Sprint 5: Email Notifications (Weeks 11–12)

The platform works, but it is silent. Applicants submit an application and have no idea what happens next. Sprint 5 closes that loop with transactional email.

Sprint goal

Applicants receive a confirmation email when they apply. When an admin updates their status, they receive a status change email.

Design decision (Tech Lead + DevOps own this before sprint starts)

Open an issue and decide:

1. SMTP provider: use Mailgun, Resend, or a raw SMTP server?
   • Recommended: Resend (free tier, simple API, Python SDK)
2. Sending strategy: synchronous (blocks the request) or async (background task)?
   • Recommended: FastAPI BackgroundTasks so the HTTP response is not delayed
3. Testing strategy: how do we test email in CI without sending real mail?
   • Recommended: dependency injection — swap the real sender for a no-op in tests

Close the issue with an email-design.md doc before engineers start work.

What each role ships this sprint

Backend

Add email sending as a background task:

# app/email.py
from fastapi import BackgroundTasks

def send_confirmation(background_tasks: BackgroundTasks, to: str, job_title: str) -> None:
    background_tasks.add_task(_send, to, subject=f"Application received — {job_title}", ...)

• Hook into POST /jobs/{id}/apply
• Hook into PATCH /applications/{id}/status
• Read SMTP credentials from environment variables only — never hard-code

Add this package (or whichever provider is chosen):

uv add resend

Frontend

• Add a visible confirmation message after applying: "A confirmation email has been sent to {email}"
• Update the application status dropdown to show a spinner (HTMX htmx-indicator) while the PATCH is in flight

QA

Do not send real email in tests. Override the email dependency:

@pytest.fixture
def client_no_email(client):
    sent = []
    app.dependency_overrides[send_email] = lambda *a, **kw: sent.append((a, kw))
    yield client, sent
    app.dependency_overrides.clear()

Write tests that assert the email task was queued (not that it was delivered).

DevOps

• Add RESEND_API_KEY (or equivalent) to Render environment variables
• Add a dummy RESEND_API_KEY=test secret to the CI workflow so tests pass without real credentials
• Document the full list of required environment variables in CONTRIBUTING.md

Tech Lead

• Write docs/email-design.md before sprint coding starts
• Review all email PRs for credential hygiene (no keys in code, no keys in logs)
• Ensure the email function is behind a dependency so it can be overridden in tests

PM

• Write the email copy (subject line and body text) as a GitHub issue — the team will implement it
• Track: backend email must merge before QA can write integration tests

Environment variables reference

Variable	Example	Where it goes
RESEND_API_KEY	re_abc123	Render env, CI secret
FROM_EMAIL	noreply@techhire.example.com	Render env, CI secret
APP_URL	https://cs408.onrender.com	Render env

References

• FastAPI Background Tasks
• Resend Python SDK
• HTMX loading indicators

Sprint 5 checklist

• [ ] docs/email-design.md is merged before sprint coding starts
• [ ] Confirmation email is sent on application submit (verify on deployed site)
• [ ] Status-change email is sent when admin updates status
• [ ] No API keys appear anywhere in the codebase or CI logs
• [ ] Email tests pass without real credentials
• [ ] You have 2+ merged PRs
• [ ] You have given 2+ reviews