Legacy SaaS dossier · workday
Workday
An employee table, payroll exports, and PTO requests, wrapped in a six-figure implementation and a UI even HR admins refuse to defend.
01 · Data
Data the SaaS sits on
Internal Build Score
0.57
Feasibility of a useful internal substitute for the actually-used 20% of this SaaS, built with Claude and your own data layer.
IBS = 0.25·U + 0.25·C + 0.20·D + 0.15·I + 0.15·Mthis record · 57%- U
User adoption gap
weight 0.250.78How much licensed surface area sits idle.
- C
Core simplicity
weight 0.250.65How small the actually-used 20% is when re-implemented honestly.
- D
Data portability
weight 0.200.30How clean the exit is, exports, formats, audit lock.
- I
Integration burden (inverse)
weight 0.150.55How few external systems must keep working through the SaaS.
- M
Moat erosion
weight 0.150.50How much the original differentiator has been commoditised by LLMs + cheap infra.
Editorial heuristic. Not investment advice, not a procurement recommendation.
03 · Feature usage
Commonly used vs. rarely touched
Commonly used
05
- Employee directory with managers + cost centres
- PTO request + approval workflow
- Payroll provider integration / export
- Performance review cycles
- Headcount + org chart reporting
Rarely touched
08
- Business process framework, every form is its own BPMN graph
- Workday Studio + integrations (XSLT + EIBs)
- Adaptive Planning bolt-on sold as a separate product
- Calculated fields language nobody outside the partner pool reads
- Tenant-locked test environments refreshed on Workday's schedule
- 'Drive' / 'Help' / 'Journeys' modules layered over time
- Mandatory R1/R2 yearly upgrade windows
- $400/hr Workday-certified consultant gating every change
Internal build
Build it yourself
01 · Stack & flow
Internal build map
Data in
Agent layer
Logic
Outputs
- Build time
- 10 weeks
- Run cost
- $4/seat·mo
- vs. SaaS
- $750K all-in
Build outline
- Source-of-truth people schema in Postgres
- Slack bot for PTO request + manager approval
- Payroll provider SFTP export job
- Quarterly review form + Claude summariser
- Read replicas + audit log for SOC 2 evidence
02 · Claude prompt
First, map what you actually use (optional)
03 · Result
Strengths: 4 · Growth areas: 2 · Promotion read: ready · hr_flags: none