How do I actually work with Sonnet 5.5?

[u/AngelaTheRipper]

So some background. I'm a developer. Definitely still a bit of a noob with AI agents. Job pays for a Github Copilot subscription.

Anyways, I've been using Opus 5 and recently Opus 5.5, both on Medium, and it's been basically the best thing ever.

I give it a bug that I really only know the presentation and it'll find it and fix it and it's some edge case of an edge case over an intersection of like 3 separate flows due to like 2 lines of code that were written without the foresight that that part might intersect with something else, that nobody would ever find by hand. I can give it fairly general prompts on how I want something to change and it'll ask follow up questions and get it at least 90% right on first try. I've had it refactor entire process flows because one of the projects I'm on fell victim to a BA who's more concerned about making the velocity in Jira look good than making the UX not suck (which lead to some really clunky UI where each upload type is its own box and each email similarly had its own little button to trigger them and dozens of itty bitty tiny tickets). Luckily he's on paternity leave right now so me and our business contact who's been sitting ex-officio as the back-up BA have been up to some shenanigans. I've had it update an application that was originally written in probably like 2005 and has resisted multiple attempts at framework upgrades and fixing some really cursed solutions, and after spending probably way too many tokens it got it done. It will go digging through the codebase, figure out how something works, where the data comes from, and act accordingly. Overall solid 10/10 from me.

Enterprise has been complaining about high token usages and our "Principal Cloud Architect" who probably hasn't actually pushed any code in many many years has been writing passive-aggressive blog posts about how we're committing "anti-patterns" spending too many tokens, and should all be using Luna or MAI-Code-1.1-Flash and escalate to the medium models if they fail because they don't seem to understand that they're ahead if $40 of tokens shaves off probably a week of work. Manager has been asking why is my token spending so high and I always have things to point at as to where it went which is just met with "Ah, okay".

So anyways I tried Sonnet 5.5 (on medium) and it kinda just shit the bed. Gave it something simple "Wrap this in a alert-danger if the finding is X". First it wrapped the entire card, okay maybe I wasn't clear enough, my bad, was a really busy day. Then broke the wrapping completely (I think the conditional on it was broken). Then on the third try despite having access to both the front and backend code, and the user sitting in front of the computer who it could ask, it decided that the field is a boolean (nope, it's a string), and applied that so it highlighted on every single record because any non-empty string will evaluate to true in JS. At point of which I was like "Okay I tried, Opus, fix this", which it did.

So how do I actually work with Sonnet 5.5 because my first impression is that it's really lazy and incurious. Like dealing with a Genie or a temp with a bad attitude it decided that's the minimum it could get away with and it shot its shot and completely missed.

[u/OkLettuce338]

plan in opus and have it build you the tickets for sonnet to implement. Make sure it knows a sonnet agent will be implementing and tell it to scope the work accordingly. Then have it delegate those tickets. Works with haiku 5.5 too, btw. Obviously not all tasks, but many straightforwards tasks can be delegated.

The trade off is this takes more PRs and more time. But it's cheaper

[u/Yweain → u/OkLettuce338]

Is it cheaper? Sonnet is what, half the price of opus? In my experience it spends WAY MORE than twice the number of tokens to complete the task.

[u/OkLettuce338 → u/Yweain]

IME it ends up being a lot cheaper. Like 1/2 to 2/3 the cost

[u/InfiniteKraft → u/Yweain]

I only observed that if you use Sonnet Max. Try XHigh or High

[u/TimSylvester_]

Cutting edge agents (Fable) are for solving complex, genuinely hard problems, that inform planning documentation.

High-end agents (Opus) are for writing planning documentation that are used to write work plans.

Mid-range agents (Sonnet) are for turning planning documentation into well structured, well defined work plans that can be implemented with zero reasoning.

Low-end agents (Haiku) are for translating work plans into actual code.

[u/sheeproomer → u/TimSylvester_]

Yeah and if sum up how many tokens are using by these methods, I use Opus 5.5 high that does all of the above in one go and still costs me less tokens in time because there is no need in letting a bare agent reread its instructions every time, burning token

And to boor, the code quality is higher.

[u/nighpanda1024]

if you want to save some token, use opus to create a plan in plan mode then use sonnet to implement it

[u/unbannnned]

You work with sonnet on codebase by using opus 5.5 on ultra code instead

[u/InfiniteKraft]

I find Sonnet 5.5 High very good as implementer with Opus 5.5 High as a reviewer

[u/CorpT]

Actually start looking for another job.

[u/Another_Bit_1725]

Plan it using Opus, Let the coding part be handled by Sonnet 5.5

In the end Review the diff or it will automatically do it by opus which will cost so do it yourself instead of Opus. Thats it.

Use Graphify, Ponytail to navigate the codebase, and keep it simple yet optimal.

Thats it.

[u/Odd_Cut_7449]

I would not use Claude models on github copilot. Github Copilot is all about usage efficiency (you pay api prices).

Use Gpt-6.1 sol with gpt-6 Luna subagents (Low: discovery, summaries. Max: simple implementation)