2026-09-30 · 6 min read

How a Non-Engineer Built Tend

I forgot my best friend's birthday.

Not an acquaintance. My best friend from college. Google Calendar was supposed to remind me, and through some sync failure I never untangled, it didn't. The day came and went. I noticed days later, with the particular embarrassment of having outsourced remembering to a machine that quietly dropped the one thing I'd trusted it to hold.

That is the whole problem in one moment. Staying close to the people who matter becomes work, not out of indifference, but because knowing someone matters and remembering them at the right time are different skills, and only one of them scales.

Every tool that promises to fix this is a CRM wearing a friendly hat, and a CRM solves the problem by making you do the data entry. Nobody wants to run a sales pipeline on their friendships. So I built the opposite.

The problem: closeness becomes admin

The people you'd never put in a pipeline are the hardest to keep up with, because no system pushes you. Work relationships have CRMs, calendars, quarterly reviews. Your closest people have only your attention, and attention is the first thing that gets eaten.

So it slips. Her opening was Friday and you meant to text. He mentioned the job change and you meant to follow up. It's been three months, and you didn't decide that; it accrued. The standard answer is discipline: log your friends, tag them, set reminders, maintain the spreadsheet. It works for about two weeks. Data entry is a tax, and we don't pay taxes on the people we love. We feel guilty instead.

Tend is built around one reframe: the remembering is the product, and it should not be your job.

What I built

Tend runs a four-beat loop, and only the first beat is yours.

1. Capture. You leave one line, typed or spoken: "Saw Maya, her show opens Friday, she seemed lit up about it." Messy is fine. Messy is expected.
2. It remembers. That sentence becomes structured memory, a person, a few facts, a date, and the person's short "what matters" summary quietly rewrites itself. You never open a form.
3. Tend. The home screen shows three to five people, ranked by who matters, how long it's been, and what's still open, each with a one-line reason. Not a red badge saying overdue. A sentence that sounds like a friend reminding you.
4. Ask. In plain language: "Who should I check in with about a new job?" It reasons over your own notes and tells you.

To get started, it can read your Google Contacts and Calendar once, read-only, and hand you a small ranked set of people to confirm. After that it lives on your breadcrumbs.

In my notes I described the design as calm by construction: no alarm colors, no streaks, no overdue counters. That was a rule, not a mood. The failure mode of every productivity tool is that it turns care into a chore with a guilt meter attached. Tend is not allowed to do that.

The layer below: the hard parts you can't see

Tend looks small. A few screens, a text box, a kind list. The engineering that matters is underneath, and all of it takes the shape of a promise the app must never break. I wrote these down while building, because they were the actual specification.

• Never drop a heartfelt note. The model that parses your sentence will sometimes fail: no key, an error, a slow response. When it does, Tend falls back to a simple deterministic reading and, if it's still unsure, saves the note as a new entry anyway. A duplicate is recoverable. A lost note about someone you love is not. That asymmetry decides the whole design.
• Never silently merge two people who share a first name. There are two Sarahs. If Tend guesses wrong and fuses them, it has corrupted your memory of both. So matching uses a similarity score, and a bare first name only ever suggests. An ambiguous match asks you to confirm instead of quietly merging.
• Never turn "last fall" into a calendar date. Human time is fuzzy, and pretending otherwise is a lie the software tells you later. Dates carry a kind (exact, recurring, approximate, seasonal) and keep the words you actually said, so "sometime last fall" stays "sometime last fall."
• Your words win, permanently. The moment you hand-edit what matters about someone, the model stops touching it. A model does not get to overwrite a sentence you wrote by hand about a person you love.

Notice what these have in common. None is a hard programming problem. They're judgment problems: knowing that a lost note is worse than a duplicate, that a fake date is worse than a fuzzy one, that a person's own words outrank a model's summary. I didn't need to be a good engineer to hold those opinions. I've been a person with friends my whole life. What changed is that I can now enforce them in working software, with tests that prove the note survives when the model falls over. I built Tend over about nine days in June, in phases I could stop between, with the promises above written down before any code. The taste for what the software should refuse to do was mine. The typing was the cheap part.

What building it taught me

The care is in the parts you can't see. The visible app is small on purpose. Trust is built in the invisible guarantees, not the visible features. I suspect that's true of most software made for humans.

Judgment is the scarce input now. Every one of Tend's hard parts started as a sentence about what matters, not a technical challenge. When building is cheap, knowing what to protect becomes most of the work. I argued the general version of this in The Layer Below; Tend is the tender version.

Calm is a feature you have to defend. Streaks and counters would have been easy to add. They're the defaults, and they "drive engagement." Leaving them out took effort. The restraint is the design.

The honest gap

I can't show you a wall of active users, because I don't have one. Tend runs on demo data as much as real data. The only proof that matters for a tool like this is whether I reach out more than I used to, and that's a question I'd rather answer after a year than after a month.

The stress test I hold it to: does the calm ever become permission to disengage? A tool that gently reminds you to call your sister is good. A tool that makes you feel you've done something by logging that you should is a trap. Tend is only worth anything if it moves the check-in from the app into the world. The measure isn't notes captured. It's calls made.

Close

A calendar remembers the date and forgets whose it is. That is the gap Tend lives in. It doesn't fix drifting with discipline or guilt. It carries the remembering, so that when you have a free minute the right person is already at the top of a short, kind list, and all you have to do is the one thing no software can do for you.

Reach out. That was always the point.