The effect of generation tools on development work is being studied and is not yet settled.
Task shift
Less typing and more reviewing and specifying.
Which changes what the job consists of.
Measured productivity
Studies finding effects ranging from substantial to negligible.
Which depends heavily on context.
Code quality concerns
Research examining maintainability of generated code.
Team practices
Review processes adapting to higher volumes of generated code.
Why the evidence is so mixed
Studies differ in task type, developer experience, codebase familiarity, tool version and what was measured.
Which produces results ranging from large improvements to measurable slowdowns, all of them plausibly correct for their conditions.
Anyone citing a single figure for developer productivity improvement is extrapolating from a specific study to a general claim it does not support.
Where gains are clearest
Unfamiliar languages, boilerplate and well-specified isolated functions.
Which is real and useful.
Where they are least clear
Large existing codebases requiring context the model lacks.
Review culture
Teams adapting standards to generated code volumes.
Which is an organisational rather than technical change.
Skills
Specification and review becoming more central.
Why the mechanics are worth understanding
These systems are described in language that suggests understanding, reasoning and knowledge, and the underlying operations are considerably more specific than those words imply. That gap is where most confusion, most disappointment and a substantial amount of misplaced trust originates.
Someone who knows that a language model predicts tokens, that it has no separate lookup step, that its context is a hard limit and that its confidence is unrelated to its accuracy will make better decisions about when to use one than someone working from the marketing description.
The pattern across all of this
Nearly every behaviour that people find surprising follows directly from a design choice that is documented and comprehensible. Invented citations follow from the training objective. Difficulty with spelling follows from tokenisation. Degradation in long conversations follows from context limits. Cost structures follow from the fact that inference is not free.
None of these are mysteries or failures of implementation. They are consequences, and they are predictable once the mechanism is understood.
What follows in practice
Use these systems for work where the output can be checked, where fluency is genuinely useful, and where a draft that needs revision is more valuable than a blank page. Avoid relying on them for specific facts, citations or numbers where a confident wrong answer is worse than no answer.
That is a narrower recommendation than the enthusiasm suggests and a much broader one than the dismissal allows. Both positions tend to be argued by people who have not looked closely at what the systems do.
Where the reliable information is
Research papers, model documentation, technical writing from the organisations building these systems, and independent evaluation work. Most of it is freely available and considerably more measured than either the promotional material or the criticism built on top of it.
The field moves quickly enough that any general article, including this one, dates rapidly. Anything with consequences attached is worth checking against current documentation.
On the pace of change
Capabilities have moved quickly enough that specific claims about what models can and cannot do have a short shelf life. Several limitations described confidently a few years ago have been substantially reduced, and several that were expected to fall have not.
The underlying mechanisms have changed far less than the capabilities. Next token prediction, tokenisation, context limits and the absence of a verification step have all remained, which is why the same categories of failure keep recurring in new forms even as performance improves.
A note on evaluating claims
When a capability is announced, the useful questions are: measured on what benchmark, compared against what, evaluated by whom, and reproducible by anyone outside the organisation making the claim. Those four questions dispose of a considerable amount of what circulates.
Independent replication in this field is under-resourced relative to the scale of the claims being made, which is a structural problem rather than a criticism of any particular organisation. It means that a great deal of what is asserted has never been checked by anyone with an incentive to find it wanting.
One last observation
The most useful thing anyone can know about these systems is what they are optimising for, because everything else follows from it. A model trained to produce plausible text will produce plausible text, reliably, and regardless of whether the text is true.
That is not a criticism. It is a specification, and reading it as one makes the whole field considerably easier to think about clearly.
Further reading
Technical documentation from model providers, peer-reviewed research and independent evaluation organisations are the three places where this material is covered accurately.
All three are freely accessible, and all three are considerably drier and more useful than the commentary built on top of them.