simonwillison-net-0ovi9d.txt (13492B)
1 [1]Simon Willison’s Weblog 2 3 [2]Subscribe 4 Sponsored by: [3]WorkOS — Make your app Enterprise Ready with SSO, SCIM, RBAC, 5 and more. 6 7 Vibe coding and agentic engineering are getting closer than I’d like 8 9 6th May 2026 10 11 I recently talked with Joseph Ruscio about AI coding tools for Heavybit’s High 12 Leverage podcast: [4]Ep. #9, The AI Coding Paradigm Shift with Simon Willison. 13 Here are some of my highlights, including my disturbing realization that vibe 14 coding and agentic engineering have started to converge in my own work. 15 16 One thing I really enjoy about podcasts is that they sometimes push me to think 17 out loud in a way that exposes an idea I’ve not previously been able to put 18 into words. 19 20 Vibe coding and agentic engineering are starting to overlap [5]# 21 22 A few weeks after vibe coding was first coined I published [6]Not all 23 AI-assisted programming is vibe coding (but vibe coding rocks), where I firmly 24 staked out my belief that “vibe coding” is a very different beast from 25 responsible use of AI to write code, which I’ve since started to call [7] 26 agentic engineering. 27 28 When Joseph brought up the distinction between the two I had a sudden 29 realization that they’re not nearly as distinct for me as they used to be: 30 31 Weirdly though, those things have started to blur for me already, which is 32 quite upsetting. 33 34 I thought we had a very clear delineation where vibe coding is the thing 35 where you’re not looking at the code at all. You might not even know how to 36 program. You might be a non-programmer who asks for a thing, and gets a 37 thing, and if the thing works, then great! And if it doesn’t, you tell it 38 that it doesn’t work and cross your fingers. 39 40 But at no point are you really caring about the code quality or any of 41 those additional constraints. And my take on vibe coding was that it’s 42 fantastic, provided you understand when it can be used and when it can’t. 43 44 A personal tool for you, where if there’s a bug it hurts only you, go 45 ahead! 46 47 If you’re building software for other people, vibe coding is grossly 48 irresponsible because it’s other people’s information. Other people get 49 hurt by your stupid bugs. You need to have a higher level than that. 50 51 This contrasts with agentic engineering where you are a professional 52 software engineer. You understand security and maintainability and 53 operations and performance and so forth. You’re using these tools to the 54 highest of your own ability. I’m finding the scope of challenges I can take 55 on has gone up by a significant amount because I’ve got the support of 56 these tools. 57 58 But I’m still leaning on my 25 years of experience as a software engineer. 59 60 The goal is to build high quality production systems: if you’re building 61 lower quality stuff faster, I think that’s bad. I want to build higher 62 quality stuff faster. I want everything I’m building to be better in every 63 way than it was before. 64 65 The problem is that as the coding agents get more reliable, I’m not 66 reviewing every line of code that they write anymore, even for my 67 production level stuff. 68 69 I know full well that if you ask Claude Code to build a JSON API endpoint 70 that runs a SQL query and outputs the results as JSON, it’s just going to 71 do it right. It’s not going to mess that up. You have it add automated 72 tests, you have it add documentation, you know it’s going to be good. 73 74 But I’m not reviewing that code. And now I’ve got that feeling of guilt: if 75 I haven’t reviewed the code, is it really responsible for me to use this in 76 production? 77 78 The thing that really helps me is thinking back to when I’ve worked at 79 larger organizations where I’ve been an engineering manager. Other teams 80 are building software that my team depends on. 81 82 If another team hands over something and says, “hey, this is the image 83 resize service, here’s how to use it to resize your images”... I’m not 84 going to go and read every line of code that they wrote. 85 86 I’m going to look at their documentation and I’m going to use it to resize 87 some images. And then I’m going to start shipping my own features. And if I 88 start running into problems where the image resizer thing appears to have 89 bugs or the performance isn’t good, that’s when I might dig into their Git 90 repositories and see what’s going on. But for the most part I treat that as 91 a semi-black box that I don’t look at until I need to. 92 93 I’m starting to treat the agents in the same way. And it still feels 94 uncomfortable, because human beings are accountable for what they do. A 95 team can build a reputation. I can say “I trust that team over there. They 96 built good software in the past. They’re not going to build something 97 rubbish because that affects their professional reputations.” 98 99 Claude Code does not have a professional reputation! It can’t take 100 accountability for what it’s done. But it’s been proving itself anyway—time 101 and time again it’s churning out straightforward things and doing them 102 right in the style that I like. 103 104 There’s an element of [8]the normalization of deviance here—every time a model 105 turns out to have written the right code without me monitoring it closely 106 there’s a risk that I’ll trust it at the wrong moment in the future and get 107 burned. 108 109 The new challenge of evaluating software [9]# 110 111 It used to be if you found a GitHub repository with a hundred commits and a 112 good readme and automated tests and stuff, you could be pretty sure that 113 the person writing that had put a lot of care and attention into that 114 project. 115 116 And now I can knock out a git repository with a hundred commits and a 117 beautiful readme and comprehensive tests of every line of code in half an 118 hour! It looks identical to those projects that have had a great deal of 119 care and attention. Maybe it is as good as them. I don’t know. I can’t tell 120 from looking at it. Even for my own projects, I can’t tell. 121 122 So I realized what I value more than the quality of the tests and 123 documentation is that I want somebody to have used the thing. If you’ve got 124 a vibe coded thing which you have used every day for the past two weeks, 125 that’s much more valuable to me than something that you’ve just spat out 126 and hardly even exercised. 127 128 The bottlenecks have shifted [10]# 129 130 If you can go from producing 200 lines of code a day to 2,000 lines of code 131 a day, what else breaks? The entire software development lifecycle was, it 132 turns out, designed around the idea that it takes a day to produce a few 133 hundred lines of code. And now it doesn’t. 134 135 It’s not just the downstream stuff, it’s the upstream stuff as well. I saw 136 [11]a great talk by Jenny Wen, who’s the design leader at Anthropic, where 137 she said we have all of these design processes that are based around the 138 idea that you need to get the design right—because if you hand it off to 139 the engineers and they spend three months building the wrong thing, that’s 140 catastrophic. 141 142 There’s this whole very extensive design process that you put in place 143 because that design results in expensive work. But if it doesn’t take three 144 months to build, maybe the design process can be a whole lot riskier 145 because cost, if you get something wrong, has been reduced so much. 146 147 Why I’m still not afraid for my career [12]# 148 149 When I look at my conversations with the agents, it’s very clear to me that 150 this is moon language for the vast majority of human beings. 151 152 There are a whole bunch of reasons I’m not scared that my career as a 153 software engineer is over now that computers can write their own code, 154 partly because these things are amplifiers of existing experience. If you 155 know what you’re doing, you can run so much faster with them. [...] 156 157 I’m constantly reminded as I work with these tools how hard the thing that 158 we do is. Producing software is a ferociously difficult thing to do. And 159 you could give me all of the AI tools in the world and what we’re trying to 160 achieve here is still really difficult. [...] 161 162 Matthew Yglesias, who’s a political commentator, yesterday [13]tweeted, 163 “Five months in, I think I’ve decided that I don’t want to vibecode — I 164 want professionally managed software companies to use AI coding assistance 165 to make more/better/cheaper software products that they sell to me for 166 money.” And that feels about right to me. I can plumb my house if I watch 167 enough YouTube videos on plumbing. I would rather hire a plumber. 168 169 On the threat to SaaS providers of companies rolling their own solutions 170 instead: 171 172 I just realized it’s the thing I said earlier about how I only want to use 173 your side project if you’ve used it for a few weeks. The enterprise version 174 of that is I don’t want a CRM unless at least two other giant enterprises 175 have successfully used that CRM for six months. [...] You want solutions 176 that are proven to work before you take a risk on them. 177 178 Posted [14]6th May 2026 at 2:24 pm · Follow me on [15]Mastodon, [16]Bluesky, 179 [17]Twitter or [18]subscribe to my newsletter 180 181 More recent articles 182 183 • [19]Notes on the xAI/Anthropic data center deal - 7th May 2026 184 • [20]Live blog: Code w/ Claude 2026 - 6th May 2026 185 186 This is Vibe coding and agentic engineering are getting closer than I’d like by 187 Simon Willison, posted on [21]6th May 2026. 188 189 [22] ai 2016 [23] generative-ai 1785 [24] llms 1751 [25] podcast-appearances 39 190 [26] vibe-coding 90 [27] coding-agents 201 [28] agentic-engineering 50 191 192 Next: [29]Live blog: Code w/ Claude 2026 193 194 Previous: [30]LLM 0.32a0 is a major backwards-compatible refactor 195 196 Monthly briefing 197 198 Sponsor me for $10/month and get a curated email digest of the month's most 199 important LLM developments. 200 201 Pay me to send you less! 202 203 [31] Sponsor & subscribe 204 205 • [32]Disclosures 206 • [33]Colophon 207 • © 208 • [34]2002 209 • [35]2003 210 • [36]2004 211 • [37]2005 212 • [38]2006 213 • [39]2007 214 • [40]2008 215 • [41]2009 216 • [42]2010 217 • [43]2011 218 • [44]2012 219 • [45]2013 220 • [46]2014 221 • [47]2015 222 • [48]2016 223 • [49]2017 224 • [50]2018 225 • [51]2019 226 • [52]2020 227 • [53]2021 228 • [54]2022 229 • [55]2023 230 • [56]2024 231 • [57]2025 232 • [58]2026 233 • 234 235 236 References: 237 238 [1] https://simonwillison.net/ 239 [2] https://simonwillison.net/about/#subscribe 240 [3] https://fandf.co/4daZLgh 241 [4] https://www.heavybit.com/library/podcasts/high-leverage/ep-9-the-ai-coding-paradigm-shift-with-simon-willison 242 [5] https://simonwillison.net/2026/May/6/vibe-coding-and-agentic-engineering/#vibe-coding-and-agentic-engineering-are-starting-to-overlap 243 [6] https://simonwillison.net/2025/Mar/19/vibe-coding/ 244 [7] https://simonwillison.net/guides/agentic-engineering-patterns/what-is-agentic-engineering/ 245 [8] https://simonwillison.net/2025/Dec/10/normalization-of-deviance/ 246 [9] https://simonwillison.net/2026/May/6/vibe-coding-and-agentic-engineering/#the-new-challenge-of-evaluating-software 247 [10] https://simonwillison.net/2026/May/6/vibe-coding-and-agentic-engineering/#the-bottlenecks-have-shifted 248 [11] https://simonwillison.net/2026/Jan/24/dont-trust-the-process/ 249 [12] https://simonwillison.net/2026/May/6/vibe-coding-and-agentic-engineering/#why-i-m-still-not-afraid-for-my-career 250 [13] https://twitter.com/mattyglesias/status/2049105745132585161 251 [14] https://simonwillison.net/2026/May/6/ 252 [15] https://fedi.simonwillison.net/@simon 253 [16] https://bsky.app/profile/simonwillison.net 254 [17] https://twitter.com/simonw 255 [18] https://simonwillison.net/about/#subscribe 256 [19] https://simonwillison.net/2026/May/7/xai-anthropic/ 257 [20] https://simonwillison.net/2026/May/6/code-w-claude-2026/ 258 [21] https://simonwillison.net/2026/May/6/ 259 [22] https://simonwillison.net/tags/ai/ 260 [23] https://simonwillison.net/tags/generative-ai/ 261 [24] https://simonwillison.net/tags/llms/ 262 [25] https://simonwillison.net/tags/podcast-appearances/ 263 [26] https://simonwillison.net/tags/vibe-coding/ 264 [27] https://simonwillison.net/tags/coding-agents/ 265 [28] https://simonwillison.net/tags/agentic-engineering/ 266 [29] https://simonwillison.net/2026/May/6/code-w-claude-2026/ 267 [30] https://simonwillison.net/2026/Apr/29/llm/ 268 [31] https://github.com/sponsors/simonw/ 269 [32] https://simonwillison.net/about/#disclosures 270 [33] https://simonwillison.net/about/#about-site 271 [34] https://simonwillison.net/2002/ 272 [35] https://simonwillison.net/2003/ 273 [36] https://simonwillison.net/2004/ 274 [37] https://simonwillison.net/2005/ 275 [38] https://simonwillison.net/2006/ 276 [39] https://simonwillison.net/2007/ 277 [40] https://simonwillison.net/2008/ 278 [41] https://simonwillison.net/2009/ 279 [42] https://simonwillison.net/2010/ 280 [43] https://simonwillison.net/2011/ 281 [44] https://simonwillison.net/2012/ 282 [45] https://simonwillison.net/2013/ 283 [46] https://simonwillison.net/2014/ 284 [47] https://simonwillison.net/2015/ 285 [48] https://simonwillison.net/2016/ 286 [49] https://simonwillison.net/2017/ 287 [50] https://simonwillison.net/2018/ 288 [51] https://simonwillison.net/2019/ 289 [52] https://simonwillison.net/2020/ 290 [53] https://simonwillison.net/2021/ 291 [54] https://simonwillison.net/2022/ 292 [55] https://simonwillison.net/2023/ 293 [56] https://simonwillison.net/2024/ 294 [57] https://simonwillison.net/2025/ 295 [58] https://simonwillison.net/2026/