Hacker News submission template#

When you’re ready to post the blog (2026-06-21-lessons-from-shipping-a-100pc-coverage-payment-library.md) to Hacker News:

Title (≤ 80 chars; HN truncates harder than that)#

Show HN: Lessons from shipping a 100% coverage ISO 20022 payment library

Alternates if the above feels too long after publishing:

  • Lessons from shipping a 100% coverage payment library

  • Pain001 v0.0.53: a 100% coverage ISO 20022 payment suite

  • Show HN: A coordinated-release 4-package ISO 20022 suite (Python)

URL#

Point to the blog post on whatever you publish to:

  • If on your own domain: https://sebastienrousseau.com/posts/lessons-from-100pc-coverage

  • If on GitHub Pages: https://sebastienrousseau.github.io/pain001/posts/2026-06-21-lessons-from-shipping-a-100pc-coverage-payment-library.html

  • If on Substack / Dev.to / Medium: the canonical post URL

Pick one URL and stick with it. HN dedupes by URL; if you’ve already submitted a similar URL before, it gets quietly marked “duplicate” and never reaches the front page.

When to post#

Tuesday or Wednesday, 9am UTC (≈ 5am US East / 2am US West / 10am London / 5pm Tokyo). That’s the peak overlap of European morning + US morning. Posts at this window reliably outperform weekend posts 3-5x on the same content.

Avoid:

  • Friday afternoon (US, dead zone)

  • Saturday / Sunday (engaged-reader crowd shrinks)

  • Holidays (Memorial Day, July 4, Thanksgiving week, Dec 22 - Jan 3)

First-comment template#

Within 30 seconds of posting, post the first comment yourself — this acts as a “what to talk about” prompt and reliably 2x’s the engagement. Don’t editorialise; ask a question.

Author here. Three things I'm genuinely uncertain about and would
love this crowd's pushback on:

1. The pragma rule. I require every `# pragma: no cover` to carry
   a one-line justification. In ~3000 lines I have 11 of them.
   Is that the right shape, or am I over-thinking the "is 100%
   meaningful?" question?

2. The plugin contract. I went 53 patch releases before formalising
   it, then had to migrate every existing loader/scheme/writer.
   Should plugin substrates be in the v0.0.1 of any infrastructure
   library that wants to outlive its first maintainer?

3. The bus factor. I've been "inviting" co-maintainers in
   GOVERNANCE.md for >1 year and that's done nothing. Today I
   sent the first concrete recruitment DM. Has anyone successfully
   recruited an OSS co-maintainer? What worked?

Repo: https://github.com/sebastienrousseau/pain001
Suite: https://pypi.org/project/pain001/ + pain001-mcp + pain001-lsp + pain001-loader-xlsx

What to do during the post’s first hour#

The post lives or dies in the first 60 minutes. After that, HN’s ranking algorithm caps how high it can climb without a sustained upvote rate.

Open the post in a tab and refresh it every 5-10 min. Reply to every top-level comment within 15 min. Don’t be defensive. HN rewards “you’re right, I should clarify that” far more than “actually, you’ve misunderstood.” If a critic has a point, say so in public and update the post (note: “edit:” with a timestamp).

What NOT to do#

  • Don’t post to /r/programming, Twitter, LinkedIn at the same time — HN penalises posts that look like coordinated drives. Stagger: HN first, Twitter/LinkedIn 6-12 hours later once HN ranking is established.

  • Don’t ask friends to upvote. HN’s spam detection is good; detected coordinated voting drops the post permanently.

  • Don’t link to your repo, your Twitter, or anything else in the body of the post. HN strips most of those anyway, and the ones that survive read as self-promotion. Links go in the first comment, not the post.

After the post#

Within 48 hours, regardless of whether it hits front page:

  1. Update the post’s “companion HN thread” link with the actual HN URL (currently # placeholder).

  2. Update the project README with a “Pain001 was on Hacker News today: [link]” line — drives a second wave of traffic.

  3. Open one issue per genuine criticism from the HN comments. They’re the most-rigorous critique you’ll get for free; honour them with action.

Submission tracker#

Field

Value

Posted at

2026-MM-DD HH:MM UTC

HN URL

https://news.ycombinator.com/item?id=…

Peak rank

#_ on front page_

Upvotes after 24h

N

Top critique to act on

summary

Fill in once posted.