What to refactor this quarter,and why.
Top 5 risky features
Why it’s here: 63% of last-quarter commits were bug fixes. Two recent prod incidents originated here. Cross-cuts billing, email, calendar sync.
Ownership: Originally @ksenia (left Q2 2024); now distributed across 4 contributors with no clear lead.
Why it’s here: Quiet on the surface but absorbed 41% of the on-call paging volume. Most fixes are 1-line patches against the same retry loop.
Ownership: @maks owns 78% of recent commits; bus-factor risk if he rotates off.
Why it’s here: Three customer-reported regressions in 60 days. Code path is the oldest in the repo and predates the current rendering model.
Ownership: No clear owner — last meaningful refactor was 14 months ago.
Why it’s here: Quota errors creeping up. The adapter shares state with the iCal sync but has diverged — the same bug fixed twice in different files.
Ownership: @dima + @paul touch it monthly; neither considers it 'theirs'.
Why it’s here: Lower bug density than the others, but every bug here is a customer dispute. Risk profile is asymmetric.
Ownership: @anna is the de-facto owner; documented hand-off never happened.
Ownership gaps
Original author left 8 months ago. 3 contributors since, none with > 20% of commits. No single person can defend a design choice.
@maks owns 91% of meaningful changes. If he rotates, the team loses operational context that isn't in the code.
Touched by 11 different people in the last year, no concentration above 18%. Decisions get re-litigated every quarter.
Recommended refactor priorities
Highest-blast risk on the list. Pair the rewrite with a documented ownership hand-off. Estimated 3 engineer-weeks. Unblocks reliable shipping in 4 adjacent features.
Cheap, contained, paid back in on-call hours within one quarter. ~1 engineer-week. Assign before @maks rotates off.
Largest scope of the four. Worth a design doc this quarter so the rewrite isn’t blocked on shape decisions when capacity opens.
Symptom of the Booking engine, not a root cause. Re-evaluate after Booking lands; many issues should disappear with it.
Why these, not others
The 5 features above account for57% of recent bug-fix commits and4 of the 6 customer-reported incidents in the last 180 days, while representing only 8% of files. Effort against any of them is concentrated leverage.
We deliberately excluded several features with low health scores (e.g.Notifications · Email templates) because their blast radius is small and a rewrite would not change customer-visible behavior or on-call load this quarter.