Hey there!
Summary of this email:
- Should we stop using subagents?
- 10 seats left for the AI Workshop for devs on November 26
- Event Bus in Kafka course 100% published
- Café con Codely recap (watch it here)
- The joke of the week
🤔 Should we stop using subagents?
Last Thursday Anthropic published a very interesting post about the use of subagents.
The summary is that a single agent with skills usually gets better results than an orchestrator with many specialist subagents, and also with lower cost and latency.
Why? Because every time a subagent hands its result to another one (what is called a handoff), context gets lost along the way. With a single main agent, you avoid this.
This was different a few months ago. Today's models can handle more context and longer sessions. According to Anthropic, the change started to show from Opus 4.5 onward.
Their rule to split the pieces:
- 📚 Skills: how your team works. Steps, rules and judgment that used to live in the prompt of each subagent. And if you don't use skills, the project documentation also does this job.
- 🔧 Tools and MCP: what the agent does or checks outside its context. For example, create an issue, read the current status of an order or return a result.
- 🤖 Subagents: only for parallel work, to isolate context or when a single agent can't cope.
The summary is to use subagents when you need them for context reasons. An example would be "search the whole repo for where this function is used and give me the list". The subagent reads many files in its own context, and the main agent only gets the list.
If your subagents look like your org chart (a frontend agent, a backend one, a QA one…), that's Conway's law applied to agents, and that's exactly what the post says doesn't scale.
And it's not only Anthropic. A paper from this month compares Codex, Claude Code and Kimi Code with and without parallel subagents on 354 tasks. On SWE-bench Verified, Claude Code drops from 83% to 59% when it spawns subagents, and overall they use between 1.4 and 3.3 times more tokens.
That said, don't make the change blindly. Anthropic insists on building evals before you remove any subagent and on removing them one at a time. In their example, removing one cut latency, but the agent failed in one out of every two runs.
We will talk about these topics in the AI Workshop for devs. Which, by the way, only has half of its seats left.
🤖 10 seats left for the AI Workshop for devs
The new edition of the AI Workshop for devs is on Thursday, November 26. Only 10 seats left.
We cover things like the ones we discussed earlier in this newsletter. In short, how to keep shipping reliable software without lowering the quality.
And remember that the price goes up as the seats sell out. 🙌
📯 Event Bus in Kafka course 100% published
We have published the Event Bus in Kafka course 100% on Codely Pro Standard.
In the last part we cover:
- 🔁 Error handling with Kafka's native retries, exponential backoff and dead letter.
- ♻️
renewto extend the timeout when a message takes longer than expected to process. - ⚡ More than one consumer per partition, the historical Kafka limitation that Kafka Queues solves.
If you already have Kafka in your infrastructure, it's probably the best option to build your Event Bus. You don't need to add another broker. 😊
☕ Café con Codely recap
This is the top 3 of headlines we discussed in the latest Café:
- PHP2Shell: two critical PHP vulnerabilities take half the Internet offline. They let anyone run code without a login, they score 9.2, and according to Censys 1.5 million servers run a version without the fix.
- Addy Osmani: the bottleneck is not writing code anymore, it is verifying it. To get quality output from your agent, give it a way to verify its work, and tests are part of that way.
- Arc: The Browser Company shuts it down on December 22. As alternatives you have Zen, based on Firefox and inspired by Arc, Firefox itself with vertical tabs, or Helium if you want to stay on Chromium.
You have the full Café recap with links to each story at the moment we discussed it.
Tomorrow we will be live at 9 CET discussing this week's news on Café con Codely. On our YouTube, Twitch and X. 🙌
And since you've made it to this part of the newsletter, here's the joke of the week, which I know you were waiting for:
Why is the God Object depressed? Because it has too many responsibilities! 😂 😂 😂
Cheers!