Ideas that
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Stories, ideas and oddities about data, software and systems.
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Apache Spark WTF???
Apache Spark WTF??? 🎪 The Spark 4 Freak Show 🤡
Welcome to the Spark 4 Freak Show — the only carnival where defaults bite, configs whisper from the walls, and the architecture finally…
Apache Spark WTF??? ✈️ Come Fly With Me🧑✈️
Welcome to the airport. Keep your boarding pass close and your schema assumptions closer. Spark 4 just opened a new terminal for JSON, XML…
Apache Spark WTF??? 📖 The Neverending Real-Time Story 🐉
Four data engineers sat around the campfire, wrapped in old cluster logs, whispering about the thing that had eaten their micro-batches.
Apache Spark WTF??? 🧟 We Will RocksDB You 🧠
A stateless stream is a highway: rows pass and vanish. Add groupBy() or Spark 4’s transformWithState(), and the road loops into Stateful…
Apache Spark WTF??? 📈 Nothing Breaks Like A Chart 📉
Data engineering at scale is a surrealist act: we manipulate variables that don’t exist yet across a cloud of invisible computers. But for…
Apache Spark WTF??? 😈 Vices & Virtues 😇
Welcome, brothers and sisters of the bit, to the cathedral of Spark Data Sources V2.
Apache Spark WTF??? ❤️ What You Need Is Log 🪵
Yesterday, all my troubles seemed so far away. Then Spark failed. Now it looks as though the logs are here to stay…
Apache Spark WTF??? 🤔Hey, Didn’t I Run This Query Yesterday? 🦫
It’s 6:00 AM, and you’re trapped in data purgatory again: debugging the same parent-child hierarchy, fueled by cold coffee, pizza cache…
Apache Spark WTF??? 🪄 The Magic Number 🔮
For years, Spark SQL crushed joins but choked on programming logic, forcing us into a messy maze of Python or Scala glue code.
Apache Spark WTF??? 🙏 Losing My Precision 🧮
Oh life, it’s bigger. It’s bigger than DoubleType.
Apache Spark WTF???🧑🌾Growing Onions 🧅
Spark was already a layered vegetable of questionable emotional stability — a chaotic mix of Python, JVM, and that one AnalysisException…
Apache Spark WTF???☠️ Serializer Killa 🔪
Welcome back to Apache Spark WTF???, the place where we poke Spark with a stick and ask why the JVM is sweating.
Apache Spark WTF??? 😎 Straight Outta Comparison ⚖️
They say comparison is the thief of joy. And so it is. Especially when the comparison involves two Spark DataFrames, no clearly identified…
Apache Spark WTF??? 🪦 Back From The Dead 💀
The screen is glowing. The Spark UI has not moved in ten minutes. You check the driver logs, and there it is — the dreaded obituary:
Apache Spark WTF??? 🧛 Buffers The Slayer 🦇
Every Spark project has a moment where innocence dies.
Apache Spark WTF??? 🤖 Prompting In The Name 🧠
A few days ago, Databricks introduced Genie Code, a new AI assistant designed to act like a very caffeinated data engineer living inside…
Apache Spark WTF??? ❤️ The Love Boat ⛵
Welcome aboard, dear passenger of the data seas, to The Love Boat: LakeSail Edition — where the breeze is columnar, the deck is…
Apache Spark WTF??? — 😒 Suspicious Minds 🙄
“Photon is the next generation engine on the Databricks Lakehouse Platform that provides extremely fast query performance at low cost.” —…
Apache Spark WTF??? — 😠 Don’t Be K-Mean 😡
“Divide et impera” — this phrase comes from the ancient Roman Empire and, not surprisingly, it’s still relevant today. Although nowadays…
Apache Spark WTF??? — 🥊 Scuffle With My Shuffle (Part II)😵
The first round was brutal: single-partition Gzip jabs, multi-gigabyte shuffle hooks, SortMerge uppercuts, and enough spill files to bury…
Apache Spark WTF??? 🥊 Scuffle With My Shuffle (Part I)🤕
🎙️ Ladies and gentlemen — and distributed‑systems nerds of all ages — welcome to the Spark Processing Arena.
Apache Spark WTF??? — 🪲 Debuggin’ 🦗
In the world of Big Data, our heap isn’t just memory — it’s a tectonic plate shifting under the weight of a million shuffle partitions…
Apache Spark WTF??? — 𓁈 Looks Like An Exception 𓅓
Most data engineers wander Spark like tourists in the Valley of the Kings — snap a photo, mumble a chant, and retreat before anything…
Apache Spark WTF??? — 🧊 Kubefusional 🕋
Kubernetes (K8s). The system that swallowed the world. And yet, after twelve years of wrestling Apache Spark, I’ve somehow avoided Spark…
Apache Spark WTF??? — 🪖 SQL Goes Hardcore 🧠
“I love the sight of hardcore SQL in the morning.” (adapted from “Hardcore” by Tim Dog)
Apache Spark WTF??? — 🥶 The Last Error 👻
🕯️ Chapter ️I: In Which I Journey into the Heart of the Parser
Apache Spark WTF??? — 💣 Nuthin’ But A “GC” Thang 💥
When an exhausted GC meets a flood of data, there’s no mercy. Imagine one janitor, one mop, and a tsunami of Java objects. He’s collectin’…
Apache Spark WTF??? — ⭐Written In PySpark ⭐
So you thought PySpark was just “Spark, but in Python”? Spoiler: it’s not. It’s more like a cosmic translator — your Python code gets…
Apache Spark WTF???🔥Heiss Wie Feuer (Hot As Fire)🔥
Summer is officially over! No more scorching days, no more tropical, sweat-soaked nights. What a summer that was — hot as fire, the kind…
Apache Spark WTF??? — Welcome To Hell! 👹🔥🤘
It started as a simple task — connect Spark to a kerberized Hive. But the moment you hit Enter, the ground cracks open beneath you…
Apache Spark WTF??? — I Love It When A Plan Comes Together (Part III)
Plans, plans, plans… I definitely love this topic! And, without a doubt, it’s one of the biggest headaches I’ve had while working with…
Apache Spark WTF??? — I Like It When A Plan Comes Together (Part II)
Welcome back to another thrilling installment of our three-part deep dive into Spark execution plans!
Apache Spark WTF??? — I Like It When A Plan Comes Together (Part I)
When I was a kid, I was fun of TV shows like the A-Team. No matter how crazy their situations got, their plans always came together —…
Apache Spark WTF??? — That Thing You Do! (Part II)
Here we go again! I warned you it wasn’t going to take long before the second part of this intrepid journey into the inner workings of…
Apache Spark WTF??? — That Thing You Do! (Part I)
Apache Spark is all about speed and scalability, and at the heart of that magic lies partitions. Spark splits your data into partitions —…
Apache Spark WTF??? — Living Without You
January 1, 2025. The first day of a new year always feels like a good time to look back and reflect, especially on what went down in the…
Apache Spark WTF??? — The PolaRS
I don’t like benchmarks. They’re intriguing, but I just … don’t. It is believed that over 70% of researchers fail to reproduce others’…
Apache Spark WTF??? — All I Have To Do Is Stream
As 2024 comes to a close, I’ve come to realize just how much I enjoy teaching — even if it’s just sharing the little I know. I may not be…
Apache Spark WTF??? — Padding, Padding Cool
At first glance, padding strings seems like one of the most trivial tasks in programming — mundane, even. It doesn’t appear to have much…
Apache Spark WTF??? — Stranded On Dates Rows
Are you a Spark Scala enthusiast or more of a Pythonic PySpark aficionado? Maybe you think Java is just some old-school language you don’t…
Apache Spark WTF??? — Spark (Broad)Cast A Spell On Me
Welcome back to uncovering some of Spark’s darkest and lesser-known secrets. In this episode, we’ll delve deep into a concerning issue…
Apache Spark WTF??? — The deadly filter
Filters are arguably among the most well-known and valuable operations that can be applied to data. Filters, along with optimization…
Bricking News
🥊One Shot, One Chance: Training Databricks Genie for the CFO Fight🥊
This article is not about making Genie say “I don’t know” more often. I already wrote about that here.
We Made Genie Say “I Don’t Know” More Often And Usage Went Up
The first version of our Genie Space had a problem that looked like success: it answered almost everything. That’s exactly what made our…
Lakebase 🐘 All That She Wants 🧠
The fraud PoC was lightning-fast until we tried to make it helpful.
The Night Of The Living Lakebases
We enabled scale-to-zero for the Lakebase branch behind our fraud-investigation demo: a Databricks App where analysts inspect suspicious…
Databricks Summit 2026 🏛️ Hail The Emperor 🤴
Last week was Databricks Summit 2026, and Databricks came with a very clear message: AI is no longer just about building smarter models…
Databricks Summit 2026 👑 Salute The Queen 👸🏻
Back in 2014, data engineering was a simpler, more peaceful madness. Our infrastructure ran on vibes and a heavily traumatized cron job. If…
Databricks Lakeflow ✨ Spark This Way 🛣️
Custom Python script, we need to talk. You paginated APIs, swallowed broken CSVs, pretended timestamps were CDC, and failed heroically at 3…
Databricks 🤔 Are You Babysitting Me? 🍼
I picked a 16 GB Databricks node. The cluster metrics showed free memory, so I tried to give my Spark driver a little more heap. Databricks…
Agent Bricks 🌫️ Hazy Shade Of Beneficial💰
Somewhere in enterprise IT, five hundred AI agents just woke up, asked for OAuth, queried a Delta table, cited an HR policy PDF, and billed…
Synthetic Data Agent
🤖 SDA 06: Detecting Primary Keys, Foreign Keys, and Join Relationships
Profiling taught the Synthetic Data Agent how columns behave. Now it must learn that tables don’t exist in isolation.
🤖 SDA 05: Profiling Source Data — Distributions, Nulls, Formats, and Outliers
SDA 04 gave the Synthetic Data Agent a governed map of the data estate. It can see tables, columns, types, tags, comments, and declared…
🤖 SDA 04: Reading Unity Catalog Metadata — The Agent’s First Tool
In the previous article, we gave the Synthetic Data Agent something every serious data project eventually needs: a proper home.
🤖 SDA 03: Bootstrapping with Declarative Automation Bundles
After a short one-month pause, the Synthetic Data Agent is back.
🤖 SDA 02: Designing the Synthetic Data Agent
In the last article, we committed to building a Synthetic Data Agent on Databricks: one that inspects real governed data and generates…
🤖 SDA 01: Why Build a Synthetic Data Agent on Databricks?
I’m starting a personal project to build a practical synthetic data agent on Databricks.
Fraud Graph Arena
Greased Reyden: The Data Highway Escape
A mischievous ride through silos, legacy ETL, NULLs and wildly confident AI agents.
🕵️ FGA 02: Typewriter of the Living Dead 🐶
Designing the investigation board without letting the artwork become the application
🕵️ FGA 01: It’s Alive, but It Does Nothing 🐶
Building the Academy walking skeleton before the real suspects arrive
️🕵️FGA 00: The Game Starts Here🐶
Securing the crime scene before the first clue appears