William Dekou

Beyond the known!

[Peter Yang @petergyang]

Airbnb has a blueprint of their entire customer journey on their office walls.

They then map all product, policy, and service updates to it.

More companies should do this to avoid shipping the org chart.

[Sundar Pichai @sundarpichai]

Seeing some qs on what Gemini *is* (beyond the zodiac :). Best way to understand Gemini’s underlying amazing capabilities is to see them in action, take a look ⬇️

[TheElimbyshow @MrsBlife]

À LA RECHERCHE DE DONNEURS DE SANG POUR DEMAIN À L’HÔPITAL GÉNÉRAL DE DOUALA, TOUTES AIDES EST LA BIENVENUE. RETWEET POUR SAUVER UNE VIE 🤲🏾

[Sahn Lam @sahnlam]

How Discord Stores Trillions of Messages

In 2015, Discord started using MongoDB to store messages. By November 2015, there were already 100 million messages that did not fit in RAM, causing unpredictable latency.

In 2017, Discord moved to storing billions of messages in a Cassandra database. By 2022, the number of stored messages had ballooned to trillions across 177 nodes.

But Cassandra was plagued by several serious issues.

- Hot partitions occurred when a small number of high traffic channels overwhelmed nodes, cascading latency across the cluster.

- Garbage collection pauses created latency spikes.

- Compactions fell behind, forcing expensive reads to query multiple SSTables.

- Maintenance like node repairs interrupted service.

Discord migrated to ScyllaDB for the following benefits:

- Written in C++ instead of Java, eliminating disruptive garbage collection pauses

- Shard-per-core model provides stronger workload isolation to prevent hot partitions from cascading latency across nodes.

- Reverse query performance optimized to meet Discord's needs

- They reduced nodes to 72 while increasing disk space per node to 9TB.

To further protect ScyllaDB, Discord:

- Built intermediary data services in Rust that limit concurrent traffic spikes

- Data services sit between the API and database, coalescing requests

- Query the database just once even if multiple users request the same data

- Rust provided fast, safe concurrency ideal for this workload

The results? Tail latencies down from 40-125ms to a steady 15ms. Database uptime improved from weekend-long outages to smooth sailing. The system easily handled World Cup traffic spikes, processing events like goals and penalties without breaking a sweat. Discord continues to scale, now reliably storing trillions of messages with ScyllaDB.

–
Subscribe to our weekly newsletter to get a Free System Design PDF (158 pages): https://t.co/kNfv0DVDdf

[William Dekou @wdekou]

@jm_heacock Congrats 👏🏾👏🏾👏🏾

[Sahn Lam @sahnlam]

How Discord Stores Trillions of Messages

In 2015, Discord started using MongoDB to store messages. By November 2015, there were already 100 million messages that did not fit in RAM, causing unpredictable latency.

In 2017, Discord moved to storing billions of messages in a Cassandra database. By 2022, the number of stored messages had ballooned to trillions across 177 nodes.

But Cassandra was plagued by several serious issues.

- Hot partitions occurred when a small number of high traffic channels overwhelmed nodes, cascading latency across the cluster.
- Garbage collection pauses created latency spikes.
- Compactions fell behind, forcing expensive reads to query multiple SSTables.
- Maintenance like node repairs interrupted service.

Discord migrated to ScyllaDB for the following benefits:

- Written in C++ instead of Java, eliminating disruptive garbage collection pauses
- Shard-per-core model provides stronger workload isolation to prevent hot partitions from cascading latency across nodes.
- Reverse query performance optimized to meet Discord's needs
- They reduced nodes to 72 while increasing disk space per node to 9TB.

To further protect ScyllaDB, Discord:

- Built intermediary data services in Rust that limit concurrent traffic spikes
- Data services sit between the API and database, coalescing requests
- Query the database just once even if multiple users request the same data
- Rust provided fast, safe concurrency ideal for this workload

The results? Tail latencies down from 40-125ms to a steady 15ms. Database uptime improved from weekend-long outages to smooth sailing. The system easily handled World Cup traffic spikes, processing events like goals and penalties without breaking a sweat. Discord continues to scale, now reliably storing trillions of messages with ScyllaDB.

–
Subscribe to our weekly newsletter to get a Free System Design PDF (158 pages): https://t.co/kNfv0DVDdf

[Cyprien TANKEU @Cyprien_T]

Ce samedi à 11h aura lieu la 3e séance de la préparation à la Certification Google Cloud Professional Data Engineer avec notre facilitateur @wdekou, Strategic Cloud Engineer chez @Google.
La séance aura lieu exclusivement en ligne.
Via https://t.co/qyF4wY8oTx
#Cloud #data #GDG

[Vala Afshar @ValaAfshar]

This is how we checked email in 1984

[Aleksandr Volodarsky @volodarik]

There's a $4B startup that:

• raised 0 funding
• spends 0 on marketing (11M users came organically)
• If today revenue goes to 0, it will still have 13 yrs of runway 🤯

Here's a story you never heard of:

[Luke Sophinos @lukesophinos]

Myspace achieved 1,000,000 users in one month, while Facebook took a year to get there.

At one point, Zuckerberg tried to sell Facebook to them for only $75M & they refused.

At $800M in revenue, and a $12B valuation, Myspace still failed.
Here's why 👇

[The Cameroonian 🇨🇲 @TheCameroonianZ]

Le but de Vincent Aboubakar face à MKE Ankaragücü.

#Cameroon #besiktas
https://t.co/q1VlV2thoC

[William Dekou @wdekou]

Et je vous ai écrit en privé sur Twitter sans succès 🥲 @Orange_Cameroun

[William Dekou @wdekou]

Un service client qui n'a pas de respect du temps de ses clients @Orange_Cameroun. Quel dommage !
Le 13 Janvier 2023, il aurait fallut attendre 4 heures de temps pour se faire servir. J'ai dû partir au bout de 2 heures d'attente et utiliser la SIM d'un proche comme alternative.

[William Dekou @wdekou]

Aujourd'hui de retour pour avoir accès au service client, ça fait déjà 1h54 d'attente et toujours pas servi
@Orange_Cameroun

[William Dekou @wdekou]

2 ans après, je suis entrain de me refaire le replay du Justicier de Nkoabang.
Juste un magnifique cette série camerounaise!

https://t.co/EKeClXKaDt

[Tina Songue @tinasongu3]

Quand tu sors du Cameroun et que tes pieds et tes yeux atterrissent dans un pays développé, puis tu te souviens de ce qu'on fait de l'argent du contribuable dans ton pays, tu vois cmt il est sale et sous-développé, cmt l'eau, l'eau, l'eau courante est un luxe...

[Sahil Bloom @SahilBloom]

Things I'd like to tell my 20-year-old self:

[William Dekou @wdekou]

Il est hors de question que pour t’examiner au urgence, il faille d’abord aller payer les gants.

L’hôpital devrait avoir son stock de gants pour les urgences

[William Dekou @wdekou]

Je suis meurtri par la façon dont les urgences à l’hôpital fonctionnent. Il suffit d’y arriver inconscient ou sans argent pour y ressorti les pieds devant. Et il faut que cela change pour notre vie et celle de nos proches #cameroun #yaounde #douala

[Andrew Ng @AndrewYNg]

If you're starting a reading group on Large Language Models (LLMs), what is one research paper you will want added to the reading list?

Researchers: Feel free to recommend your own paper too!

[William Dekou @wdekou]

@Benjamin_moukan Merci, c’est chaleureux d’être prêt de ses proches. En passant, serait à Po en Mars

[William Dekou @wdekou]

Je suis meurtri par la façon dont les urgences à l’hôpital fonctionnent. Il suffit d’y arriver inconscient ou sans argent pour y ressorti les pieds devant. Et il faut que cela change pour notre vie et celle de nos proches #cameroun #yaounde #douala