Explicit completion criteria
You state up front, unambiguously, what finished looks like. Not improve checkout, but the exact condition that ends the task.
Comparison — — by Mahmoud Zalt
Devin is built for engineering teams who can write scoped, verifiable tickets. If nobody on your team can, here is what to hire instead.
Devin is built for engineering teams. Cognition describes it as the AI software engineer, built to help ambitious engineering teams crush their backlogs. That sentence is doing real work: it names the customer, the artifact, and the job. If you have a repository, a test suite, and a queue of tickets nobody has time for, you are the intended reader.
The product is unusually complete for that reader. Devin runs with an embedded IDE, a shell, and a browser, so it writes code, runs it, and tests it inside its own environment instead of handing you a patch to figure out. You can run up to ten concurrent sessions on the free and Pro plans, and unlimited concurrent sessions on Max, Teams, and Enterprise.
None of that is where a small team runs into trouble. The trouble sits upstream of the tool, in the part of the job Devin quite openly leaves to you. The vendor's own documentation is more candid about this than most, and it is the best evaluation material available.
Devin's documentation gives you a rule of thumb for what to hand it, and it is a short one. The docs say that if you can do it in three hours, Devin can most likely do it, and they add that it struggles with extremely difficult tasks. That is an honest ceiling and it is worth taking at face value.
If you can do it in three hours, Devin can most likely do it.
Read it as a scoping instruction rather than a complaint about the model. It means whoever hands Devin work has to look at a piece of the backlog and know, before starting, whether it is a three-hour job. Estimating that is itself a skill, and it usually comes from having built the thing before.
Three requirements sit inside Devin's own guidance for getting good results, and all three land on you rather than on the model. You write clear prompts with explicit completion criteria. You make tasks easy to verify, for example by having CI pass. And you break the work into well-scoped steps.
You state up front, unambiguously, what finished looks like. Not improve checkout, but the exact condition that ends the task.
The docs point at tasks that are easy to verify, such as CI passing. That assumes a test suite already covering the change.
The work arrives already decomposed. Somebody decided the order, the boundaries, and what each step is allowed to touch.
Roughly a three-hour piece of work for a competent engineer, judged correctly before the work starts.
There is nothing unreasonable on that list. It is close to what a good engineering manager gives a new teammate in their first week, and it is exactly why Devin performs well inside teams that already operate that way.
A small team without an engineering manager stalls on the brief, not on the model. The founder knows the outcome they want, invoices should stop bouncing, the onboarding email should go out when a trial starts, but they cannot express it as a completion criterion, cannot say which test proves it, and cannot decompose it into steps that fit inside three hours.
Hand that founder an autonomous coding agent and the loop breaks in a predictable place. The agent does something, the founder cannot tell whether it is right, and there is no CI signal to answer the question for them. The work is technically finished and practically unverifiable, which is worse than not started.
Devin's docs even carry a reliability caveat worth quoting: in some cases Devin may not function exactly as referenced, or documentation may be out of date. For a team with review capacity that is a normal caution to plan around. For a team with none, it is the entire risk.
The alternative is not a weaker version of the same thing. It is a different unit of purchase. Instead of buying an agent that consumes engineering tickets, you hire an AI Employee that consumes a plain-language brief and produces business work: the emails sent, the store updated, the report filed, the research done. Nobody has to translate an outcome into a ticket, because the outcome is the input. That is the unit we sell at Sistava, and it is a different job from the one Devin is built to do rather than a competing take on the same job.
Devin's pricing is public and readable, which is more than can be said for much of this category. There is a free tier, two individual plans, a team plan built from a base fee plus per-seat charges, and a custom enterprise tier.
| Plan | Published price | Concurrent sessions |
|---|---|---|
| Free | $0 | Up to 10 |
| Pro | $20 per month | Up to 10 |
| Max | $200 per month | Unlimited |
| Teams | $80 per month base, plus $40 per month per full developer seat | Unlimited |
| Enterprise | Custom | Unlimited |
The part to plan for is the variable layer. Paid plans can purchase extra usage which is consumed at API pricing, and Cognition states plainly that cost per message varies based on the model used, the task size and complexity, and the reasoning required. If your tasks are tightly scoped, that variability stays small. If they are vague, the tasks you could not scope are the ones that cost the most.
The briefing model is the whole difference. You describe the job the way you would describe it to a person joining your company, constrain it with rules written in the same plain language, then review what came back.
Notice which skills that sequence needs: knowing your own business, and being willing to read what came back. It does not need you to size a three-hour ticket or write the test that proves the job is done.
Memory is the other half of it. An AI Employee keeps context across runs, so a correction you made in March is still in effect in July. You are not re-explaining your customers, your tone, or your exceptions at the start of every session. The per-tool permissions, the plain-English rules, the approval gates and that memory are documented across the Sistava feature pages if you want to check the mechanics before you brief anything.
| Dimension | Traditional | With Sista |
|---|---|---|
| Intended buyer | Engineering teams working through a backlog | Business owners and small teams without an engineer |
| What you hand it | A scoped ticket with explicit completion criteria | A plain-language brief describing the outcome |
| How work is verified | Tasks that are easy to verify, such as CI passing | An activity feed recording every action with a screenshot |
| Where it operates | A codebase, through an embedded IDE, shell, and browser | Your connected tools, enabled or disabled per employee |
| Guardrails | Your review process and your test suite | Tool Rules in plain English, plus approval gates on consequential actions |
| Scope guidance | Roughly a three-hour task, by the vendor's own rule of thumb | Recurring business work running on a schedule |
| Continuity | Per session, with the context you supply | Memory carried across runs, month to month |
Neither column is a criticism. The comparison is about which sentence you can write on a Monday morning, and that is a fact about your team rather than about either vendor.
If you do have an engineer, the two are not mutually exclusive. Plenty of small companies run a coding agent inside the repository and an AI Employee across the rest of the business, because the work is different and so is the person reviewing it.
Use Devin if you have a codebase, a test suite, and at least one person who can write a ticket with a completion criterion in it. Under those conditions it is a strong choice, and the concurrency on the higher plans genuinely changes how much backlog a small engineering team can move in a week.
Use it especially where the backlog is full of well-understood work: the migration nobody started, the flaky test, the dependency bump, the endpoint that needs the same treatment as the last six. That is precisely the shape the three-hour rule describes, and it is a large share of most backlogs.
Do not use it as a substitute for having an engineer. That is the one job the documentation quietly rules out, and it is the one small teams keep walking into anyway.
If nobody on your team can write a ticket with an explicit completion criterion in it, the alternative is not another coding agent. It is an AI Employee you brief in plain language: you describe the outcome, connect the tools it needs, attach plain-English rules to each tool, and review an activity feed that records every action with a screenshot. What it produces is business work rather than code, which is usually what the team actually wanted.
Cognition publishes a free plan at $0, Pro at $20 per month, Max at $200 per month, Teams at $80 per month base plus $40 per month per full developer seat, and a custom Enterprise tier. Paid plans can purchase extra usage which is consumed at API pricing. Cognition also notes that cost per message varies based on the model used, the task size and complexity, and the reasoning required, so the variable layer moves with how well you scope the work.
Devin's documentation offers a rule of thumb: if you can do it in three hours, Devin can most likely do it. The docs also say it struggles with extremely difficult tasks. Treat that as a scoping instruction rather than a hard wall. Somebody on your side still has to judge whether a piece of work fits the ceiling before handing it over, and breaking larger work into well-scoped steps is explicitly the user's job.
Devin is an AI software engineer, so its output is code and its working environment is an embedded IDE, shell, and browser. Without a codebase there is nothing for it to change and no CI signal to verify it against. If your work is sending emails, updating a store, chasing invoices, or researching prospects, a coding agent has no surface to act on, and an AI Employee connected to those tools is the closer fit.
An AI software engineer consumes engineering tickets and produces code changes, verified by your tests. An AI Employee consumes a plain-language brief and produces business work across your connected tools, verified by reading what it did. The second keeps memory across runs, holds consequential actions for approval, and can drive a computer or a browser through a companion app, so the work never has to live inside a repository.
Often yes. A founder who can code is exactly the reader able to supply what the docs ask for: explicit completion criteria, verifiable outcomes, and well-scoped steps. Start on a lower tier, hand it the well-understood backlog rather than the ambiguous architecture work, and keep an eye on extra usage, which is consumed at API pricing. The trouble starts when the same founder reaches for it to do non-engineering work.
The most useful thing about Devin is how plainly it states its own conditions for success. Very few products in this category tell you, in their documentation, which buyer they expect and what that buyer has to bring to the table. Take those statements seriously and they will sort you into the right product in about a minute.
If you have the engineer, the tests, and the scoped ticket, Devin is a good answer and the three-hour rule will serve you well. If you have a business and nobody to write that ticket, hire an employee you can brief the way you would brief a person, then judge it by the work it hands back. Setting one up on Sistava takes a brief rather than a backlog, and you can see what the plans include on the pricing page.