For engineering managers who are hiring

Developer Onboarding Tool for Codebases and Codebase Onboarding for New Engineers

New hires lose their first weeks figuring out where things live and why the code works the way it does. CodeIndex indexes your GitHub repositories so a new engineer can ask "where do we handle refunds?" and get an answer that points to the exact files, instead of waiting for a senior developer to be free.

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14-day trial on the plan you choose. Card charged only when it ends. Works on private GitHub repos from day one.

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Short answer

A developer onboarding tool for codebases lets a new engineer learn an unfamiliar codebase by asking questions and searching by meaning, without pulling a senior engineer off their work for every question. CodeIndex does this for teams on GitHub: it indexes public and private repos, answers plain-English questions with citations to the files and lines it used, and costs a flat $49/month for 5 users or $149/month for 20 on annual billing ($99 and $299 month to month).

$49/mo

Starter, billed annually ($99 monthly). 5 users, 10 repos, 1,000 questions a month

$149/mo

Pro, billed annually ($299 monthly). 20 users, 50 repos, 10,000 questions a month

File types indexed, dependencies and build output skipped

14 days

Trial on any plan, card at checkout

New engineer on their first week exploring the company codebase with an AI code assistant

The new hire asks the codebase, not the senior engineer

Week one questions are always the same: where does this live, what calls it, why is it built this way. When a new engineer can ask those in plain English and get the exact files back, your senior people keep their focus and the first pull request lands days sooner.

What a new engineer can do in their first week

Most onboarding pain is the same dozen questions asked in slightly different ways. CodeIndex lets new hires answer them on their own and shows them the code the answer came from, so they learn the codebase instead of memorizing someone's explanation.

Ask where things live

"Where is the webhook signature checked?" returns the file and function, even if the code calls it something the new hire would never guess.

Get a flow explained end to end

Ask how an order moves from the API controller through the queue to the database and get a walk-through tied to real files, in the order the code runs.

Check what breaks before a first PR

Ask what calls a function or which modules depend on a class. New engineers make their first changes with far less fear of the ripple effects.

Search by meaning, not exact strings

Semantic code search finds the retry logic for failed payments when someone searches for "retry failed charges", whatever the variables are named.

Answers with sources, not guesses

Every answer lists the file paths and line ranges it used. A new hire can open them, read the real code, and trust what they learned.

One price for the whole team

Starter covers 5 people and Pro covers 20. The new hire, their onboarding buddy, QA and the product manager all use it without per-seat math.

Codebase onboarding options compared

There are four common ways teams get new engineers up to speed on a codebase. Each has a place. This is how they compare on the questions a new hire actually asks.

	CodeIndex	Internal docs and wiki	Senior engineer pairing	AI coding assistant chat
Answers "where is X handled?"	Yes, with file citations	Only if someone wrote it down	Yes	Often, limited to files in context
Stays current as code changes	Re-indexes the repo	Drifts unless maintained	Yes	Yes
Cost to the team	$99 to $299/month flat	Writing and upkeep time	Senior engineer hours	Per-seat subscription for every user
Available to non-developers	Yes, same team plan	Yes	Takes their time too	Needs a developer seat
Explains why decisions were made	Only what the code shows	Yes, when documented	Yes	Only what the code shows
Code hosts	GitHub	Any	Any	Depends on vendor
Best for	Self-serve answers across many repos	Architecture decisions and runbooks	Judgment, context and culture	Writing code inside the editor

These work together. CodeIndex does not replace an onboarding buddy or your architecture docs. It takes the repetitive "where is this" questions off the buddy's plate so pairing time goes to the things only a person can explain.

How to set up codebase onboarding in an afternoon

1
Start the trial

Pick a plan and get 14 days on it. The card is charged only when the trial ends.
2
Connect the repos a new hire touches

Paste the GitHub URLs of the services they will work on, public or private. Start with the two or three they meet in week one.
3
Invite the new engineer and their buddy

Add them to your team. The buddy can seed a short list of starter questions that match your onboarding checklist.
4
Let them ask before they interrupt

The new hire asks CodeIndex first and brings the harder why-questions to their buddy. Answers link to code, so review stays fast.

Who uses CodeIndex for developer onboarding

Teams hiring several engineers a quarter

When three people join at once, the same questions hit the same senior engineers three times. Self-serve answers stop that from eating a sprint.

Companies with a large legacy codebase

Old services with thin documentation are where new hires stall longest. Asking the code directly beats hunting for the one person who remembers how billing works.

Contractors and agency developers

Short engagements cannot afford a two-week ramp. Index the client repo on day one and have the whole team question it.

Engineers switching teams internally

Moving from the mobile team to payments is a new codebase too. Internal transfers get the same self-serve onboarding as external hires.

What is the best developer onboarding tool for a codebase?

The best developer onboarding tool for a codebase is one that answers a new engineer's questions from the code itself, points to the exact files, and stays accurate as the code changes. For teams on GitHub, a codebase Q&A tool like CodeIndex does that at a flat team price, while docs and pairing cover the context code cannot show.

HR onboarding platforms handle accounts, paperwork and checklists. They do not help anyone understand your order service. Code-focused tools fall into three groups: wiki generators such as DeepWiki, code search platforms such as Sourcegraph, and question-answering tools such as CodeIndex. If your team mostly asks "where" and "how" questions, Q&A with citations gets new hires moving fastest. We compare the wiki approach in our DeepWiki alternative breakdown.

How long does it take a new developer to understand a codebase?

It usually takes a new developer several weeks to be productive and a few months to feel at home in a large codebase, depending on its size, age and documentation. The biggest delays are finding where things live and waiting for answers, and both shrink when a new hire can ask the code directly.

You can measure this on your own team. Track time to first merged pull request and time to first on-call shift for each hire. If those numbers drop after you give new engineers self-serve answers, the tool is paying for itself.

How do you onboard new developers to a large codebase?

Onboard new developers to a large codebase by giving them a map, a first small task, a named buddy, and a way to answer routine questions on their own. Start with the services they will touch in week one, not the whole system, and have them ship a small change early so they learn the build, test and deploy path.

The self-serve piece is where most teams struggle. Without it, every "where is this" question becomes a Slack message to a senior engineer. With a codebase Q&A tool, the new hire asks first, reads the cited code, and brings only the judgment calls to their buddy.

How much does a developer onboarding tool cost?

CodeIndex costs $99 a month for up to 5 users and 10 repositories, $299 a month for up to 20 users and 50 repositories with API access, and $999 a month for unlimited users with SSO/SAML. Every plan includes semantic code search, codebase Q&A and code explanations on private repos. See CodeIndex plans and limits for the full breakdown.

Compare that with the cost of slow onboarding. If a senior engineer spends five hours a week answering a new hire's questions for their first month, that is about 20 hours of senior time per hire. Enterprise code platforms cost far more: Sourcegraph starts at $16,000 a year, as we cover in our Sourcegraph pricing guide.

Can AI help new developers understand a codebase?

Yes. AI helps new developers understand a codebase by answering questions in plain English and explaining how files connect, as long as the answers are grounded in the actual code and show their sources. Answers without citations are risky for onboarding, because a new hire cannot tell a confident guess from the truth.

That is why CodeIndex returns the file paths and line ranges behind every answer. The new engineer reads the real code, which is how they actually learn it, and a reviewer can check the source in seconds.

Frequently asked questions

Does CodeIndex work with private GitHub repositories?

Yes. Every plan, including the $99 Starter plan, indexes private and public GitHub repositories. CodeIndex currently supports GitHub only, so teams on GitLab or Bitbucket would need a different tool.

Can non-engineers use it during onboarding?

Yes. Product managers, QA and support engineers can ask questions like "what happens when a card payment fails?" on the same team plan. Starter includes 5 users and Pro includes 20, so they do not need separate developer seats.

Does it replace our onboarding documentation?

No. Docs and a buddy still explain decisions, conventions and team culture. CodeIndex takes over the repetitive questions about where code lives and how it works, which frees your senior engineers for the conversations that need a person.

Which files does CodeIndex index?

CodeIndex indexes source code in 40 file types and skips vendor folders, node_modules, build output, lockfiles and minified bundles, so answers come from your application code rather than third-party libraries.

Is there a trial?

Yes. Every plan starts with a 14-day trial of the plan you choose. The card is collected at checkout and charged only when the trial ends.

Give your next hire a faster first month

Paste a GitHub repo URL, invite your new engineer, and start your 14-day trial. Card charged only when it ends.

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