Top all-time · #7048
Timefold
Company blog · timefold.ai/blog · on HN as cchianelprogrammingbusiness
Timefold is the company blog at timefold.ai, writing about programming and business. Since 2023, 11 different Hacker News readers have linked it 26 times, most often “OptaPlanner, the open source solver AI, forked as Timefold by its own creator”. No feed was found, so read it on the site itself.
Too few sampled comments (8) to say how often HN recommends it.?
Why HN links it
Timefold's site covers its open-source scheduling and constraint solver, a fork of OptaPlanner, with docs, examples and a fork announcement. Commenters link these pages without judging the writing.
Summarised by Claude from a sample of 8 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Pick a proven scheduling API or describe your problem and get a custom one. Field service, shifts, pickup and delivery, tasks. Deterministic, explainable.
Most-linked posts?
- OptaPlanner, the open source solver AI, forked as Timefold by its own creator3 people · 4 mentions · first linked 2023-05-02
- Java versus Python performance benchmarks on PlanningAI models2 people · 5 mentions · first linked 2025-02-04
- I built an AI company to save my open source project2 people · 2 mentions · first linked 2025-02-10
- /2 people · 2 mentions · first linked 2023-06-01
- /open-source-solver2 people · 2 mentions · first linked 2025-02-14
- How much faster is Java 21?2 people · 2 mentions · first linked 2023-08-25
What Hacker News says?
As someone who did a CPython Bytecode → Java bytecode translator ( https://timefold.ai/blog/java-vs-python-speed ), I strongly recommend against the CPython Bytecode → PySM Assembly step: - CPython Bytecode is far from stable; it changes every version, sometimes changing the behaviour of existing bytecodes. As a result, you are pinned to a specific version of Python unless you make multiple translators. - CPython By…
Comment linking /blog/java-vs-python-speed
on “Show HN: I built a hardware processor that runs Python”Submitted I built an AI company to save my open source project as a story · 451 points
HN discussionThose examples are available in Java, Python and Kotlin. We also have an overview of our open source solver here: https://timefold.ai/open-source-solver
Comment linking /open-source-solver
on “I built an AI company to save my open source project”Submitted I built an AI company to save my open source project as a story · 14 points
HN discussionAre the commercial offerings you mentioned better than TimeFold? [0] (formerly known as OptaPlanner before the main developers forked it) TimeFold's heuristics-based approach makes fast solutions to even highly-complex scenarios within the reach of anyone who can write Java or Python expressions that evaluate to true when constraints are satisfied. [0] https://timefold.ai/
Comment linking /
on “Planner programming blows my mind”Submitted How fast is Java 22? as a story · 5 points
HN discussionThere is also the Timfold project [1], which continues OptaPlanner and offers ongoing support and further innovation [2]. You can find the documentation here [3] and some helpful examples here [4]. [1] - https://timefold.ai/ [2] - https://timefold.ai/blog/red-hat-optaplanner-end-of-life-not... [3] - https://docs.timefold.ai/timefold-solver/latest/quickstart/o... [4] - https://github.com/TimefoldAI/timefold-quickstar…
Comment linking /blog/red-hat-optaplanner-end-of-life-notice
on “Mathematical Optimization for Cargo Ships”Submitted Java versus Python performance benchmarks on PlanningAI models as a story · 3 points
HN discussionI had to deal with a lot of FFI to enable a Java Constraint Solver (Timefold) to call functions defined in CPython. In my experience, most of the performance problems from FFI come from using proxies to communicate between the host and foreign language. A direct FFI call using JNI or the new foreign interface is fast, and has roughly the same speed as calling a Java method directly. Alas, the CPython and Java garbag…
Comment linking /blog/java-vs-python-speed
on “Tiny JITs for a Faster FFI”Submitted OptaPlanner Continues as Timefold as a story · 3 points
HN discussionYes, you could do this and it's likely it'll turn out as rather nice and decently performant code. You would, however, most likely run into the problem of finding people to maintain it that are willing to learn. Most Prolog teaching material is quite abstract in the sense that it mainly teaches the language and its tricks, not so much applications, though there are of course a lot of FOSS and example applications to…
Comment linking /open-source-solver
on “C Plus Prolog”Submitted OptaPlanner, the open source solver AI, forked as Timefold by its own creator as a story · 3 points
HN discussionI had the misfortune of translating CPython bytecode to Java bytecode, and I do not wish that experience on anyone: - CPython's bytecode is extremely unstable. Not only do new opcodes are added/removed each release, the meaning of existing opcodes can change. For instance the meaning for the argument to JUMP_IF_FALSE_OR_POP changes depending on the CPython version; in CPython 3.10 and below, it is an absolute addres…
Comment linking /blog/java-vs-python-speed
on “Decorator JITs: Python as a DSL”Submitted How fast is Java 21? as a story · 2 points
HN discussionIf you want to give Timefold a try locally - it should about twice as fast, still the open source version - try our single Maven or Gradle command on your codebase: https://timefold.ai/upgrade-optaplanner-to-timefold If you're interested in writing a blog around your Wedding Seating Planner (it looks very cool!), ping me on LinkedIn and we'll happily push it on our socials.
Comment linking /upgrade-optaplanner-to-timefold
on “Show HN: Better Seater – Wedding seating chart optimizer”Submitted Recommended Fit API helps amending schedules in case of unforeseen changes as a story · 1 points
HN discussionAgreed; another useful technique is "Feed it to a heuristic solver". Heuristic solvers tend to be easier to program and reason about than a SAT solver, since you can use your existing domain model. Moreover, your scoring function look like a typical function that can call third party libraries (as heuristic solvers see the function as a black box usually). Heuristic solvers beat SAT solvers in cases like VRP, wherea…
Comment linking /solver
on “Solving a corn puzzle with CP-SAT”Submitted Why the OptaPlanner team continues as Timefold - Timefold's first newsletter as a story · 1 points
HN discussionOptaPlanner was forked as Timefold by the team behind it: https://timefold.ai/blog/2023/optaplanner-fork/ We made it twice as fast (by replacing Drools).
Comment linking /blog/2023/optaplanner-fork/
on “MiniZinc”Submitted How much faster is Java 21? as a story · 1 points
HN discussionA good chunk of the day-to-day work of "operations research" consulting shops is scheduling. There is also dedicated software like Timefold, formerly RedHat OptaPlanner [0]. [0] https://timefold.ai/blog/optaplanner-fork
Comment linking /blog/optaplanner-fork
on “Ask HN: Anyone interested in improving scheduling?”Submitted How much faster is Java 21? as a story · 1 points
HN discussionCurrently, no language ports of Timefold Solver are planned. Unfortunately, FFI (foreign function interface) have a terrible performance penalty, and since we would be doing multiple FFI calls for moves, it can easily become 100x slower just from FFI overhead. This basically means you have two choices: 1. Translate the constraints from the new language to Java bytecode at runtime. 2. Translate the entire solver to a…
Comment linking /blog/java-vs-python-speed
on “Using OR-Tools CP-SAT for Scheduling Problems”Submitted Scheduling solver OptaPlanner forked as creator leaves RedHat to found startup as a story · 1 points
HN discussionTo the author: what is the algorithmic approach to determine a schedule? Once you add a couple of constraints or complications (e.g. can't be on-call two nights in a row, or on-call weekends count 1.5x because they are more "painful"), it quickly becomes a fairly general constraint satisfaction problem. This is a field with deep mathematics involved and decades of academic literature. As far as I know, reaching the…
Comment linking /
on “Is the scheduling of oncall work something worth making better?”
