The engineering team at Zerodha, India's largest stock broker, writes about scaling, PostgreSQL, logging, PDF generation, and remote work.
HN commenters cite it as a model of lean engineering, citing its small team serving millions of users, its logging setup, and its move to Typst.
* ~1200 staff, ~10 years
* tech team is 30 members (two mobile developers, two designers, two frontend developers, one test engineer, one devops engineer, and one department liaison, the rest fullstack developers). Nobody had any background in finance, and most had no prior work experience either. Everyone has been a hacker or a hobbyist straight out of college.
* became the largest stock broker in India in January 2019
* never raised external funding, have zero debt, and have been profitable YoY
* no marketing team, no advertising
* 15-20% of Indian retail trade and investment volumes
* ~1 million daily active users, $3 billion in volumes, busy day ~7 million trades
* broadcast ~16 million market ticks per second: careful byte-by-byte optimisations so bandwidth bills are negligible
Tech stack:
* Go. Python for non-realtime data-heavy backoffice systems, bit of C++ and Java for special cases
* VueJS
* Flutter (previously tried native Android/Java, Swift, and React Native). Edit: https://zerodha.tech/blog/from-native-to-react-native-to-flutter/
* Postgres. Edit: https://zerodha.tech/blog/working-with-postgresql/
* Redis, Haproxy, Nginx, Kafka, Elk
* Dev: Self-hosted Gitlab, RunDeck, RocketChat, Metabase, Phabricator, Postal. Sentry, Grafana, and Prometheus. Edit: https://zerodha.tech/blog/infra-monitoring-at-zerodha/
* Servers: physical rack + AWS
* ERP: erpnext.com (open source)
Edit: Is very summary. Much information article is. Article read if confused…
Right, So is that why Discord was successful in using 'React Native' (RN) and also was able to implement the same features (Stage Channels) faster than Clubhouse (iOS only in early 2021) did for their Android users at the time?
Or is that why Coinbase announced a successful transition to RN [0] given the metrics they outlined in their blogpost? Perhaps is that also why when it comes to needing high performance, the largest stock broker in India (Zerodha) went from Native to RN and settled on using Flutter? [1]
Why didn't they go back to native then? The problem with this article is that it is from an unrealistic and absolutist perspective. Just look at this nonsense:
> And if you ever need to share code between your iOS and Android apps, you can always use C++; which was the solution adopted by Dropbox for almost a decade.
And a decade later, is even Dropbox using their own solution today? Why is it archived then? [2] When they needed to share code between their native iOS and Android, apps why did they go back to native? [3]
The author is not being realistic. His suggestions are more of an expensive solution that gets your greenfield project to market at a slower rate as demonstrated by Clubhouse. Is that what you want?
[0] https://blog.coinbase.com/announcing-coinbases-successful-transition-to-react-native-af4c591df971
[1] https://zerodha.tech/blog/from-native-to-react-native-to-flutter/
[2] https://github.com/dropbox/djinni
[3]…
1. I think AGPL is a good license for web apps that can also dissuade Elastic/Mongo-like fiascos. Mastodon, Metabase, Grafana, Minio etc. are AGPL and are widely used.
2. We see ourselves as a group of hackers and not really as a corporate entity. Many projects that come out of our team are largely individual efforts. For instance, I have spend considerable personal time working on listmonk over the last couple of years just because I like it. There is no Zerodha mandate involved. Only projects that have to be branded as Zerodha or involve a lot of multi-dev effort go under the official handle (ref: https://zerodha.tech/projects)
3. listmonk offers a one-click Heroku button (a bunch of simple scripts really), so it should just be a matter of creating deployment scripts for other platforms as well. I have not looked into it personally.
If you should decide to go inhouse, I can warmly recommend checking the *frappe framework*, with which the open-source ERPNext was built. Compared to other such things this is truly open source (not like odoo and others, which really try to catch you in with being "open-source" and then let you pay up for the features you really need).
It is very powerful and comes with so many batteries included and is actually quite fun to develop with.
https://frappeframework.com/
Here is a story of a big financial institution betting on inhouse dev using frappe. (There is a TLDR on the bottom of that page ;) )
https://zerodha.tech/blog/being-future-ready-with-common-sense/
All the best <3
Just want to say thanks for creating Vector. We use it heavily at Zerodha and wrote about our setup here: https://zerodha.tech/blog/logging-at-zerodha/
It replaced both Filebeat and Logstash for us with a single binary that actually has sane resource usage (no more JVM nightmares). VRL turned out to be way more powerful than we could imagine - we do all our log parsing, metadata enrichment, and routing to different ClickHouse tables in one place. The agent/aggregator topology with disk buffering is pretty dope.
Genuinely one of my favorite pieces of infra software. Good luck with Tero.
I stumbled upon this while checking out Listmonk[0], and reading through the ZERODHA blog (a post on postgres was nice[1]), and was pretty impressed by how light but effective this pattern was -- writing read results to a temporary database is something I hadn't seen before, and is quite an interesting way to solve the problem of scaling large read queries, though it's probably not the first one would think of (probably that would be scaling up or adding read replicas).
[0]: https://listmonk.app/
[1]: https://zerodha.tech/blog/working-with-postgresql/