sahana srivatsan

linkedin

cv

01 / overview

02 / priorities

03 / process

01 / overview

02 / priorities

03 / process

UX CASE STUDY — 02

comparative → custom reports: retiring legacy infrastructure without losing trust

comparative → custom reports: retiring legacy infrastructure without losing trust

ROLE

Lead designer

DURATION

February 2026- May 2026

DISCIPLINES

Feature audit

Data visualization

Legacy sunsetting

IA

69% decrease

in negative voice of customer feedback

$2.2M

MRR protected

$3M

infrastructure savings

Mailchimp ran two competing reporting tools for years longer than intended. They each pulled from different data sources, so customers could see two different numbers for the same campaign without an explanation why.


I led the migration: closing the feature gap, automatically moving ~4,700 legacy users to the modern tool, and retiring the old one entirely, without high value customers experiencing the change as a loss.

01 - problem

two similar seeming tools with mismatched capabilities

  • Two similar tools but with different capabilities and sources

    Comparative reports and custom reports pulled from different data sources, so customers regularly saw conflicting numbers for the same campaign between the two without a traceable reason for the mismatch.

  • The modern tool couldn't yet do everything the legacy one could

    Custom reports lacked breakdown by segment and tag which was the capability power users relied on comparative reports for, and one of the most-requested features in the product, with very high hvc interest.

  • There wasn't a clear way to see revenue metrics

    Comparative reports was entirely focused on engagement metrics (opens, clicks) with no way to connect campaign performance to conversions or business outcomes.

  • We stopped investing new features in the legacy tool

    Bot filtering, new conversion metrics, and new channels like whatsapp were only ever built for custom reports

FROM
FROM

Comparative reports builder with segmentation

TO
TO

Custom reports builder with comparative reports capabilities

FROM
FROM

Comparative reports builder with segmentation

TO
TO

Custom reports builder with comparative reports capabilities

FROM
FROM

Comparative reports builder with segmentation

TO
TO

Custom reports builder with comparative reports capabilities

02 — the approach

close the gap, then migrate without anyone noticing

Given the number of teams and customers this touched, I treated parity and migration as two separate, sequenced problems rather than one big-bang release:


01 ) Bring custom reports to parity first. Before migrating anyone, I scoped the exact feature gap against comparative reports - simple filters, breakdown by segment and tag, ecommerce conversion metrics, bot-filtered data, and access to new channels (automation, sms, whatsapp) and we made closing the gap a hard prerequisite for migration, not a fast-follow.


02 ) Design the migration to be invisible. rather than asking customers to manually rebuild their reports, I designed for automatic migration of saved comparative reports into custom reports


03 ) Sequence a multi-team rollout on a hard timeline. the migration touched legal, lifecycle marketing, pricing & lineup, and engineering


03 — process

notifying customers

first we alerted customers about the sunsetting of comparative reports 30 days before in the app through messaging and a lifecycle marketing email in case they didn't login within those 30 days

complex filtering logic

segmentation inside of custom reports

adding segmentation

Segmentation was already heavily used by our highest-paying customers in comparative reports, so it wasn't optional — shipping it as anything less intuitive than what they had risked churning the customers we could least afford to lose.

"i want to see the data in a table and be able to export it, export multiple metrics at once like on a dashboard, and set up custom reports with automated email."


— customer, beta survey respondent

feature parity

We next needed to ensure that we built gave customers the ability to slice their data by all of the metrics they were able to with the comparative reporting tool

02 — the approach

close the gap & migrate without anyone noticing

Given the number of teams and customers this touched, I treated parity and migration as two separate, sequenced problems rather than one big-bang release:


01 ) Bring custom reports to parity first: Before migrating anyone, I scoped the exact feature gap against comparative reports - simple filters, breakdown by segment and tag, ecommerce conversion metrics, bot-filtered data, and access to new channels (automation, sms, whatsapp) and we made closing the gap a hard prerequisite for migration, not a fast-follow.


02 ) Design the migration to be seamless: Rather than asking customers to manually rebuild their reports, I designed for automatic migration of saved comparative reports into custom reports


03 ) Sequence a multi-team rollout with a timeline: the migration touched legal, lifecycle marketing, pricing & lineup, and engineering

03 — process

Notifying customers

First we alerted customers about the sunsetting of comparative reports 30 days before in the app through messaging and a lifecycle marketing email in case they didn't login within those 30 days

Filters & expansion of metrics

We next needed to ensure that we built gave customers the ability to slice their data by all of the metrics they were able to with the comparative reporting tool

Adding segmentation

Segmentation was already heavily used by our highest-paying customers in comparative reports, so it wasn't optional — shipping it as anything less intuitive than what they had risked churning the customers we could least afford to lose.

segmentation inside of custom reports

"i want to see the data in a table and be able to export it, export multiple metrics at once like on a dashboard, and set up custom reports with automated email."


— customer, beta survey respondent

04 — validation

some of our wins

We needed to migrate comparative reports users to an at-parity custom reports with minimal disruption, and the $2.2m in MRR tied to those accounts needed to be protected since those users would be at risk of churning.


  • 4,700 users migrated automatically from comparative to custom reports, with no manual rebuild required on their end.


  • $2.2m in mrr protected through the migration, plus $3m in infrastructure cost savings from retiring the legacy comparative reports stack.


  • Comparative reporting voc dropped 69% post-launch (133 → 41 complaints, per unitq) — customers experienced the migration as an upgrade, not a loss.


  • Closed a long-standing competitive gap: segment/tag breakdown, ecommerce conversion metrics, and bot-filtered data now exist in mailchimp's reporting tool the way they already did in klaviyo and hubspot's.

next project: email report modernization

next project: email report

have a question about this project, or similar reporting problems on your plate?

have a question about this project, or similar reporting problems on your plate?

let's chat

let's chat

2026 sahana srivatsan

brooklyn, nyc

8:03:31 PM

brooklyn, nyc

8:03:31 PM