Paper Doc Tutoring

A two-person company that needs to behave like a bigger one

My co-founder tutors — AP prep, SAT prep, college admissions. She is the entire delivery capacity of the business. Every hour she spends on scheduling, invoicing, chasing payment, or formatting a practice test is an hour she is not teaching, and there is no second tutor to absorb it.

That constraint set the product strategy. Not "what would a tutoring platform have", but: what work can software take off the one person who cannot be duplicated?

How it fits together

Selling time, then tracking it

Lesson packages sound simple and are not. Three group sizes — one student, two to three, four to ten — across single lessons, five-packs and ten-packs. Nine products, priced separately, all drawing down against the same finite resource: my co-founder's calendar.

I chose to track everything in minutes rather than lessons. A "lesson" is not a fixed unit once you allow different durations and group sizes, and the moment you let someone use half a credit, a lesson-denominated balance starts lying to you.

-- FIFO across credit lots. Returns the lots touched so the usage log
-- can show exactly which purchase paid for which lesson.
create or replace function consume_lesson_minutes(
p_student_id uuid,
p_minutes    int
) returns table (lot_id uuid, minutes_taken int)
language plpgsql as $$
declare
remaining int := p_minutes;
lot       record;
begin
for lot in
  select id, minutes_remaining
  from lesson_credit_lots
  where student_id = p_student_id and minutes_remaining > 0
  order by purchased_at asc
  for update
loop
  exit when remaining <= 0;
  lot_id        := lot.id;
  minutes_taken := least(remaining, lot.minutes_remaining);

  update lesson_credit_lots
     set minutes_remaining = minutes_remaining - minutes_taken
   where id = lot.id;

  remaining := remaining - minutes_taken;
  return next;
end loop;

if remaining > 0 then
  raise exception 'insufficient balance: % minutes short', remaining;
end if;
end;
$$;

Unused hours do not expire. That is a deliberate trust decision rather than an oversight — expiring credits is a good revenue lever and a bad look for a business whose entire growth mechanism is parents recommending it to other parents.

The authoring problem

The test editor started as one component and grew until editing it was frightening. TestEditor.jsx and ProctoredTestShell.jsx both crossed the line where a change in one place broke something two screens away.

I split both into focused sub-components against a shared helpers module — StimulusRow, QuestionRow, StimulusImageUpload on the authoring side; IntroScreen, ActiveTestView, QuestionPanel, ResultsScreen, StimulusBanner, ImageLightbox, ExplanationSection on the student side.

The bigger authoring win was upstream. Test content arrives as Word documents, so I built an importer with a deterministic label-prefix parser — Q:, TYPE:, OPTIONS: — plus a downloadable .docx template so authors write in a shape the parser can read.

const LABELS = ['Q', 'TYPE', 'OPTIONS', 'ANSWER', 'EXPLAIN_CORRECT', 'EXPLAIN_INCORRECT'];

export function parseBlock(raw) {
const fields = {};
let current = null;

for (const line of raw.split('\n')) {
  const match = line.match(/^([A-Z_]+):\s?(.*)$/);
  if (match && LABELS.includes(match[1])) {
    current = match[1];
    fields[current] = match[2];
  } else if (current) {
    fields[current] += '\n' + line;   // continuation, not a new field
  }
}

if (!fields.Q) throw new ParseError('block has no Q: line', raw);
return normalise(fields);
}

The exam runtime

A proctored test is a small real-time application: timing, anti-cheating flags, a stimulus that has to stay visible while the questions scroll, and an answer reveal that is configurable between immediate and end-of-test.

• Per-question time is tracked into a question_time_spent JSONB column on test_attempts — a variable-length structure that would be miserable as rows, and that we only ever read as a unit.
• The stimulus side panel scrolls independently and full-height, with a layout: 'side' | 'inline' field so a long passage and a small diagram can be presented differently.
• Layout had to hold from a wide desktop down to a phone. The stimulus and question stay visible at every width; the question-number nav collapses first.

What I would tell you if you asked in an interview

Where it landed

• REVISE: hours sold / students enrolled since launch
• REVISE: time to author a full practice test, before vs. after the Word importer
• Scope cut to lesson packages for launch; tests and video deferred behind feature flags