● Category

Learning Path

27 essays

Aug 4, 2026

Graph Algorithms: The Backend Engineer's Guide to Connected Systems

Graph algorithms are fundamental to managing interconnected data in backend systems. This article explores their practical applications in dependency resolution, pathfinding, and network analysis, contrasting storage approaches and detailing production-grade performance considerations.

Youssef El Hejjioui·10 min
Jul 28, 2026

How to Read Flame Graphs: From Pprof to Production Debugging

Flame graphs visualize CPU usage and call stacks, making them indispensable for pinpointing performance bottlenecks. They show where your code spends its time, helping identify hot paths, I/O waits, and inefficient algorithms under production loads. This guide covers interpreting their visual structure, decoding common anti-patterns, and understanding their utility in real-world debugging scenarios.

Youssef El Hejjioui·12 min
Jul 20, 2026

Achieving Sub-Millisecond Latency & High Throughput in Trading Applications

Building trading applications with extremely low latency and high throughput requires a meticulous approach beyond typical enterprise development. This piece dives into hardware optimizations, kernel bypass techniques, specialized software architectures, efficient memory management, and careful language selection, while acknowledging the inherent impossibility of true "0ms" latency. It covers the trade-offs involved and common pitfalls, illustrated with real-world scenarios

Youssef El Hejjioui·5 min
Jul 10, 2026

Applied Mathematics: The Unsung Hero of Backend Engineering

Understanding how mathematics underpins robust system design, performance optimization, and reliable operations is crucial for backend and infrastructure engineers. This isn't about calculus exams, but about practical applications that prevent outages and scale systems.

Youssef El Hejjioui·5 min
Jul 9, 2026

Algorithms That Actually Matter When Your Backend Is Burning

Forget competitive programming. This deep dive covers the practical algorithms that fundamentally impact the scalability, reliability, and performance of distributed backend systems – from consistent hashing for caching to rate limiting and probabilistic data structures that keep services alive at 3 AM. It's about preventing pages, not solving puzzles.

Youssef El Hejjioui·9 min
Jul 7, 2026

Beyond Arrays: Mastering Binary Search for Complex Problems

Binary search isn't just for sorted arrays. This article delves into how to leverage its O(log N) power for complex backend problems like optimal resource allocation, performance tuning thresholds, and even debugging, focusing on real-world pitfalls and production scenarios.

Youssef El Hejjioui·5 min
Jul 6, 2026

Sliding Window Algorithm: Backend Systems & Production Realities

The sliding window algorithm is a technique for processing a contiguous subsegment of data or events over time, crucial for backend systems tackling problems like rate limiting, real-time analytics, and anomaly detection. This article dissects its mechanics, common implementations (sliding log vs. sliding counter), performance trade-offs, and critical production considerations.

Youssef El Hejjioui·10 min
Jul 2, 2026

When DNS Fails: Troubleshooting the Silent Killer of Distributed Systems

DNS resolution issues often manifest as intermittent application failures, slow responses, or complete outages. This article details common root causes, from misconfigured 'resolv.conf' and caching problems to upstream authoritative server woes, and provides a practical guide for debugging these elusive problems in real-world production environments, including containerized setups.

Youssef El Hejjioui·5 min
Jul 2, 2026

JVM Memory Tuning: Avoiding Production Heartbreak

JVM memory tuning isn't about magical flags; it's about understanding application behavior, garbage collection, and native memory. This guide covers heap configuration, GC algorithm selection, off-heap memory issues, and essential observability practices to keep your Java services stable under load, without resorting to black magic or cargo culting JVM arguments.

Youssef El Hejjioui·5 min
Jun 30, 2026

Docker in Production: What Senior Devs Actually Do

Deploying Docker in production environments requires a pragmatic approach that moves beyond basic tutorials. This article covers the essential considerations for senior engineers, from choosing robust orchestration and building secure, immutable images to managing persistent storage, configuring reliable networking, implementing comprehensive observability, and executing zero-downtime deployment strategies. We'll examine the realities of scaling Dockerized applications and the operational discipline required.

Youssef El Hejjioui·12 min
Jun 28, 2026

Prompt Engineering: Or, The Art of Yelling at a Black Box Until It Behaves

Let's be real about "prompt engineering." It's less engineering, more like trying to coax a non-deterministic black box with incantations you found on a forum. We've all been there, 3 AM, debugging a prompt that worked yesterday.

Youssef El Hejjioui·8 min
Jun 26, 2026

The Reluctant 'Handbook' to the Managed Configuration Processor (MCP)

After surviving another config cascade, someone asked for an MCP handbook. Fine. Here's a 'guide' to the Managed Configuration Processor: what it pretends to be, how to poke it, and why it'll still eat your weekend.

Youssef El Hejjioui·5 min
Jun 25, 2026

The Outbox Pattern: When 'Commit and Publish' Just Isn't Cutting It Anymore

We've all been there: a critical business event vanishing between a database commit and a message broker publish. The outbox pattern, born from distributed system pain, ensures your microservices don't lie about their state.

Youssef El Hejjioui·8 min
Jun 24, 2026

Understanding Backpressure in Apache Kafka

Late-night debrief on Kafka backpressure: why your producers block, consumers lag, and how production systems truly buckle under load. It's not in the tutorials, it's what keeps you up at 3 AM.

Youssef El Hejjioui·8 min
Jun 24, 2026

When The Domain Fights Back: Untangling Production With Bounded Contexts

Ever stared at a stack trace at 3 AM and realized your "customer" means five different things across the codebase? That's the messy reality DDD's core concepts try to tame. This isn't about fancy patterns; it's about not getting punched in the face by your own system.

Youssef El Hejjioui·9 min
Jun 23, 2026

UML: Because Sometimes You Need a Map When the Ship's on Fire

We've all been there: staring at logs at 3 AM, wondering why

Youssef El Hejjioui·8 min
Jun 23, 2026

When Your ORM Calls In Sick: Surviving Production With Raw SQL

Remember that 3 AM call? When the ORM folded, and the DBA was unreachable? Yeah. This is about what saves your ass then: raw SQL, from CRUD to the dark magic of indexes and window functions.

Youssef El Hejjioui·5 min
Jun 21, 2026

Git and GitHub: Surviving the Source Control Gauntlet (and Beyond)

Cut through the noise and the terror of Git. This isn't a 'five easy steps' tutorial. This is about what actually matters when you're waist-deep in a production incident, trying to understand why a 'simple' change blew everything up.

Youssef El Hejjioui·7 min
Jun 20, 2026

So, You Want a Distributed System? Bless Your Heart.

Let's be real about distributed systems. It's not a whiteboard exercise; it's a production battle. We'll talk about why we end up building these things, and why they relentlessly try to break our spirits at 3 AM.

Youssef El Hejjioui·5 min
Jun 20, 2026

When Your Threads Start Eating Your Server: Understanding Thread Pools Beyond The Hype

Another late night debugging a thrashing service? This is a debrief on why thread pools exist, when they actually save your ass in production, and the ugly truths you'll learn when you inevitably get them wrong.

Youssef El Hejjioui·9 min
Jun 19, 2026

Consistent Hashing: Avoiding the Great Distributed System Reset Button

Ever had your distributed cache spontaneously combust because you added a node? Or watched your sharded database rebalance into oblivion? That's where consistent hashing steps in, not as a magic bullet, but as the lesser evil for managing change in a chaotic world.

Youssef El Hejjioui·9 min
Jun 18, 2026

The Real Theories That Scale Your Skills (Not The Ones On LinkedIn)

Forget the whiteboard dogma and AI-generated architecture diagrams. Scaling isn't about knowing fancy academic theories; it's about understanding how systems actually break under pressure and what that 3 AM pager call truly means for your code.

Youssef El Hejjioui·5 min
Jun 16, 2026

PgBouncer: The Connection Wrangler You Didn't Know You Needed (Until Everything Exploded)

When your PostgreSQL instance is choking on connections at 3 AM, PgBouncer often rides in. This isn't a tutorial, it's a debrief on why it matters, where it hurts, and how not to shoot yourself in the foot with it.

Youssef El Hejjioui·12 min
Jun 15, 2026

Memory Management and Pointers: The Pain You Still Need To Know

We've all been there: staring at an OOM error or a random SIGSEGV at 3 AM, wondering why 'managed memory' betrayed us. This isn't about C++ tutorials; it's about the deep, lingering pain of memory and pointers, even in our 'safer' languages.

Youssef El Hejjioui·8 min
Jun 14, 2026

UML: The Late-Night Confessions of a Production Survivor

Let's talk about UML. Not the textbook ideal, but the messy reality after you've spent too many hours tracing an 'elegantly designed' system back to its broken roots. This is about what diagrams actually help, and which ones just add noise.

Youssef El Hejjioui·5 min
Jun 13, 2026

Design Patterns: Between the Myth and Reality

We've all been there: the allure of design patterns promising elegant solutions. But after a few 3 AM production calls, the reality hits. This is an honest look at how patterns turn from theoretical beauty into debugging nightmares.

Youssef El Hejjioui·6 min
Jun 13, 2026

Projects That Will Make You Hate Your Life (and Become a Better Developer)

Forget another todo app. The real lessons aren't found in tutorials, they're carved out of production incidents at 3 AM. This isn't about shiny new frameworks; it's about understanding the core rot underneath.

Youssef El Hejjioui·12 min