Brainshelf: Follow the Product¶
Post-seed, ~20 employees, ~22,000 MAU. Building Resurface — contextual morning email digest.
Prompt style: Casual — rough, fast, enough context to work. Bullet points and shorthand.
Phase: Foundation¶
Persona (Marketing Brief)¶
Brainshelf marketing persona for newsletter-creator acquisition and content-curation positioning
Prompt
/persona marketing brief
marketing persona for newsletter creator acquisition channel.
context: brainshelf users who share 3+ items/week have 3.4x retention
and 2.1 referral signups/quarter [fictional]. newsletter creators are
a natural fit because they already curate. want a persona for
acquisition messaging and potential "Curator" tier positioning.
competitors in this space: Readwise Reader, Raindrop, Pocket.
keep it brief but actionable for growth experiments.
Full output: Persona (Marketing Brief)
Persona Dossier: Amara Osei, The Creator Who Curates Before She Writes (Marketing, Brief)¶
Persona (Marketing Detailed)¶
Brainshelf Resurface marketing persona for freemium-to-paid conversion strategy and subscription messaging
Prompt
/persona marketing detailed
need a marketing persona for the Resurface premium conversion funnel.
context: brainshelf is prepping the freemium-to-paid strategy for
Resurface. free users can see 3 resurfaced items per week but premium
unlocks unlimited plus custom filters. want a persona to drive paywall
copy, trial-to-paid nurture, and acquisition messaging.
key concern: user research shows 4/7 interviewees said they've abandoned
paid productivity tools before. subscription fatigue is the real
competitor, not Readwise.
28% of free users hit the weekly limit at least once [fictional]
but only 4% convert within 30 days [fictional]
include trigger events, objections, messaging architecture, and
evidence trail.
Full output: Persona (Marketing Detailed)
Persona Dossier: Jess Okafor, The Reluctant Subscriber (Marketing)¶
Persona (Product Brief)¶
Brainshelf Resurface activation persona for early-retention product decisions
Prompt
/persona product brief
Need a concise story-first product persona for Brainshelf Resurface activation work.
Context:
- Product: Brainshelf (consumer PKM app)
- Feature: Resurface morning digest and revisit flow
- Problem: users open first digest, but many do not form repeat revisit behavior
- Downstream artifacts: hypothesis revision, user stories, edge-cases
Please include:
- clear decision posture and tradeoff lens
- includes/excludes boundaries
- scenario tailoring for hypothesis, user stories, edge-cases
- assumptions/confidence/evidence trail
Full output: Persona (Product Brief)
Persona Dossier: Maya Torres, The Habit Builder Under Time Pressure (Product, Brief)¶
Persona (Product Detailed)¶
Brainshelf Resurface product persona for power-curator workflows and advanced resurfacing customization
Prompt
/persona product detailed
detailed persona for Brainshelf Resurface power curator segment.
context: we're scoping resurface v1.1 and the power curators are a
different animal from casual users. they save 80+ items/month [fictional],
use tags and folders, and their mental model of their library is
structured. the current relevance algorithm doesn't respect their
curation choices.
7% of MAU, 42% of shares [fictional]. they're the word-of-mouth engine.
need this for PRD scoping, user stories, and edge cases around topic
filters, curation-aware relevance, and search within resurface.
include full decision model, workflow friction, and evidence trail.
Full output: Persona (Product Detailed)
Persona Dossier: Tomás Reyes, The Architect of His Own Library (Product)¶
Phase: Discover¶
Competitive Analysis¶
Brainshelf consumer PKM app — competitive landscape for content resurfacing features
Prompt
/competitive-analysis
pkm and read-later market, focusing on resurfacing and re-engagement
features. brainshelf is planning a resurface feature (morning email digest
with 3-5 saved items) and need to understand the competitive landscape.
context: brainshelf is a consumer pkm/save-for-later tool, ~85k registered
users, ~22k MAU [fictional]. core problem is users save tons of stuff but
never come back to read it — 47 items saved/month, <9% revisited within
30 days [fictional].
4 competitors to analyze: readwise, raindrop.io, pocket (mozilla),
instapaper. focus on resurfacing features, email digests, pricing,
and where the white space is for us.
Full output: Competitive Analysis
Competitive Analysis: PKM / Read-Later Content Resurfacing¶
Interview Synthesis¶
Brainshelf consumer PKM app — user interviews on saved content re-engagement
Prompt
/interview-synthesis
ran 7 user interviews over the past 2 weeks about why people save stuff
to brainshelf but never go back to read it. need to synthesize the findings.
interviews were video calls, 30-45 min each. mix of heavy savers,
occasional users, and one churned user.
main findings:
- 5/7 described their library negatively ("guilt pile", "overwhelming", etc)
- nobody has a natural trigger to go back and read saved stuff
- there's a weird split between "saving to read later" and "saving to have"
that people don't realize until you ask them
some great quotes. need this formatted for the team before we start
building the hypothesis doc for resurface.
Full output: Interview Synthesis
Interview Synthesis: Why Users Save but Don't Return¶
Stakeholder Summary¶
Brainshelf consumer PKM app — internal stakeholder map for the Resurface feature
Prompt
/stakeholder-summary
need to map the internal stakeholders for the resurface feature before
we kick off the build. brainshelf is a ~20 person startup so this is
small-team politics, not enterprise governance.
key people:
- marco (ceo/cofounder) — big advocate, sees this as the retention bet
- alex (eng lead) — supportive but worried about A/B test infrastructure
- jordan (growth) — wants resurface as the retention lever
- dan (designer) — concerned about the digest feeling spammy
- chloe (data) — needs instrumentation for the experiment
want a proper stakeholder map with communication plan.
Full output: Stakeholder Summary
Stakeholder Summary: Resurface Feature¶
Phase: Define¶
Problem Statement¶
Brainshelf consumer PKM app — saved content re-engagement problem statement
Prompt
/problem-statement
the guilt pile problem. users save a ton of stuff to brainshelf but
never come back to read it. interview data says 5/7 users described
their library negatively. behavioral data says <9% revisit rate within
30 days [fictional]. 7-day return rate is 18% [fictional], OKR target
is 25% [fictional] by end of Q2.
need a clean problem statement to align the team before we start
building the resurface hypothesis.
Full output: Problem Statement
Problem Statement: Saved Content Re-Engagement Gap¶
Hypothesis¶
Brainshelf consumer PKM app — Resurface morning email digest hypothesis
Prompt
/hypothesis
trying to figure out if a morning digest email will actually get people to re-read
their saved stuff. context: brainshelf pkm app, 22k MAU [fictional]. users save
~47 items/month but only go back to read ~9% within 30 days [fictional]. classic
guilt pile problem from interviews.
want to run an A/B test on a morning email that surfaces 3-5 items from their
library based on what they've been reading lately. need a hypothesis doc to
align the team before we commit to building it.
primary metric: resurface item click rate. secondary: actual read completion.
guardrail: don't tank unsubscribe rate.
Full output: Hypothesis
Hypothesis: Morning Resurface Email Increases Re-Read Rate¶
Opportunity Tree¶
Brainshelf consumer PKM app — opportunity tree for saved content re-engagement
Prompt
/opportunity-tree
outcome: increase 7-day return rate from 18% to 25% [fictional]
by end of Q2 2026.
three opportunities from interviews + data:
1. re-engagement trigger gap — users have no external prompt to return
2. content relevance decay — old saves lose timeliness, making the
library feel stale
3. library overwhelm — 400-item undifferentiated list creates avoidance
solutions I'm considering:
- opp 1: morning email digest (resurface), in-app notification card
- opp 2: freshness scoring, auto-archive stale items
- opp 3: intent tagging at save time, smart collections
want to prioritize opp 1 / email digest based on competitive analysis
(readwise is the only proof point for email resurfacing).
Full output: Opportunity Tree
Opportunity Solution Tree: Increase 7-Day Return Rate¶
JTBD Canvas¶
Brainshelf consumer PKM app — JTBD canvas for saved content re-engagement
Prompt
/jtbd-canvas
the core job for the resurface feature. users save stuff to brainshelf
with the intent to read it later, but the act of saving satisfies the
intent — they never actually come back. so the real job isn't "save to
read later" (that job is already done by the save action), the real job
is "rediscover the things I saved that are still worth my time."
based on 7 user interviews (jan 2026). guilt pile is the emotional
dimension. social dimension: people want to seem well-read but their
library proves they're not.
competing solutions: readwise (expensive), browser bookmarks (no resurface),
doing nothing (guilt pile grows), raindrop.io (organize but no resurface).
Full output: JTBD Canvas
Jobs to be Done Canvas: Rediscover Saved Content Worth My Time¶
Phase: Develop¶
Solution Brief¶
Brainshelf consumer PKM app — Resurface feature solution brief for team alignment
Prompt
/solution-brief
resurface one-pager for the team. need to get everyone on the same
page before sprint 8 starts. marco wants to see it too.
the solution: daily morning email digest that surfaces 3-5 saved items
matched to what the user has been reading recently. opt-in required.
7:30 AM local time. topic matching algorithm picks the items.
key features: email digest, topic matching, opt-in flow, one-click
read, cadence setting (daily default, can switch to 3x/week).
primary metric: 7-day return rate, 18% → 25% [fictional].
secondary: email CTR. guardrail: unsub rate ≤2%/week.
explicitly NOT doing: in-app resurfacing (deferred), push notifications
(too aggressive for first version), smart collections (too big),
annotation-based resurfacing (that's readwise's approach, we're
doing topic matching instead).
Full output: Solution Brief
Solution Brief: Resurface — Morning Email Digest¶
Spike Summary¶
Brainshelf consumer PKM app — topic-matching algorithm spike for the Resurface digest
Prompt
/spike-summary
topic matching spike for resurface. alex spent 3 days on it last
week. question: can we build something that picks saved items relevant
to what the user has been reading recently, accurate enough to not
annoy people?
three approaches tested:
1. tag-based — use OG tags, domain, URL patterns. simplest, no ML.
2. tfidf — extract article text, vectorize, cosine similarity. no
external api. medium complexity.
3. openai embeddings — text-embedding-3-small. highest accuracy but
adds external dependency and per-call cost.
benchmark: 3 real user libraries (anonymized), 50 items each,
manually rated as "relevant" or "not relevant" to recent reading.
results: tags = ~55% [fictional], tfidf = ~72% [fictional],
embeddings = ~84% [fictional].
recommendation: go with tfidf for mvp. meets the 70% bar we set,
no external dependency. plan to migrate to embeddings later if the
feature sticks.
Full output: Spike Summary
Spike Summary: Topic-Matching Algorithm for Resurface Digest¶
Architecture Decision Record¶
Brainshelf consumer PKM app — email sending infrastructure decision for the Resurface digest
Prompt
/adr
email sending infra for resurface. we don't have any email sending
today — everything is in-app or firebase push. need to pick a provider
for the daily digest.
options we looked at:
- sendgrid (twilio): mature, everyone uses it, but their free tier
shrank and the dashboard is confusing
- postmark: great deliverability reputation, simple api, but
transactional only — no batch/digest support without workarounds
- resend: new, developer-first, react email templates, free tier
covers our a/b test volume
alex ran a quick eval last week. we're leaning resend. need the ADR
written up before sprint 8 starts.
Full output: Architecture Decision Record
ADR-007: Use Resend as the Email Sending Provider for the Resurface Digest¶
Design Rationale¶
Brainshelf consumer PKM app — digest email layout design decision for the Resurface feature
Prompt
/design-rationale
digest email layout for resurface. dan showed three options:
option A: rich cards — article thumbnail, title, excerpt, topic tag
for each item. looks great in figma but heavy on images and might
trigger promotions tab.
option B: structured text — article title (linked), source domain,
topic tag, estimated read time. no images. clean, editorial feel.
fast to scan.
option C: minimal plain text — just titles and links, no styling.
maximum deliverability but looks like a system notification, not a
product experience.
we did a quick preference test with 12 users. 9 preferred option B.
reasons: "fast," "doesn't look like spam," "I'd actually read this."
going with B. need the rationale written up.
Full output: Design Rationale
Design Rationale: Resurface Digest Email Layout¶
Phase: Deliver¶
PRD¶
Brainshelf consumer PKM app — Resurface feature PRD for Sprint 8 build
Prompt
/prd
resurface prd for sprint 8. pulling everything together: solution brief,
adr (resend), design rationale (text layout), spike (tfidf).
building the daily email digest that surfaces 3-5 saved items matched
to recent reading. opt-in required. 7:30 AM local time. tfidf for
topic matching. resend for email. text-only layout.
target users: active savers (10+ items, active in last 30 days) —
about 9,800 users [fictional].
metrics: 7-day return rate 18%→25% [fictional], email CTR ≥15% [fictional],
unsub ≤2%/week [fictional].
scope: digest email, topic matching, opt-in flow, cadence setting,
one-click read, analytics events. NOT doing: in-app resurfacing,
push notifications, smart collections.
timeline: sprint 8 build (feb 3-16), setup week (mar 2-8),
a/b test (mar 9 - apr 5), decision (apr 11).
Full output: PRD
PRD: Resurface — Morning Email Digest¶
User Stories¶
Brainshelf consumer PKM app — Resurface user stories for Sprint 8
Prompt
/user-stories
resurface stories for sprint 8. need the full set with acceptance
criteria.
stories:
1. receive daily digest (P0) — the core email delivery
2. opt in to digest (P0) — home screen card + settings toggle
3. click item to read (P0) — one-click from email to article
4. change cadence (P1) — daily vs 3x/week
5. unsubscribe from digest (P0) — one-click from email footer
keep them tight. alex and jess need to estimate on monday.
Full output: User Stories
User Story: Receive Daily Resurface Digest¶
Edge Cases¶
Brainshelf consumer PKM app — Resurface digest edge cases and error states
Prompt
/edge-cases
resurface edge cases for sprint 8. need to cover:
- what happens when the user's library is too small
- what happens when all items have been resurfaced recently
- timezone weirdness (DST, user changes timezone, half-hour offsets)
- text extraction failures
- resend api outages
- user clicks a link to a dead URL
- email bounces
- concurrent opt-in/unsubscribe race conditions
alex wants this documented so QA can build the test plan from it.
Full output: Edge Cases
Edge Cases: Resurface Digest¶
Launch Checklist¶
Brainshelf consumer PKM app — Resurface feature launch checklist for Sprint 8 ship
Prompt
/launch-checklist
resurface launch checklist. shipping at end of sprint 8 (feb 14-16).
this is our first email feature so dns, deliverability, and compliance
are all new for us. need the full checklist.
key stakeholders: priya (pm/launch owner), alex (eng), jess (eng),
dan (design), sam (frontend), chloe (data), jordan (growth),
marco (ceo, go/no-go).
go/no-go meeting: feb 12. launch window: feb 14-16 behind feature flag.
opt-in enrollment starts mar 2. a/b test starts mar 9.
Full output: Launch Checklist
Launch Checklist: Resurface — Morning Email Digest¶
Release Notes¶
Brainshelf consumer PKM app — Resurface feature release notes for users
Prompt
/release-notes
resurface release notes. feature shipped feb 16 behind flag. opt-in
enrollment starts mar 2. writing for the in-app changelog and blog.
tone: friendly, plain language. not techy. our users are knowledge
workers who save articles — talk to them about reading, not about
algorithms.
highlights: daily email digest with your most relevant saved content,
delivered every morning. opt-in from home screen. one-click to read.
change frequency or unsubscribe anytime.
also: fixed the timezone bug from sprint 8 that sent early-morning
digests to UK/EU users. and improved text extraction for paywalled
articles (better fallback to article metadata).
Phase: Measure¶
Experiment Design¶
Brainshelf consumer PKM app — Resurface A/B test experiment design
Prompt
/experiment-design
resurface a/b test. feature is shipped behind a flag. need the full
experiment design for chloe to set up in amplitude.
hypothesis: daily digest → higher 7-day return rate.
design: intent-to-treat. treatment gets the opt-in prompt + digest.
control gets nothing (current experience). measure 7-day return rate
for both groups.
secondary metric: email CTR (treatment only — control doesn't get
email). guardrail: unsub rate ≤2%/week.
sample: 400 per variant from the 9,800 eligible users [fictional].
duration: 4 weeks (mar 9 - apr 5). 50/50 split on enrollment cohort.
want to have the design doc locked before the setup week (mar 2-8).
Full output: Experiment Design
Experiment Design: Resurface Daily Digest A/B Test¶
Instrumentation Spec¶
Brainshelf consumer PKM app — Resurface feature analytics instrumentation spec
Prompt
/instrumentation-spec
resurface analytics events for amplitude. need the full spec before
sprint 8 starts so alex and jess can instrument during the build.
events:
1. resurface_opt_in — user enables the digest
2. resurface_digest_sent — server sends a digest email
3. resurface_digest_opened — user opens the email (caveat: apple MPP)
4. resurface_item_clicked — user clicks an item in the digest
5. resurface_unsubscribe — user unsubscribes
6. resurface_cadence_changed — user changes frequency
7. resurface_digest_skipped — server skips sending (no qualifying items,
exclusion window exhausted, etc.)
also need user properties: digest_enabled, digest_cadence, digest_timezone.
keep it tight. chloe wants to review before sprint planning on monday.
Full output: Instrumentation Spec
Instrumentation Spec: Resurface Digest¶
Dashboard Requirements¶
Brainshelf consumer PKM app — Resurface experiment dashboard requirements for Amplitude
Prompt
/dashboard-requirements
resurface experiment dashboard for amplitude. need it ready before
the a/b test starts (mar 9).
two audiences:
1. product team (priya, chloe, alex, jordan) — daily monitoring
during the 4-week test
2. marco (ceo) — weekly exec check-in, needs a single-screen summary
questions the dashboard should answer:
- is the treatment group returning more than control?
- are users clicking items in the digest?
- is the unsubscribe rate within the guardrail?
- what's the opt-in funnel conversion rate?
- are there segment differences (library size, cadence)?
charts i want:
1. 7-day return rate trend (treatment vs control, weekly)
2. email CTR trend (daily)
3. opt-in funnel (card viewed → opted in)
4. unsubscribe rate trend (weekly, with guardrail line)
5. segment breakdown table (library size, cadence)
filters: date range, experiment variant, library size segment.
Full output: Dashboard Requirements
Dashboard Requirements: Resurface Experiment Dashboard¶
Experiment Results¶
Brainshelf consumer PKM app — Resurface A/B test results and ship decision
Prompt
/experiment-results
resurface a/b test results. test ran mar 9 - apr 5 (4 weeks).
800 users, 50/50 split [fictional].
headline: treatment won.
primary metric (7-day return rate):
- control: 18.1% [fictional]
- treatment: 23.4% [fictional]
- delta: +5.3pp, p = 0.008 [fictional]
secondary (email CTR, treatment only): 17.2% [fictional]
opt-in rate: 41% of treatment group (164/400) [fictional]
guardrails all passed:
- unsub: 1.3%/week [fictional] (under 2% threshold)
- app uninstall: no difference
- save rate: no difference
segments:
- heavy savers (100+ items): return rate lift = +7.1pp [fictional]
- light savers (10-50 items): return rate lift = +3.8pp [fictional]
- daily cadence users: CTR 18.6% [fictional]
- 3x/week users: CTR 14.1% [fictional]
surprising: opt-in rate was 41% [fictional], way above the 10% target.
also surprising: week 4 return rate was HIGHER than week 1 (not
novelty decay — habit formation).
recommendation: ship to all eligible users.
Full output: Experiment Results
Experiment Results: Resurface Daily Digest A/B Test¶
Phase: Iterate¶
Retrospective¶
Brainshelf consumer PKM app — Sprint 8 retrospective after Resurface launch
Prompt
/retrospective
sprint 8 retro — resurface launch sprint. need to write this up.
what happened: we shipped resurface on time! first big feature in 6 months.
but we also had a timezone bug that sent the morning digest at 5am to UK/Europe
users (~340 people [fictional]). caught it 6 hours after launch, patched within 2
hours of catching it, but some users were not happy.
format: start/stop/continue. small team (7 people in the room).
2 wins, the timezone thing, and a few process issues that came up.
previous retro action items were: (1) set up staging environment email testing —
DONE, (2) add integration test for notification delivery — NOT DONE (this
contributed to the bug), (3) weekly eng/pm sync — IN PROGRESS.
Full output: Retrospective
Retrospective: Sprint 8 — Resurface Launch¶
Lessons Log¶
Brainshelf consumer PKM app — timezone handling lesson from the Resurface Sprint 8 launch
Prompt
/lessons-log
lesson from: timezone bug at resurface launch
what happened: ~340 UK/EU users got their digest at 7:30 UTC instead
of 7:30 local because the backend didn't recognize "Europe/Kyiv" and
silently fell back to UTC.
detected: feb 18, 2026 — alex noticed the send log timestamps were
wrong for EU users.
fixed: feb 18, same day — updated IANA database, added explicit
fallback logging, patched within 2 hours.
lesson type: failure pattern / technical
the real lesson isn't the specific bug — it's that we had ZERO
integration tests for timezone-dependent behavior. the unit tests
mocked the timezone, so they never caught the gap between the device
timezone string and the server's IANA database.
Full output: Lessons Log
Mocked Timezones Hide Real-World Failures: Always Integration-Test Time-Dependent Features Against the Live IANA Database¶
Refinement Notes¶
Brainshelf consumer PKM app — Sprint 9 refinement for Resurface v2 improvements
Prompt
/refinement-notes
sprint 9 refinement for resurface v2. session was april 15, 2026.
45 minutes. priya facilitated.
stories discussed:
1. RSF-010: embedding migration (tfidf → openai text-embedding-3-small)
— BLOCKED, waiting on openai api key + budget approval from marco
2. RSF-011: in-app resurfacing card on home screen — Ready, 5 pts [fictional]
3. RSF-012: cadence experiment (daily vs 3x/week, larger sample) —
Ready, 3 pts [fictional]
4. RSF-013: small-library handling (users with <20 items, shorter
exclusion window) — Needs Work, alex wants to see the data first
questions raised: should the in-app card show different items than
the email digest or the same items? what's the minimum library size
where tfidf actually produces useful results?
decision: in-app card shows different items (complementary, not
duplicate).
Full output: Refinement Notes
Refinement Notes: April 15, 2026¶
Pivot Decision¶
Brainshelf consumer PKM app — post-experiment persevere decision for Resurface
Prompt
/pivot-decision
post-experiment pivot decision for resurface. a/b test showed +5.3pp
lift in 7-day return rate, p=0.008 [fictional]. all guardrails passed.
recommending: persevere — ship to all eligible users, invest in v2.
alternatives considered:
1. persevere: ship email digest, iterate on relevance and cadence
2. pivot to push notifications: replace email with mobile push as the
trigger mechanism
3. pivot to in-app resurfacing: replace email with in-app notification
card (deferred from the original opportunity tree as solution 1B)
need the formal decision doc for marco. decision date: april 11, 2026.
Full output: Pivot Decision
Pivot Decision: Resurface — Post-Experiment Evaluation¶
28 artifacts generated across the full PM lifecycle.
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