AI · alternatives · 2026
24 alternatives to Shadow Testing for Decision/or Algorithms
Hi HN! I’m a founder at Nextmv (YC 20) [1] We’ve been building out optimization algorithm testing capabilities (acceptance tests, etc.) and just shipped our first pass at shadow testing [2, 3]. In our experience, tools like shadow testing save time and build confidence in decision models, but tools also take time to build and maintain. We’ve seen shadow testing tools in the machine learning and MLOps space [4], but not so much in the operations research community. A lot of folks here [5] seem experienced with optimization models and we’d love to have your feedback! What do you like? What…
Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Shadow Testing for Decision/or Algorithms launched in 2023; newer entries below may have overtaken it.
- 1
TensorZero▲307Hi HN! We're Gabriel & Viraj, and we're excited to open source TensorZero. To be a little cheeky, TensorZero is an open-source platform that helps LLM applications graduate from API wrappers into defensible AI products. 1. Integrate our model gateway 2. Send metrics or feedback 3. Unlock compounding improvements in quality, cost, and latency It enables a data & learning flywheel for LLMs by unifying: • Inference: one API for all LLMs, with <1ms P99 overhead • Observability: inference & feedback → your database • Optimization: better prompts, models, inference strategies • Experimentation:…
2025 · github.com · its alternatives →
- 2
Trails▲81Hey all, Justin here. I previously built Phind, the AI search engine for developers. One of the biggest problems we had there was figuring out what went wrong with bad searches. We had tons of searches per day, but less than 1% of users gave any explicit feedback. So we were either manually digging through searches or making general system improvements and hoping they helped. This problem gets harder with agents. Traces are longer and more complex. It takes more effort to review them, so I'm building a tool that lets you analyze LLM outputs directly to help developers of LLM apps and agents…
Jan 2026 · trails-red.vercel.app · its alternatives →
- 3
Spec27▲34Hi HN! We’re a team of ML validation specialists and we’ve been building /Spec27, a tool for testing whether AI agents still do their job safely and reliably as models, prompts, tools, and surrounding systems change. We started working on this because a lot of current LLM evaluation work seems aimed at scoring general model behavior, while many teams are deploying systems that have a specific mission to fulfill. Many of the tools also assume you have full access to the agent stack and traces so you can place SDKs and Gateways, but a lot of agents are being created on vendor platforms…
Apr 2026 · spec27.ai · its alternatives →
- 4

Spelltest framework simulates conversations between AI ‘synthetic users' in an environment to test and refine LLM-based applications. It ensures your app converse with utmost accuracy and relevance. Post-chat, Spelltest assesses responses, providing qualitative and quantitative feedback on performance. Suitable for both chat and completion modes. When to use: - After modifying your prompt. - When your LLM provider updates. - As a CI step for you repo. All feedback and collaborations appreciated!
2023 · github.com · its alternatives →
- 5
Argmin AI▲32Hey, HN community! We've built Argmin AI after shipping LLM features where the demo worked, then the bill and latency got unpredictable in production. Prompts expanded, context grew, retrieval got noisy, retries appeared, and agent workflows added loops. Argmin AI optimizes LLM-related expenses as a system: 1. prompt and context efficiency 2. model selection and routing 3. RAG inefficiencies and caching opportunities 4. agent workflows (tool calls, retries, loop control) Changes are validated with evals and guardrails (tests, gates, judges), tailored to your quality definition and goals.…
Jul 2026 · argminai.com · its alternatives →
- 6PC
Hey HN — 2 months ago we shared our first product with the HN community (https://news.ycombinator.com/item?id=43362535). Despite receiving lots of traffic from HN, we didn’t see any traction or retention. One of our major takeaways was that our product was too complicated. So we’ve spent the last 2 months iterating towards a much more focused product that tries to do just one thing really well. Today, we’d like to share our second launch with HN. Our original idea was to help software engineers build high-quality LLM applications by integrating their domain knowledge into a…
2025 · withpi.ai · its alternatives →
- 7

Howdy friends. I've been a zero to one product manager for 12 plus years and along the way I kept borrowing pieces from different discovery frameworks until I had a methodology of my own, one that actually raises the odds of an idea succeeding. This does not replace user interviews obviously, but it leads you in the right direction. Looking forward for your feedback
Jul 2026 · github.com · its alternatives →
- 8IB
I built a tool to roast landing pages with AI agents. I was gathering feedback from watching landing page roast videos, and figured out I could prompt LLMs to analyse a screenshot and roast based on the same criteria. It's not 100% accurate yet, but it has been really insightful when I've tested it on my own websites. Let me know what you think!
2024 · roastmylandingpage.io · its alternatives →
- 9HP
Hi HN. I heard you like dev tools and AI, so we wanted to share our project that we’ve been working on. We’re working on Horizon [1] - a higher level abstraction for LLMs so that developers can spend less time trying to grapple with LLMs to make them work and more time with users. This is the starting feature set which takes an auto-ML approach to identify the optimal LLM model, hyperparameters, and prompt - instead of just giving you the tooling to figure it out yourself. You can read more about it in our documentations. Our view is that as LLMs become increasingly commoditized and prompts…
2023 · gethorizon.ai · its alternatives →
- 10PL
Hey HN, after years building some of the core AI and NLU systems in Google Search, we decided to leave and build outside. Our goal was to put the advanced ML and DS techniques we’ve been using in the hands of all software engineers, so that everyone can build AI and Search apps at the same level of performance and sophistication as the big labs. This was a hard technical challenge but we were very inspired by the MVC architecture for Web development. The intuition there was that when a data model changes, its view would get auto-updated. We built a similar architecture for AI. On one side is…
2025 · build.withpi.ai · its alternatives →
- 11
Mocked▲14Hi HN, I launched an AI tool a few months back to help with product management interviews. It's Leetcode-style prep, but you can verbally respond to questions and receive feedback. I originally started it as a side project, but it blew up on Linkedin and we're nearing 5-figure ARR. I would be grateful for some honest feedback and advice on both the growth and engineering side. I'm particularly interested in: - What's one feature you feel is glaringly missing? - How did similar educational consumer apps (7sage, Leetcode) scale beyond just ads? - Should I implement a landing page? I wanted to…
2025 · trymocked.com · its alternatives →
- 12ET
Hey Hacker News, For the last 2 months, I've been working on a testing agent to free developers from the endless maintenance of end-to-end tests. You just push up a PR, and our agent analyzes the code changes and automatically visits the preview to test things out like a real human! We also support describing tests in English (or even in the PR description), and we'll go through your site whenever you want via a GitHub action to test and make sure various core flows continue to work as expected. We are looking for early testers and are giving out a generous free tier! Just sign up on the…
2025 · playmatic.ai · its alternatives →
- 13

Hi guys, I’m excited to share an update on ReproModel, an open-source toolbox designed to streamline the testing and reproduction of machine learning models. I, like many of you, have really struggled with benchmarking and comparing models, from missing code, to opaque experiment parameters slowing the process. I decided to take matters into my own hands, and created a mini-toolbox in my free time to streamline the process. The goal is to reduce the time and effort spent on replicating experiments, enabling researchers to focus on innovation rather than setup. Knowing this task is not an…
2024 · github.com · its alternatives →
- 14IM
Hey HN! Thank you for all the support and feedback on my original submission 2 months ago. I've been improving the backend using a MCTS/AlphaZero approach and it's currently producing much better results. My long term goal is to allow users to manage multiple projects, deployed autonomously, both from scratch and by making continual updates all prompted with natural language. The cost of each project has been lowered to $9 as performance with smaller models has improved (I migrated from Claude-3-Opus to gemini-1.5-flash). Thanks for checking it out!
2024 · saas-quick.com · its alternatives →
- 15

- 16

I’ve spent the last 2.5 months building a product that runs LLM-powered code reviews on my pull requests — and I just launched it. The tool is built specifically for solo developers. You install it on your repo, trigger a scan by creating a pull request, and it leaves structured review comments using OpenAI under the hood. Funnily enough, I used the dev version of this app to review its own pull requests while building it. It helped me spot bugs, simplify structure, and keep quality high — all with minimal need for another human in the loop. Things I want to try out in the next months : -…
2025 · codii.dev · its alternatives →
- 17

Hello everyone! I’m thrilled to announce the latest feature from Mutahunter.ai, the ultimate tool for finding and fixing weaknesses in your code. We’ve designed Mutahunter to leverage mutation testing powered by advanced LLMs, helping you uncover vulnerabilities and enhance your code quality effortlessly. Introducing our newest feature: Detailed Mutation Testing Reports! After running our mutation tests, Mutahunter now generates comprehensive reports that clearly summarize: • Vulnerable code gaps • Test case gaps These reports significantly reduce the cognitive load on developers by…
2024 · github.com · its alternatives →
- 18TS
Hello Hacker News community! I'm currently working in financial risk management within the banking sector, and I began my career as a Data Science specialist. For quite some time, my friend and I have been developing a small pet project just for fun. This tool has repeatedly helped us save time when testing various hypotheses and machine learning models. The core idea is to combine different scripts—created in various programming languages and virtual environments—within a minimalist graphical interface. Whether you're building models, running a local neural network, or sending requests to…
2024 · its alternatives →
- 19EM
Hey HN, Steven here from CodeIntegrity https://github.com/codeintegrity-ai/mutahunter We’re obsessed with automating software testing, specifically mutation testing, and have been frustrated with its slow adoption despite its proven success. I have a pretty different perspective on mutation testing and have shared my thoughts on its current state - https://www.jungsteven.com/blog/2024-07-03-past-present-future-mutation-testing Over the past few months, we’ve developed a new mutation testing tool that’s easy to use and compatible with any programming…
2024 · its alternatives →
- 20
PwnScan▲8For at least a few years (since before COVID), in my circle everbody wants an AI tool that finds vulnerabilities in binaries. I have my reservations about such a tool because of my perception that AI is overhyped, so I decided to build one myself to see how useful it could be (or not). I was actually kinda surprised how well it worked for my collection of binaries with known CVEs. It definitely has false positives and negatives, as any static analysis tool would, but I think its actually somewhat usable. I dont think the results are super actionable, but interesting nonetheless. I still…
2025 · pwnscan.com · its alternatives →
- 21GV
Hey HN, I just updated my project that compares some LLMs. It uses your prompt for all the models and runs at the same time. You can see the results being generated in real-time and decide what's the best for your use case. I'm open to any suggestions and feedback. Thanks!
2024 · geminivsgpt.com · its alternatives →
- 22IB
Hey HN, I've been working on something cool that I wanted to share with you all. It's called Viewpoint, an analytics tool for LLMs like OpenAI, Anthropic models, and Gemini. The idea came from the constant flood of new LLM models and the need to figure out which ones work best for my projects without breaking the bank. With viewpoint, I can track token usage, costs, latency(WIP), and traffic over time, making it easier to compare different models and see which ones perform best and save money. The tool works asynchronously, so it doesn't add any latency to your LLM requests, and you have…
2024 · viewpointhq.com · its alternatives →
- 23

Hey HN, I’m one of two people working on Hyperscreen AI, an AI that does mock technical interviews with you so you can pass more tech screens. I shut my YC startup down a year ago and had to look for a job afterward. Even though I had interned at and landed multiple FAANG offers out of college, I spent almost 6 months looking for a job after my company failed. I was fortunate enough to get technical screens due to my network, but I failed many of them because I didn’t have anybody to practice with. All of my friends either already had jobs and weren’t looking, or were still working on their…
2025 · hyperscreen.ai · its alternatives →
- 24
Promposer.AI▲10Recently I found myself spending too much time testing edge cases when building LLM agents. Re-running the same case over and over again really kills the vibe and takes the fun out of building. As Andrej Karpathy (and others) have said, it should really be called “context engineering” rather than prompt engineering. Writing instructions is the easy part. The hard part is providing the right context and tools while staying within context window limits. And evaluation is the slowest step. That’s the main purpose of Promposer: to handle evaluations for you, so you can focus on improving prompts…
2025 · promposer.ai · its alternatives →
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