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Reposted by Dominik Tornow

Hillel @hillelwayne.com · 29/07/2026

I am delighted to announce that after 5 years of work, 15 early releases, 50,000 words written, and 100,000 more deleted, *Logic for Programmers* is now complete and available in print! Blog post announcement: www.hillelwayne.com/post/lfp/ Website: logicforprogrammers.com

logicforprogrammers.com

Logic for Programmers

Practical math for the working programmer.

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Reposted by Dominik Tornow

ScyllaDB @scylladb.com · 10/07/2026

@dominiktornow.bsky.social always brings highly technical insights to our conferences. Join Dominik at @P99CONF to learn how a closed loop guided an agent from prompt to a production-grade implementation of @resonatehqio.bsky.social on ScyllaDB. www.p99conf.io?latest_sfdc_... #ScyllaDB #P99CONF

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Dominik Tornow @dominiktornow.bsky.social · 11/02/2026

Systems engineering rests on accurate and concise mental models. Libraries, frameworks, or platforms come and go, but principles are forever Join me at Monster Scale Summit

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Dominik Tornow @dominiktornow.bsky.social · 29/01/2026

Quint is the specification language you've been looking for quint-lang.org

quint-lang.org

Quint

Executable specs for reliable systems

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Dominik Tornow @dominiktornow.bsky.social · 25/01/2026

I am wondering if Claude Code excels if a specification includes exhaustive pre and post conditions. Without stating how to implement a function, we can still rigorously specify what the function does (example in Dafny)

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Dominik Tornow @dominiktornow.bsky.social · 11/01/2026

My current mental model of coding with agents: Human attention moves to the edges

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Dominik Tornow @dominiktornow.bsky.social · 10/01/2026

This diagram captures the core thesis of A Note on Distributed Computing: Distributed and non-distributed executions are fundamentally different beasts Distribution fragments execution

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Dominik Tornow @dominiktornow.bsky.social · 10/01/2026

Distributed System ≠ Distributed Execution A distributed system is a collection of concurrent components that communicate by exchanging messages A distributed execution is an execution that is distributed across those components The dist sys is the stage for the dist exe

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Dominik Tornow @dominiktornow.bsky.social · 01/01/2026

My advice for software engineers in 2026 Get into formal methods Not to prove your system correct but to prove your thinking correct

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Dominik Tornow @dominiktornow.bsky.social · 31/12/2025

One more condition (j < i + k) gives us bounded idempotence. Think Kafka retention: a request is idempotent only as long as the system remembers the request

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Dominik Tornow @dominiktornow.bsky.social · 30/12/2025

Systems don't pause between retries If action a was applied at step i, then replaying a at any future step j is a no-op Idempotence is a property of traces

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Dominik Tornow @dominiktornow.bsky.social · 30/12/2025

The mathematical definition of idempotence will fail you in production Not this Applying a request n times has no effect beyond the first application But that Applying a request n times, regardless of how the state has evolved in between applications, has no effect beyond the first application

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Dominik Tornow @dominiktornow.bsky.social · 28/12/2025

Fun with Types: The Shape of Durable Executions Haskell's type system is a great vehicle for formalizing @resonatehqio.bsky.social 's core execution model, execute_until_blocked The shape of the conversation between User Program, Worker, and Server just fell out of the type system

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Dominik Tornow @dominiktornow.bsky.social · 22/12/2025

Property-based Testing and Deterministic Simulation Testing change how you think about invariants: First you defend the invariants your system has. Then you design the invariants your system should have Invariants become aspirational, not just defensive

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Dominik Tornow @dominiktornow.bsky.social · 21/12/2025

Event-driven. One of the most used terms in software engineering but with no formal definition I've looked. I've found nothing Please drop papers

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Dominik Tornow @dominiktornow.bsky.social · 18/12/2025

Vibe coding forces the question: Where do guarantees come from?! Platform Property P is certain. All valid programs have P Think memory-safe Rust program Application Property P is possible. Some valid programs have P Think memory-safe C program

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Dominik Tornow @dominiktornow.bsky.social · 14/12/2025

Deterministic Simulation Testing turns vibe coding into verified coding LLMs are great at writing code, but just like their human counterparts, they miss edge cases DST doesn't DST is the fitness function your coding agent needs to maximize

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Dominik Tornow @dominiktornow.bsky.social · 12/12/2025

The @resonatehqio.bsky.social server is responsible for • Coordination (incl scheduling) • Supervision (incl recovery) That is, the server is responsible for scheduling a distributed execution onto a distributed system and reschedule parts of the execution when parts of the system fail

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Dominik Tornow @dominiktornow.bsky.social · 03/12/2025

Durable Executions, defined A crash? An interruption. A sleep? An interruption. Same suspension. Same resumption. Same solution. The full definition: 12 words. The minimal implementation: 50 lines. journal.resonatehq.io/p/durable-ex...

journal.resonatehq.io

Durable Executions, defined

Suspend anytime, resume anywhere

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Dominik Tornow @dominiktornow.bsky.social · 03/12/2025

Durable Executions, defined Every durable execution framework: write normal code, get fault tolerance. Yet nobody defines what normal code or fault tolerance are The alternative: a rigorous definition, grounded in first principles, and a minimal implementation Dropping today

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Dominik Tornow @dominiktornow.bsky.social · 02/12/2025

In distributed systems, you can never know "what is", you can only know "what was" Even in consensus, you never know the current value, you only know the value at an offset in the log Every decision is made on a stale understanding of the world

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Dominik Tornow @dominiktornow.bsky.social · 01/12/2025

Resonate's Distributed Async Await doesn't add events, event types, event logs, or complex replay machinery. Resonate makes promises durable. That's it.

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Dominik Tornow @dominiktornow.bsky.social · 01/12/2025

Distributed Async Await, @resonatehqio.bsky.social Durable Executions framework, rests on one mechanic: skip-when-done - Checkpoint before the function starts - Checkpoint after the function returns - On restart, skip what's done Everything else follows from there Dead simple

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Dominik Tornow @dominiktornow.bsky.social · 28/11/2025

Join Matklad and me in Lisbon next week for an evening of systems engineering with @tigerbeetle.com and @resonatehqio.bsky.social I will talk about Write Last, Read First: How to keep systems consistent without transactions bsky.app/profile/tige...

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Dominik Tornow @dominiktornow.bsky.social · 26/11/2025

Dijkstra argued against unconstrained goto, not goto itself: The unbridled use of goto statements makes it terribly hard to find a meaningful set of coordinates in which to describe the process progress Unconstrained Event-Driven Architecture is distributed goto

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Dominik Tornow @dominiktornow.bsky.social · 25/11/2025

Today's GoTo is Event-Driven Architecture (Read first. Yell later)

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Dominik Tornow @dominiktornow.bsky.social · 24/11/2025

Why your code should crash more Assertions seem extreme: they don't throw exceptions, they crash the process. Yet continuing after a violation is worse than crashing. Shut it down. Enable assertions in production dtornow.substack.com/p/assert-in-...

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Reposted by Dominik Tornow

Gunnar Morling @gunnarmorling.dev · 20/11/2025

📝 Blogged: "Building a Durable Execution Engine With SQLite" Exploring the fundamentals of DE, based on a minimal engine built from scratch, using #SQLite as an execution log, and modern #Java (👋 virtual threads). 👉https://www.morling.dev/blog/building-durable-execution-engine-with-sqlite/

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Dominik Tornow @dominiktornow.bsky.social · 16/11/2025

The Distributed Async Await protocol builds on two (abstract) primitives: Execute until Blocked Make progress by taking one incremental step Send Communicate by sending one message Enabling any durability model on any transport

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Dominik Tornow @dominiktornow.bsky.social · 15/11/2025

When durable and ephemeral timelines collide What happens when your agent crashes while the LLM is streaming tokens to the user?! Chapter 4: Lifetime Management in Agentic Systems

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Dominik Tornow @dominiktornow.bsky.social · 12/11/2025

Mastering Continuations = Mastering Control Flow A good starting point to understand continuations and programming with continuations is Control structures in programming languages: from goto to algebraic effects by Xavier Leroy

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Dominik Tornow @dominiktornow.bsky.social · 12/11/2025

Orchestration vs Choreography Forget the clumsy analogies Orchestration The platform manages the continuation Choreography The application manages the continuation Everything else is noise

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Reposted by Dominik Tornow

TigerBeetle @tigerbeetle.com · 06/11/2025

The Write Last, Read First Rule How to guarantee strict serializability across database systems A special guest post from @dominiktornow.bsky.social tigerbeetle.com/blog/2025-11...

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Dominik Tornow @dominiktornow.bsky.social · 05/11/2025

Partial Failure & Partial Retry RPCs create recovery boundaries: When an execution crashes, only the executions within its recovery boundaries restart Executions in different recovery boundaries (across RPCs) continue running.

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Dominik Tornow @dominiktornow.bsky.social · 05/11/2025

Partial Failure but Total Retry?! If we follow the familiar model of chained HTTP calls then a failure in the chain forces a restart from the failure point This works for short-lived, cheap executions, but collapses under long-lived, expensive ones

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Dominik Tornow @dominiktornow.bsky.social · 03/11/2025

From the terminal to the cloud, from prototype to production Learn how agents scale beyond a single machine and master identity, coordination, and recovery Build a recursive, distributed Deep Research Agent with @resonatehqio.bsky.social + OpenAI—in under 120 lines Chapter 3 is live

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Dominik Tornow @dominiktornow.bsky.social · 02/11/2025

A Promise doesn’t just represent eventual completion A Promise also represents eventual invocation We just tend to forget the latter

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Dominik Tornow @dominiktornow.bsky.social · 01/11/2025

I'm experimenting with animations for the 3rd chapter of Systems Engineering for Agentic Applications This shows the call graph of the recursive, distributed Research Agent unfolding over time, highlighting durable promises I dig the result but they are a lot of work 🥲

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Dominik Tornow @dominiktornow.bsky.social · 01/11/2025

Weekend Treat ... sorry ... Read 🎃 Formal models are magic. Not only as a verification tool but as a thinking tool, lifting the fog of uncertainty and assumption Their magic lies in rigorous, ruthless, relentless clarity

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Dominik Tornow @dominiktornow.bsky.social · 30/10/2025

Two sentences explain I/O better than any CS course If an expression yields an effect, it percolates through the program to the top, with the context stored as a continuation. An external authority handles the effect and passes the result back to the continuation.

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Dominik Tornow @dominiktornow.bsky.social · 24/10/2025

Uncertainty, formalized: Possible Worlds The fewer worlds an agent considers possible, the less his uncertainty, and the more he knows In Reasoning about Knowledge

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Dominik Tornow @dominiktornow.bsky.social · 23/10/2025

Trampolined Style If you want to understand Event Loops, you need to read this paper from 1999: A trampolined program is organized as a single loop in which computations are scheduled and allowed to proceed in discrete steps. Grokking Event Loops = Grokking Continuations

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Dominik Tornow @dominiktornow.bsky.social · 22/10/2025

Join me in 30 min. I'll be in the live chat

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Dominik Tornow @dominiktornow.bsky.social · 22/10/2025

Building a recursive, distributed Deep Research Agent, scaling to hundreds of agents across dozens of nodes Chapter 3 covers: ➡️ Agent Identity ➡️ Coordination ➡️ Recovery When agents leave the terminal, you need to become a distributed systems engineer

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Dominik Tornow @dominiktornow.bsky.social · 21/10/2025

Roll up your newspapers, we’re squashing Heisenbugs with Deterministic Simulation Testing 🗞️ Join my talk tomorrow 11/22, 11:20 AM PDT I'll be in the live chat for Q&A Sign up below ⬇️

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Dominik Tornow @dominiktornow.bsky.social · 20/10/2025

Run your app for minutes, hours, days, weeks, or month On FaaS like AWS Lambda or GCP Functions Serverless @resonatehqio.bsky.social

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Dominik Tornow @dominiktornow.bsky.social · 20/10/2025

Introducing Serverless @resonatehqio.bsky.social Build distributed, durable applications with Resonate's dead simple programming model, Distributed Asynchronous Await Now on serverless

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Dominik Tornow @dominiktornow.bsky.social · 14/10/2025

Did the dreaded Heisenbug infect your system?! Then don't miss my talk on Deterministic Simulation Testing See you next week

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