Top all-time · #5102
Recall.ai
Company blog · recall.ai · on HN as davidguprogrammingsystems
Recall.ai is the company blog at recall.ai, writing about programming and systems. Since 2023, 15 different Hacker News readers have linked it 28 times, most often “Postgres LISTEN/NOTIFY does not scale”. No feed was found, so read it on the site itself.
Too few sampled comments (9) to say how often HN recommends it.?
Why HN links it
Recall.ai blog posts on Postgres LISTEN/NOTIFY scaling, cited across HN threads on using Postgres for queues and messaging. Mostly linked as background for those discussions.
Summarised by Claude from a sample of 9 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Get transcripts, recordings, and metadata from Zoom, Google Meet, Teams, and more. Meeting Bot API, Desktop SDK, and Calendar API with 99.9% SLA.
Most-linked posts?
- Postgres LISTEN/NOTIFY does not scale9 people · 9 mentions · first linked 2025-07-07
- Reducing latency with esoteric Linux process flags3 people · 3 mentions · first linked 2025-03-01
- WebSockets cost us $1M on our AWS bill2 people · 2 mentions · first linked 2024-11-05
What Hacker News says?
If you're looking to build an AI notetaker for medical use-cases (or others), https://www.recall.ai is a HIPAA compliant API to capture conversations from video conferences. P.S. I'm the founder, so obviously biased :)
Comment linking /
on “Ontario family doctor says new AI notetaking saved her job”Submitted Postgres LISTEN/NOTIFY does not scale as a story · 574 points
HN discussionI want an app that uses the accessibility API to plug into Meta, Snap, etc and gives you full control over your socials ala Recall using LLMs. I feel like Gen AI is the countermeasure to closed social ecosystems trying to treat you as the product. Ingest everything my social users have access to, and let me control the experience (Recall meets Buffer?). Scraping is old and busted, consuming the firehose available to…
Comment linking /
on “Meta Wants More AI Bots on Facebook and Instagram”Submitted WebSockets cost us $1M on our AWS bill as a story · 362 points
HN discussionYour version makes sense. I understood the OP's approach as being different. Two (very, if indexed properly) short transactions at start and end are a good solution. One caveat is that the worker can die after t1, but before t2 - hence jobs need a timeout concept and should be idempotent for safe retrying. This gets you "at least once" processing. > this obviously has the drawback of knowing how long to sleep for; a…
Comment linking /blog/postgres-listen-notify-does-not-scale
on “Replacing cron jobs with a centralized task scheduler”Submitted Debugging audio artifacts caused by... a serial port? as a story · 56 points
HN discussionI'm obviously biased as the founder, but check out https://recall.ai/ for a meeting bot API. We serve over 300 companies, process millions of hours of recording a year, and are officially partnered with Zoom.
Comment linking /
on “Ask HN: Has Anyone Trained a personal LLM using their personal notes?”Submitted Reducing latency with esoteric Linux process flags as a story · 29 points
HN discussionFeels tidier till it becomes a bottleneck: https://www.recall.ai/blog/postgres-listen-notify-does-not-s...
Comment linking /blog/postgres-listen-notify-does-not-scale
on “How/why to sweep async tasks under a Postgres table”Submitted Pdeathsig is almost never what you want as a story · 27 points
HN discussionIt did fix the original "Postgres LISTEN/NOTIFY does not scale" [1] post's problem though, which was mentioned in an update of that article: Update: Fixed in Postgres core This commit has eliminated the bottleneck in the postgres core. Credit to Joel Jacobson and the core postgres contributors for resolving this. [1] https://www.recall.ai/blog/postgres-listen-notify-does-not-s...
Comment linking /blog/postgres-listen-notify-does-not-scale
on “Postgres LISTEN/NOTIFY actually scales”Submitted How WebSockets cost us $1M in AWS spend as a story · 8 points
HN discussionMore context: https://www.recall.ai/blog/postgres-listen-notify-does-not-s...
Comment linking /blog/postgres-listen-notify-does-not-scale
on “Just Use Postgres for Durable Workflows”Submitted Forking Chromium to Bolt on a High-Throughput Shared Memory Ringbuffer as a story · 7 points
HN discussionThis is largely because LISTEN/NOTIFY has an implementation which uses a global lock. At high volume this obviously breaks down: https://www.recall.ai/blog/postgres-listen-notify-does-not-s... None of that means Oban or similar queues don't/can't scale—it just means a high volume of NOTIFY doesn't scale, hence the alternative notifiers and the fact that most of its job processing doesn't depend on notifications at a…
Comment linking /blog/postgres-listen-notify-does-not-scale
on “I Love You, Redis, but I'm Leaving You for SolidQueue”Submitted Reducing Latency by 83% with Esoteric Linux Process Flags as a story · 6 points
HN discussionlink for all others - this commenter fixed a bug in core Postgres that fixed a scaling issue in actual listen/notify https://www.recall.ai/blog/postgres-listen-notify-does-not-s...
Comment linking /blog/postgres-listen-notify-does-not-scale
on “Show HN: Honker – Postgres NOTIFY/LISTEN Semantics for SQLite”Submitted Encountering Hyrum's Law in the Wild as a story · 6 points
HN discussionPeople say you don’t need Redis, you can just use Postgres LISTEN/NOTIFY. I read a blog post about it locking the entire database and causing problems[0]. Apparently it’s fixed now but this only just being discovered in 2025 doesn’t give me confidence it’s battle tested for prod. At some point shoving everything into Postgres is an anti pattern too. [0]: https://www.recall.ai/blog/postgres-listen-notify-does-not-s...
Comment linking /blog/postgres-listen-notify-does-not-scale
on “You Just Need Postgres”Submitted Postgres locks do not scale as a story · 4 points
HN discussionRunning a high-scale postgres in production is fraught. We have a really demanding workload and have hit a lot of undocumented performance cliffs. Most of these stem from fundamental design flaws in postgres [0][1]. I'm glad to see projects like this trying to using new tools to improve upon these deeply rooted issues that was just not practical even 12-18 months ago. This is really ambitious and I'm excited to see…
Comment linking /blog/postgres-listen-notify-does-not-scale
on “Show HN: Pgrust, Postgres in Rust (passing 100% of Postgres regression tests)”Submitted Postgres Postmaster does not scale as a story · 4 points
HN discussionSubmitted The fix for a segfault that never shipped as a story · 4 points
HN discussionSubmitted Reducing Latency by 83% with Esoteric Linux Process Flags as a story · 4 points
HN discussionSubmitted Debugging a 1 in 36M segfault in our audio encoder as a story · 2 points
HN discussionSubmitted Pdeathsig is almost never what you want as a story · 1 points
HN discussionSubmitted Zoom RTMP live streaming API pros and cons as a story · 1 points
HN discussion