# rehber (blogs) — RSS Amplifier Recent posts from the 1 feeds in the RSS Amplifier directory that cover rehber. Page: Feed: --- ## [Source of truth is all you need](https://alperenkeles.com/posts/source-of-truth/) _2026-08-10 · Alperen Keles · Alperen Keles_ Coding agents are, well, surprisingly good . Maybe I'm telling on myself by this, but I sometimes learn by inspecting the way the agent leverages an API, or the way it solves a problem that I couldn't wrap my head around in the first place. As agents are able to do more things, do them reliably and tirelessly, the position of a software engineer is ever-increasingly questioned, what is… ## [Next Chapter!](https://alperenkeles.com/posts/next-chapter/) _2026-07-01 · Alperen Keles · Alperen Keles_ Two days ago, I've defended my 5 year, 5 chapter Ph.D. thesis. Today, I write about what's next, a spiritual 6th chapter! My dissertation, titled "Designing Effective Property-Based Testing Frameworks", comprises of the results of four research papers and projects I've worked on during my Ph.D. Two of these papers are about PBT libraries I have worked on, and two are about PBT… ## [Representation-Free Editing](https://alperenkeles.com/posts/representation-free-editing/) _2026-06-16 · Alperen Keles · Alperen Keles_ Representation is an overloaded term in computer science. Colloquially, the term representation represents a concrete object that is the reflection of an abstract object. The representation carries over the properties of the abstract object into a new domain that is presumably more convenient for a purpose the representer has in mind. We use arrays to represent collections of items, we use… ## [What is random generation?](https://alperenkeles.com/posts/what-is-random-generation/) _2026-05-10 · Alperen Keles · Alperen Keles_ I wanted to write this as a sequel to "What is a property?" where I would talk about how Property-Based Testing libraries generate random structures, don't worry, I'll still do that! But I realized that without talking about randomness in computers, the writing would be incomplete. So the first part of this article will go into a core problem that we consider "solved" in PBT, which is… ## [Have we won, what now?](https://alperenkeles.com/posts/have-we-won/) _2026-05-01 · Alperen Keles · Alperen Keles_ Will Wilson of Antithesis is a terrific public speaker, his latest keynote "We won, what now?" at the flagship Antithesis conference, BugBash 2026, was another great hit. There are some other nice accounts of the conference and Will's keynote from Alex Weisberg and Murat Demirbaş , so I won't go into a detailed description of all the talk, but rather take the key idea and mash it… ## [On The Simplicity of Humanness](https://alperenkeles.com/posts/on-the-simplicity-of-humanness/) _2026-04-13 · Alperen Keles · Alperen Keles_ Just yesterday, Bryan Cantrill published a short piece that touches something that I think most of us fundamentally understand, but don't have the words. The article is very short, titled "The peril of laziness lost" . I recommend you all read it. I plucked out one sentence for you: The problem is that LLMs inherently lack the virtue of laziness. The essence is, our laziness is the reason we… ## [What is a property?](https://alperenkeles.com/posts/what-is-a-property/) _2026-04-05 · Alperen Keles · Alperen Keles_ When talking about Property-Based Testing, we typically talk in very abstract terms. There are properties, which define the correctness; there are generators, which define the domain; the PBT framework gives us APIs for writing property-based tests that combine the properties with the generators to find bugs. It's all very nice and simple. A (surprisingly) large chunk of my time goes into… ## [Closing the verification loop: Observability-driven harnesses for building with agents](https://alperenkeles.com/posts/harness-first-agents/) _2026-03-09 · Alperen Keles · Alperen Keles_ This is a mirror entry of an article I co-authored published in Datadog AI Blog . AI agents can now produce software faster than any team can verify it. The bottleneck has moved from writing code to trusting what was written. We have seen this pattern before. Early programmers resisted compilers because they could write better assembly by hand. Often they were right. Compilers earned trust because… ## [Seeing types where others don't](https://alperenkeles.com/posts/seeing-types-where-others-dont/) _2026-03-06 · Alperen Keles · Alperen Keles_ This is a mirror entry for my article published in The Consensus . Welcome to a snapshot of my multi-year long journey of inferring types from jq programs in order to produce better, understandable errors messages. Programmers are peculiar people, they, actually we, develop odd affections to otherwise impersonal concepts, such as programming languages, such as types. I am guilty of this affection,… ## [Specifiability is the Leverage](https://alperenkeles.com/posts/specifiability-is-the-leverage/) _2026-02-24 · Alperen Keles · Alperen Keles_ Almost a year ago, I wrote my first ever blog post on AI-assisted programming, Verifiability is the Limit . The core idea was a push against the school of thought that AI-assisted programming would scale to an infinite productivity level, because someone had to verify that the outputs conform to the given specification, the prompt . I predicted that this had, and would, give rise to uneven levels… ## [Crypto Payments, No Custody (Sponsored)](https://crawlproof.com/a/R2txRvhvG0ly) _2026-02-23 · **Sponsored**_ Send crypto to merchant wallets via API with real-time updates and automatic fees. ## [The Mechanics of Autonomous Software Translation](https://alperenkeles.com/posts/autonomous-translations/) _2026-02-11 · Alperen Keles · Alperen Keles_ 2026 started with a boom of AI-assisted autonomous translations, on 14th of January, Cursor published their post on Scaling long-running autonomous coding in which they created translations of a browser, Java LSP, Windows emulator and Excel. This was followed by an Anthropic post on Building a C compiler with a team of parallel Claudes , which has only further fanned the flames of the hype. Both… ## [LLMs could be, but shouldn't be compilers](https://alperenkeles.com/posts/llms-could-be-but-shouldnt-be-compilers/) _2026-02-06 · Alperen Keles · Alperen Keles_ I’ve been going round and round in my mind about a particular discussion around LLMs: are they really similar to compilers? Are we headed toward a world where people don’t look at the underlying code for their programs? People have been making versions of this argument since Andrej Karpathy’s “English is the hottest new programming language.” Computer science has been advancing language design by… ## [Test, don't (just) verify](https://alperenkeles.com/posts/test-dont-verify/) _2025-12-22 · Alperen Keles · Alperen Keles_ AI is making formal verification go mainstream. AI-assisted mechnical proving companies are raising funds on billion dollar valuations , new people are trying proof assistants, overwhelmingly Lean, at unprecedented rates. Models achieve fascinating results in competitions previously considered to contain some of the hardest problems in the world, such as IMO, ICPC, Putnam; as well as open problems… ## [Formal Metotlar ve Kanıtlı Programlama Hakkında](https://alperenkeles.com/posts/kanitli-programlama/) _2025-12-18 · Alperen Keles · Alperen Keles_ Hatalar, günümüzde programlamanın ve yazılım mühendisliğinin ayrılmaz bir parçası. Yazdığımız programlarda hatalar olacağını, bu hataların kaçınılmaz olduğunu, bu kaçınılmazlığın değiştirilemez olduğunu kabul ediyoruz, programlama etrafındaki kültürü bu şekilde geliştirdik. Linux Kernel'ından kullandığımız tarayıcılara, tarayıcılarda ziyaret ettiğimiz web sitelerine, bu sitelerin mobil… ## [Temporal Shrinking](https://alperenkeles.com/posts/temporal-shrinking/) _2025-11-22 · Alperen Keles · Alperen Keles_ Random testing, in isolation, is a stupid idea. You take a program, which has a practically infinite amount of possible inputs, you randomly pick one of those infinite possibilities in the hopes of breaking the program, or some assertion about the program, and it actually works (discovers bug) in even the most naive form possible, which is essentially the following loop: while True : input =… ## [Verification is Not the Silver Bullet](https://alperenkeles.com/posts/verification-is-not-the-silver-bullet/) _2025-11-18 · Alperen Keles · Alperen Keles_ This post is a sequel to my thoughts on "What are the limits of LLMs" ( Verifiability is the Limit ) and "What are the domains I believe LLMs will shine at autonomously" ( Breaking Verifiable Abstractions ). As I see verifiability as part of the mainstream discussions more and more, I decided to break down on the limits of verifiability, focusing on how verification as a general principle… ## [Designing A Digital Restaurant](https://alperenkeles.com/posts/designing-a-restaurant/) _2025-10-10 · Alperen Keles · Alperen Keles_ I had the second system design interview of my career last week, the first one was 7 years ago, I was a junior at college, the question was boring, and I fumbled it quite bad. That just made me scared of system design interviews, so I was pretty nervous, little did I know, it was actually very fun, so I wanted to write about it. The question, roughly put, is as follows: You walk into a restaurant,… ## [How can we secure Package Managers?](https://alperenkeles.com/posts/package-managers/) _2025-09-18 · Alperen Keles · Alperen Keles_ Package managers, however prevalent, feel as if they are still infants in terms of security, considering the various supply chain attacks we have seen in the previous few years. The few solutions I see as a response are (1) securing the producers of the packages via account security practices such as multi-factor authentication, (2) advocating against using external packages for convenience by… ## [From Hand-Tuned Go to Self-Optimizing Code: Building BitsEvolve](https://alperenkeles.com/posts/self-optimizing-system/) _2025-09-18 · Alperen Keles · Alperen Keles_ This is a mirror entry of an article I co-authored published in Datadog Engineering Blog . At Datadog, cost-aware engineering is more than a principle; it’s a performance challenge at scale. We’ve published how we saved $17 million by rethinking our infrastructure, and we’ve built Cloud Cost Management to help customers do the same. But scaling deep, expert-level code optimization across a… ## [Programlama Dilleri Hakkında](https://alperenkeles.com/posts/programlama-dilleri-hakkinda/) _2025-09-04 · Alperen Keles · Alperen Keles_ Programlama dilleri, programcı ile bilgisayar arasındaki en temel iletişim kanalı. Yazdığımız programlar derleyiciler (compilers) ve yorumlayıcılar (interpreters) ile bilgisayarların onları çalıştırabileceği formlara dönüşüyor, sonrasında ise kullanıcılar yazdığımız programları kullanabilir hale geliyor. Her ne kadar günümüzün büyük bir kısmını bilgisayara istediklerimizi yaptırabilmek için… ## [Trade Smarter With IBKR (Sponsored)](https://crawlproof.com/a/pXfKWR5XTGYh) _2025-09-03 · **Sponsored**_ Join Interactive Brokers through a referral and access low-cost global trading. ## [Breaking Verifiable Abstractions](https://alperenkeles.com/posts/verifiable-abstractions/) _2025-08-31 · Alperen Keles · Alperen Keles_ Abstractions are one of the central ideas of computer science as well building and engineering complex systems in general. In essence, an abstraction is an interface over a system or process, somehow enhancing the mechanisms in which we interact with the underlying system. A famous example of abstraction is a programming language, which abstracts details of how the underlying machine executes the… ## [A Better Vocabulary for Testing](https://alperenkeles.com/posts/vocab-for-testing/) _2025-08-16 · Alperen Keles · Alperen Keles_ Contemporary vocabulary for talking about software testing has bothered me for a long time. The concept of a unit in unit test is not really defined, integration tests are integrating arbitrarily scoped modules, the concept of an E2E test makes sense, but it very much underspecifies the actually tested behavior as well as methods for testing it, are you using automated agents, human supervision,… ## [Bilgisayar Mühendisleri için Hafif\* Ekonomi](https://alperenkeles.com/posts/yazilim-ekonomisi/) _2025-08-09 · Alperen Keles · Alperen Keles_ Yazılım endüstrisi inanılmaz büyük, dağınık, neredeyse her endüstrinin içerisine kendisini anahtar bir oyuncu olarak yerleştirmiş bir endüstri. 2011 yılında A16Z'nin kurucularından Marc Andreessen "Why Software Is Eating The World" (Yazılım Dünyayı Neden Ele Geçiriyor) yazısında sırtını yazılıma dayayan Amazon, Netflix, Spotify gibi devlerin nasıl ortaya çıktığını ve büyüdüğünü benim… ## [Filling in the Missing Bits](https://alperenkeles.com/posts/the-missing-bits/) _2025-08-02 · Alperen Keles · Alperen Keles_ The world is full of gaps, missing opportunities, unfinished projects, and unfulfilled potential. We walk around every day complaining about the problems we see in the world. We don't like the height of a shelf, the color of a wall, the shape of a doorknob, the line at the DMV, the length of the traffic light, the taste of our morning coffee, the feed our our social media, on, and on, and on.… ## [Time Budget as a Software Constraint](https://alperenkeles.com/posts/budget/) _2025-08-01 · Alperen Keles · Alperen Keles_ Software performance is a contentious topic among programmers. On one hand, you'll see Jonathan Blow arguing programmers should spend their valuable time bikeshedding small details to cut down a few CPU instructions, and on the other you'll see people running an electron app that runs on a hypervisor that runs on a VM, claiming everything's just fine. Ultimately, a large portion of… ## [Verifiability is the Limit](https://alperenkeles.com/posts/verifiability-is-the-limit/) _2025-03-09 · Alperen Keles · Alperen Keles_ LLMs have created an enormous turmoil within the software engineering community within the past 5 years, much of it revolving around one central question, what is the future of our profession? A set of competing paradigms with various degrees of human intervention and control has emerged, on the one side agents with little to no humans in the loop, recently popularized “vibe coding” that… ## [Tip Sistemleri Hakkında](https://alperenkeles.com/posts/tip-sistemleri-hakkinda/) _2024-12-01 · Alperen Keles · Alperen Keles_ Tip sistemleri(type systems), programlama aktivitesinin temelinde yer almalarına rağmen gözümüzün önünden kaçan, programlama dillerinin özellikleri arasında çoğu zaman düşünmediğimiz, en az konuştuklarımızdan birisi. Bu yazıyı tip sistemlerinin günlük programlama pratiklerimizi nasıl yönlendirdiğini merkeze alarak yazmaya çalışacağım. Tip Sistemi Nedir? Her programlama dili, bazen dikkatli bir… ## [Printf Debuggers for Free](https://alperenkeles.com/posts/debuggers-for-free/) _2024-11-23 · Alperen Keles · Alperen Keles_ Software engineering has many ancient debates. OOP vs FP, dynamic types vs static types, printf debugging vs visual debuggers... I personally always found the last one very intriguing, because it feels like we shouldn't have to choose at all. Why isn't there a best-of-both-worlds solution that allows us to get the level of convenience and integration printf does, with the level of…