, an experienced architect who understands both the domain and the technology, and AI tools that multiply that expertise.
What AI did well:
- Generated boilerplate code (auth flows, CRUD operations, API routes) in minutes instead of days
- Produced consistent, well-structured TypeScript across the entire codebase
- Handled repetitive patterns (form validation, error handling, responsive layouts) without fatigue
- Generated comprehensive test suites covering edge cases a human might miss
What humans did better:
- Designed the data model to match actual business workflows (not generic templates)
- Made security decisions (RLS policies, access control, data isolation)
- Prioritized features based on business impact, not technical complexity
- Validated that the AI-generated code actually solved the business problem
Client Feedback
"We expected to spend six figures and wait half a year. Instead, we got exactly what we needed in two weeks for a fraction of the cost. The platform fits our workflow perfectly because a real architect designed it – the AI just made the build impossibly fast."
– Managing Partner
Key Takeaway
AI-assisted development is not about replacing developers – it's about giving experienced engineers superpowers. A senior architect who understands the business problem can now deliver in weeks what used to take months, at a fraction of the cost. The quality isn't compromised because humans still make every important decision; AI handles the execution at machine speed.
