Legacy SaaS dossier · mailchimp
Mailchimp
A contact list, a template editor and a send queue, priced per contact so the bill grows with a list you already own.
01 · Data
Data the SaaS sits on
Internal Build Score
0.81
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 · 81%- U
User adoption gap
weight 0.250.80How much licensed surface area sits idle.
- C
Core simplicity
weight 0.250.85How small the actually-used 20% is when re-implemented honestly.
- D
Data portability
weight 0.200.80How clean the exit is, exports, formats, audit lock.
- I
Integration burden (inverse)
weight 0.150.70How few external systems must keep working through the SaaS.
- M
Moat erosion
weight 0.150.85How 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
- Subscriber list with segments
- Campaign composer + templates
- Scheduled and triggered sends
- Open / click tracking
- Signup forms and double opt-in
Rarely touched
06
- Per-contact pricing that climbs as your list grows
- Customer Journey builder most teams configure once
- AI subject-line and content add-ons
- Landing pages and a half-built website builder
- Postcards, a CRM and an appointments tool
- Predictive demographics and comparative reports
Internal build
Build it yourself
01 · Stack & flow
Internal build map
Data in
Agent layer
Logic
Outputs
- Build time
- 4 weeks
- Run cost
- $2/seat·mo
- vs. SaaS
- $30K / yr
Build outline
- Contacts + consent schema in Postgres
- Segments as saved SQL filters
- React Email templates, sent via Resend
- Open / click tracking pixel + redirect
- Claude drafts campaign copy per segment
02 · Build it
Paste into Cursor or Claude Code in an empty repo. It scaffolds the working core, with the AI step embedded.
03 · Result
3 subjects, top: 'Your workspace is still here' · 1 body · 0 review flags