Recent content on Serghei's Blog
You already run Claude Code by hand: copy issues into a prompt, watch it work, check the diff, and if something breaks halfway through, you restart it. This works fine for one task at a time, but it falls apart when you have 10 tasks simultaneously. 
 Claude Code is good at handling routine engineering tasks: bug fixes, dependency bumps, and small features, when the prompt is clear and the…
If you have ever built a RAG pipeline, you have probably faced the same awkward problem: BM25 returns a list of documents with scores like 18.3 , your vector index returns another list with cosine similarities between 0 and 1 , and somebody on the team asks the obvious question — how do we merge these into one ranking? The naive answer (“normalize and add them up”) is wrong in…
Every TypeScript project starts clean. A few interfaces in a types/ folder. A couple of shared shapes for API responses. Then six months pass. The folder has fifteen files, three naming conventions, and nobody can explain why ContactDetail lives in src/types/contact.types.ts while SettingsBusinessProfileSnapshot lives in src/app/(dashboard)/settings/settings-view-model.ts . Both are view models.…
Coding agents can write code. That capability is real. Point Claude Code or Copilot at a well-scoped issue and you get a working pull request most of the time. Now try running five of them unattended. A class of failures appears that has nothing to do with how well the agent writes code. I spent the past month building a Go project. Agents handled issue implementation; I handled architecture and…
When teams pick a language for a new project, the criteria are familiar: hiring pool, ecosystem maturity, team familiarity, IDE support. When your primary developer is a coding agent, most of those criteria become irrelevant. The agent has no language preference. It needs no IDE plug-ins. Different factors take over: how well the model knows the language, how parseable the error messages are, how…
Last month I ran Claude Code on 12 GitHub Issues simultaneously. Three of them tried to modify the same file. Two got stuck in retry loops with no backoff. One silently burned through $40 in API tokens before I noticed it was hallucinating the same test fix over and over. By the time I untangled the mess, I had spent more time babysitting agents than I would have spent writing the code myself.

 Build once, deploy everywhere. Skills are the universal way to teach AI agents how to do your team’s work. 
 
 
 What problem do skills solve? # 
 
 AI agents are increasingly capable, but they lack the context they need to do your work reliably. They do not know your team’s conventions, your internal tools, your deployment process, or your testing strategy.…
Introduction # 
 
 Why Emacs? # 
 
 Emacs is not just an editor — it’s an extensible platform for crafting
highly personalized development environments. With tools like company ,
 yasnippet, lsp-mode and dap-mode , Emacs transforms into a feature-rich
Python IDE capable of competing with PyCharm or VS Code. 
 This guide explores how to evolve Emacs into a…
These are notable or amusing bugs and patches in public projects I dealt with in the past.
Introduction # 
 
 In my setup, some workstations run macOS. Recently, I encountered a
task I hadn’t faced before on macOS — scheduling recurring tasks. This
note outlines the recommended approach and provides a basic
introduction and step-by-step guide for achieving this, leaving the
rest for you to explore further on your own. 
 This note is by no means a…
Current Work # 
 
 I work at airSlate 
, where we build a platform for automating business workflows — creating, filling out, and signing documents in real time, without any code. The kind of thing that quietly replaces a lot of manual back-and-forth in companies. 
 Outside of work, I spend a good chunk of my time on Sortie 
 — an open-source orchestrator that dispatches coding…
This story started when I connected a fresh domain to Fastmail. I wasn’t expecting any issues at first — after all, it was just email, right? But things didn’t quite go as planned. Let me walk you through why I turned to AI for a solution. 
 Fastmail Email Setup: My Experience # 
 
 I hooked up a brand-new domain to Fastmail, one I’d just bought
from GoDaddy specifically for email…
Every Python program runs inside a boundary. On one side sits the
interpreter — dynamic, reflective, garbage-collected. On the other
side sits the operating system, the CPU, and libraries compiled to
native machine code. The Foreign Function Interface is the gate
between these two worlds. Understanding how that gate works, what it
costs to pass through, and which tools build…
There is a set of standard HTTP headers that every website should
implement to ensure a basic level of security. In this note, I’ll
cover these headers and how to set them up for sites deployed on
Netlify. 
 Common Security Headers # 
 
 First, let’s review the basic HTTP headers — these are general for all
requests and provide a foundational layer of security. 
…
In this post, I’ll tackle a straightforward problem: launching a
Celery task X after all tasks Y have been completed. Task X needs to
take the result of all the tasks Y as an input. While it seems like a
brute-force solution would be to manually store each result of task Y,
it’s more interesting to achieve this using Celery without manual
database manipulations or extra code.…
I’ll admit, I don’t use GnuPG intensively. So when I need it, I find
myself rummaging through bookmarks, notes, and past command histories,
trying to remember how I did it last time. This recurring quest was
enough to nudge me into making a cheat sheet for GnuPG’s essential
commands. As I put it together, I decided to include not just the
things I personally need to remember…
Intro # 
 
 This article continues my exploration into formal grammars. If you haven’t read the first part 
 yet, I highly recommend you start there before diving into this one. Otherwise, some things might seem unclear or not fully explained. And if you spot any inaccuracies or feel I should add something interesting, feel free to let me know. 
 META II # 
 
 In…
Intro # 
 
 In this article, I’ll take you on a journey through grammars and the
overarching systems used to describe them, like BNF, EBNF, and
ABNF. Don’t expect pinpoint academic precision here — this is more of
an introductory read, designed to get you acquainted with the
essentials. 
 I wasn’t a firsthand witness to the events I’ll discuss, nor do I
claim…