The 2026 Node.js London Collaboration Summit trip report is officially live! 🚀 We gathered 50+ contributors to discuss the biggest technical shifts coming to the runtime. Here’s what’s on the horizon: 🗓️ Versioning Change: Starting with v27, Node.js version numbers will align with the calendar year. 🌀 New Streams API: A more efficient, unified way to handle streams using modern async iterators. 💾 Node VFS: A proposal for a native Virtual File System (node:vfs) for better SEAs and testing. ⚖️ AI Governance: Evolving our processes to handle the rise of AI-generated code and security reports. Big thanks to Bloomberg for hosting! 🇬🇧 Check out the full recap and recordings here:

You're in an ML Engineer interview at Apple. The interviewer asks: "Two models are 88% accurate. - Model A is 89% confident. - Model B is 99% confident. Which one would you pick?" You: "Any would work since both have same accuracy." Interview over. Here's what you missed: Modern neural networks can be misleading. They are overconfident in their predictions. For instance, I saw an experiment that used the CIFAR-100 dataset to compare LeNet with ResNet. LeNet produced: - Accuracy = ~0.55 - Average confidence = ~0.54 ResNet produced: - Accuracy = ~0.7 - Average confidence = ~0.9 Despite being more accurate, the ResNet model is overconfident in its predictions. While the model thinks it's 90% confident in its predictions, in reality, it only turns out to be 70% accurate. Calibration solves this. A model is calibrated if the predicted probabilities align with the actual outcomes. For instance, say a model predicts an event with a 70% probability. Then, ideally, out of 100 such predictions, ~70 should result in the event. Handling this is important because the model will be used in decision-making. In fact, an overly confident that is not equally accurate model can be highly misleading. To exemplify, say a government hospital wants to conduct an expensive medical test on patients. To ensure that the govt. funding is used optimally, a reliable probability estimate can help the doctors make this decision. If the model isn't calibrated, it will produce overly confident predictions. Reliability Diagrams are a visual way to inspect how well the model is currently calibrated. More specifically, this diagram plots the expected sample accuracy as a function of the corresponding confidence value (softmax) output by the model. If the model is perfectly calibrated, then the diagram should look like the identity function. That said, it is often also useful to compute a scalar value that measures the amount of miscalibration, called expected calibration error (ECE). One way to approximate the expected calibration error shown above is by partitioning predictions into equally spaced bins and taking a weighted average of the bins’ accuracy/confidence difference. These are some common techniques to calibrate ML models: > For binary classification models: - Histogram binning - Isotonic regression - Platt scaling > For multiclass classification models: - Binning methods - Matrix and vector scaling 👉 If you care about probabilities and both models are operationally similar, which model would you prefer? ____ Find me → @_avichawla Every day, I share tutorials and insights on DS, ML, LLMs, and RAGs.

I have never been an FBI agent. Never conducted an investigation. Never worn a wire or served a warrant or spent a winter in a field office where the heating runs four hours behind the interrogation schedule. I was a congressional staffer. Then a political appointee. Then a different kind of political appointee. Then the Director of the Federal Bureau of Investigation, which is also a kind of political appointee, except the furniture is nicer and the jet is mine. I run the building. I would like to tell you about the jet. It seats fourteen. It costs sixty million dollars. The interior was refurbished during the Bush administration and the procurement file describes the upholstery as "heritage cognac." I know this because I requested the file. Not for oversight purposes. I wanted to know the name of the color so I could describe it at dinner. Heritage cognac. It smells like a law firm that has never lost. I spend a lot of time in that smell now. I think it is the smell of having arrived somewhere that was never meant for you, and noticing that nobody has asked you to leave. Washington to Philadelphia is a hundred and forty miles. Amtrak runs it for forty-nine dollars. I flew the Gulfstream on May 10th because Alexis wanted to see George Strait. The suite was thirty-five thousand. Maybe fifty. I don't track numbers below six figures. The flight crew stayed on past eleven. Overtime. Security too. Someone will calculate the cost per mile of flying a sixty-million-dollar aircraft to cover a distance shorter than most Uber rides. That someone will not be me. I was in the suite. The suite didn't have a calculator. It had George Strait. The Bureau told reporters Alexis was "an invited guest of the performers." Representatives for George Strait and Chris Stapleton did not confirm this. They were never going to. But the FBI said it, and under my leadership, when the FBI says something, that is the evidentiary standard. I run the building. The building said it. It's true. Her protection detail is where the budget gets interesting. Twenty-four-seven coverage. SWAT-certified agents. Field officers drawn from multiple Bureau offices nationwide. Two armored SUVs at minimum. Hair appointments. Musical appearances. A blowout in Nashville required four agents in a parking lot for ninety minutes. The annual cost is roughly one million dollars before overtime, vehicle maintenance, and incidentals. The Bureau cites "hundreds of credible violent death threats" as justification. One person has been arrested. His name is Alden Welch Ruml, twenty-six, from Massachusetts. He sent emails. He faces five years. One emailer. One million dollars a year. Four SWAT agents per errand. A quarter of a million dollars in federal protection per verified threat. For context: the average FBI field office spends less annually on its entire confidential human source program. Informants embedded inside drug cartels, counterterrorism cells, organized crime families — the people whose testimony sends other people to prison — cost the Bureau less to keep alive than it costs me to ensure my girlfriend arrives at a salon escorted by men trained to rappel from helicopters. One of my officials suggested we conduct a formal threat assessment. A review. The kind of paperwork the Bureau has generated for seventy years whenever a protection decision requires justification. He had been with the Bureau for nineteen years. He asked in the hallway, in front of staff. I berated him. Not quietly. He stopped asking. He stopped asking. That phrase is going to recur in this document. I want you to notice it each time. Now. Alexis Wilkins is a country singer. I should mention this. She has released eight singles and one EP titled *Grit*. She has zero chart appearances. Her most-streamed song has five hundred and two thousand lifetime plays on Spotify. Taylor Swift accumulates that figure in approximately eleven minutes. A full-time country music journalist at the industry's leading independent publication stated that he had never heard of Alexis Wilkins before I started dating her. She has no active tour. She has never headlined a festival. Rolling Stone cited a forty-eight percent increase in her streaming numbers after we became public, which the same journalist clarified was "a forty-eight percent increase from virtually nothing." This is the person for whom the FBI fields a million-dollar annual protective detail. I want you to hold those two facts together — the streaming numbers and the security budget — and understand that they do not represent a miscalculation. They represent a value system. Her protection is not proportional to the threat. Her protection is proportional to her proximity to me. That is the formula. Proximity to the Director equals resources from the Bureau. I have applied it consistently. I have applied it to everyone. Which brings me to the people who are no longer here. I have removed over fifty career officials since January. Twelve have filed suit. Marshall Yates — my Congressional liaison, formerly the director of something called the Election Integrity Network, which existed to challenge the 2020 results — personally called field offices to compile names. Everyone who worked a case involving the President. Six thousand names were requested by the White House. The acting director before me was asked who he voted for. When he started supporting the President. Whether the FBI had tried to "put the president in jail." He was told the President hasn't forgotten. Three hundred counterterrorism and counterintelligence agents have been reassigned to immigration enforcement. The unit monitoring Iran — Iran, which operates proxy militias across four countries and maintains an active assassination program targeting American officials on American soil — was gutted. Six federal prosecutors in the Eastern District of Virginia have resigned or been pushed out rather than participate in the prosecution of the previous FBI Director, James Comey, whose crime was investigating the President and whose punishment is being investigated by the institution the President gave me as a gift. I am prosecuting the last Director for doing his job. I am doing this from a fifty-thousand-dollar suite while a sixty-million-dollar aircraft idles on the tarmac outside. Nobody in the building finds this ironic. The ones who would have found it ironic are gone. They stopped asking. My Deputy Director is Dan Bongino. He has never worked a federal case. His career before this was conservative talk radio. He receives the President's Daily Brief every morning — CIA product, NSA intercepts, the full intelligence take of the United States government — and he obtained his SCI clearance after I waived his polygraph. The FBI's own guidelines state that polygraphs are a "preliminary employment requirement." My lawyers reclassified him as a Schedule C political appointee. Experts said that's not how the statute works. The experts are career officials. Career officials are the previous administration's furniture. I am redecorating. Nikole Rucker is my personal assistant. She arrived at the Bureau on January 20th without a security clearance of any kind. She was physically escorted into the Director's suite because the door requires a clearance she did not possess. By February she was in London, seated across from a Western allied intelligence service, notebook open, pen moving. She used to work for Stephen Miller. The White House says she does not share operational details with him. I am told this is technically accurate in the way that most technically accurate statements are technically accurate. The polygraphs are still running. Just not for my people. We administer them now to career staff. The questions have changed. We ask whether they've criticized me. Whether they've spoken to a reporter. Whether they've expressed doubt about the direction of the Bureau. The machine measures stress. Under my leadership, stress has been reclassified as disloyalty. Disloyalty as a security risk. A security risk as grounds for termination. Fifty people have traveled this chain. Twelve are suing. The rest stopped asking. I run the building. In February a New York Times reporter named Elizabeth Williamson published details about the protective detail. I opened a preliminary inquiry. Federal stalking charges. We searched our databases for her information. The Department of Justice reviewed the file, found no legal basis, and terminated the inquiry. Called it retaliation. The Times' executive editor called it "a blatant violation of Elizabeth's First Amendment rights." I do not retaliate. I respond to threats. A journalist publishing accurate reporting about my personal use of public resources is, by my definition, a threat to operational security. My definitions are the ones that govern inside this building. I wrote the organizational chart. There is a framed copy on my wall. It has one name at the top. The Atlantic published a separate story. Excessive drinking. Frequent absences. Staff forcing entry into my home because I could not be reached. I filed a two-hundred-and-fifty-million-dollar defamation lawsuit. At my budget hearing, Senator Van Hollen cited the allegations under oath. I told him the only person slinging margaritas on the taxpayer dollar was him — in El Salvador, with a convicted gang-banging rapist. Fox News subsequently noted that public records do not support either characterization. But the line worked. That is the difference between evidence and performance. I have always understood which one this building rewards. In 2023, before any of this, I said the following on national television: "Chris Wray doesn't need a government-funded G5 jet to go to vacation. Maybe we ground that plane." I meant every word. We should have grounded his plane. So mine wouldn't invite the comparison. I sell merchandise. "Fight with Kash." T-shirts, hats, a children's book. The profits go to a foundation I started. The brand benefits from my position as Director of the Federal Bureau of Investigation. This is not a conflict of interest. A conflict requires two competing interests. I have one interest. It has never been healthier. I told the Senate that the FBI cannot meet its mission with a five-hundred-million-dollar cut. I requested twelve billion. Two billion more than last year. In the same period I spent a million on my girlfriend's security detail, fifty thousand on a concert suite, flew a sixty-million-dollar aircraft to cover a distance shorter than most commutes, waived background checks for three political appointees with no law enforcement experience, reassigned three hundred counterterrorism agents to check green cards, gutted the unit tracking Iran's assassination program, and opened a federal investigation into a newspaper reporter for the crime of publishing a newspaper. I told Hannity: "We are going to protect not only me and my loved ones but every American that is threatened." I meant the first seven words. The rest was institutional boilerplate. The kind of thing you say when the camera is on and the sentence needs to land somewhere that sounds like it includes other people. I run the building. Now I want to tell you about the water. The week before the concert I went to Pearl Harbor. The USS Arizona. A VIP snorkel. Nine hundred sailors and Marines are entombed in that hull. They have been there since 1941. The oil still leaks. It rises to the surface in small dark rainbows that break apart when you swim through them. The water was warm. Very clear. I could see the outline of the ship's superstructure below me, the geometry of a vessel that sank with its crew inside, and I remember the water temperature was perfect and the sun was on my back and my detail was on the shore and nobody in the water asked me to justify my presence above nine hundred dead. Recreational swimming at the Arizona is prohibited. The National Park Service said they were not involved. The Navy could not identify who authorized the outing. The logistics were coordinated by military email. A former government diver spoke to reporters anonymously. He said the access was unusual. He said it raised safety and security concerns. He spoke anonymously, the article noted, "for fear of retribution." A man who dives for the government is afraid to describe, on the record, how I swim. That is the climate. That is the building I run. A nineteen-year veteran stopped asking. Fifty career officials stopped working here. Three hundred counterterrorism agents stopped tracking the people who want to kill Americans. Six prosecutors stopped prosecuting. A government diver stopped talking. A reporter found her name in a database. And the oil keeps leaking from the Arizona, eighty-four years after the hull settled, surfacing in thin iridescent films that nobody is assigned to monitor because I reassigned them. I have never been an FBI agent. I have never conducted a federal investigation. I have never built a case or flipped a witness or spent a night in a surveillance van waiting for someone dangerous to make a mistake. But I have flown a sixty-million-dollar jet to a George Strait concert. I have watched the show from a suite that cost more than most Americans earn in a year. I have swum above nine hundred dead sailors in water so clear I could see their ship. And I have ensured, through the systematic removal of everyone who might object, that no one in the building will tell you any of this is wrong. The oil surfaces. It always surfaces. It has for eighty-four years. I run the building. The building doesn't ask questions anymore.