Informatica Developer Interview Questions 2026

Last updated: September 22, 2026

By Mike Carter, Managing Director, KORE1

Informatica developer interview questions in 2026 should test how a candidate proved a migrated mapping still produced the same numbers, which Informatica products they actually worked in, and what their old PowerCenter jobs could not carry to the cloud. Syntax questions about transformation types are answerable from any certification study guide. The questions below are not, because they ask what the person did when the converted job ran green and the totals still came out wrong.

A property and casualty insurer in Des Moines finished a PowerCenter migration last spring. Three hundred and forty mappings, eight months, a conversion utility that did most of the lifting. Every job ran. Green across the board, in fact, which is precisely the part that made the following three months so unpleasant for a director who had already sent the all-clear email to his CIO.

In August their actuarial team pulled earned premium for the quarter and found the number short by about four tenths of a percent. On roughly $480 million of quarterly earned premium that is a little under $1.9 million, sitting in nobody’s ledger, with a filing deadline two weeks out.

The cause was one lookup.

On-prem, a Lookup against their policy dimension had been set years earlier to return the last matching row, which mattered enormously because that dimension kept history and any given policy could be sitting in there as four different versions of itself with four different premium figures attached. The converted mapping returned the first match instead. Same inputs, same target table, same row count. Different rows. A smoke test could not see it and a record count could not see it, because the count was identical.

Nobody had run the old job and the new job side by side and compared what came out. Not once. Not across three hundred and forty mappings. I asked their director why, months later, and his answer has stayed with me. No interview they had ever run included a question about it. So nobody on the team thought of it as work. It was just assumed, the way you assume the lights.

Worth saying plainly. KORE1 gets paid when a company hires a data integration person through us, and our Informatica developer staffing desk, which sits alongside ETL developer staffing inside our IT staffing services practice, is where these searches land. You can run everything below without calling anyone. Plenty of our clients do, then call us only when the second search stalls.

Ask Which Window Was Open

Start here. It changes every other question you ask.

“Informatica” on a resume is a company, not a skill, and the same eight-year claim can describe jobs that share almost no daily work. One trap in particular catches hiring teams who have not lived in this stack. The Eclipse-based client tool used to build data quality rules in Informatica Data Quality is literally named Informatica Developer. Literally. So a candidate who spent four years writing standardization and matching rules is telling the truth, by the letter, when their resume says Informatica Developer. They may have never opened a PowerCenter workflow.

Neither background is wrong. They are just not interchangeable, and the req almost never says which it wants. If yours does not, our Informatica developer job description template is a faster fix than another round of interviews.

One question before the first technical round sorts most of a pipeline. Which Informatica client tool did you have open the most hours last year? Not which products they know. Which window was actually on their screen. People answer that one honestly, partly because it does not sound like a test and partly because there is no obviously correct answer to game toward, which is the same reason it works on candidates who have been through a lot of interviews already.

Then ask what they did in it. A person who names the tool and then describes a Tuesday is a different candidate from one who names the tool and stops. If the answers keep landing on connecting systems rather than loading a warehouse, you may be running an integration engineer search under the wrong title, and the questions for that role are different enough to matter.

Why This Seat Is Open Right Now

Two paragraphs of context. It decides what the job is.

PowerCenter 10.5 reached the end of standard support on March 31, 2026, and the extended support that replaced it runs to March 31, 2027. That date has already passed once. As I write this in September 2026, most companies still running it are paying a premium for coverage that ends in about six months, which is why so many of these searches arrive with a deadline attached rather than a headcount plan. Informatica itself now points customers at a cloud modernization path off the product, and Salesforce closed its acquisition of the company in November 2025, so nobody is expecting the on-premises line to get livelier.

So the candidate pool splits. People who have been through a migration, and people who are about to be. That split is the question sitting underneath all the technical ones, and it is worth more than any single answer they give you. Candidates who have done it talk about the existing system before they talk about the tool. Every time. It is reliable enough that I use it on first calls now, and it has not failed me yet.

The Nine Questions Worth an Hour

None of these are trivia. Every one came out of a search where something had already gone wrong, usually at a client who had run a perfectly reasonable-looking loop. Reasonable is the problem.

How did you prove a converted mapping produced the same output as the original?

Lead with this one. Ask it early. Before the candidate has warmed up and started performing.

A strong answer has mechanics in it. Parallel runs for a defined window, both targets landing in separate schemas, then a row count, then a full column-level compare on a key set, then a checksum or hash on the measures that finance cares about. Better answers mention the boring part. Who signed off. What the tolerance was. Somebody always has to decide whether a two-cent difference on a $12 million total is a defect or arithmetic, and that somebody is rarely the developer.

Weak answers say the job ran successfully. Ask again, differently. If the second answer is also about the job running, you have someone who has migrated code and never validated data. Two different people. Two different hires.

Which mappings did the conversion utility hand back that you threw away and rebuilt?

Automated conversion is good at producing a cloud mapping that works. It is not good at producing one that belongs in the cloud. Row-by-row logic that made sense against an on-prem Oracle box often should be re-authored to push the work down into Snowflake or Databricks or whatever the target is now.

The answer you want names a specific mapping and the reason. A nightly aggregate that took nine minutes on-prem and forty in the cloud, until somebody rewrote it as SQL ELT. That kind of thing. Specifics. Someone who says everything converted cleanly either had very few jobs to move or was not the one watching the runtimes.

Where does your Secure Agent run, and what did the network team have to open?

A quiet question. It sorts people fast. The Secure Agent is the runtime, and in most real deployments it does not get to sit wherever it wants. It should not share a box with a running PowerCenter installation, for resource reasons alone. It needs reach to every source and target the old Integration Service could reach, which means ODBC drivers installed on that server, environment variables set on that server, SFTP endpoints allowed from that server’s address and not the old one.

People who have shipped this bring up firewall tickets and driver versions before anyone asks them to. Nobody coaches that. People who have only built mappings describe the agent as a checkbox on somebody else’s install form, and the distance between those two answers is roughly four months of your project schedule.

You had an unconnected Lookup called from three expressions. Walk me through what you checked.

Unconnected lookups are everywhere in old PowerCenter code, and they are the kind of thing that survives conversion technically while changing behavior quietly. Return port. The policy on multiple match. What comes back when nothing matches. Whether the cache was persistent, and whether anything downstream quietly depended on it being stale.

Our Des Moines insurer lost $1.9 million of visibility to exactly this category of detail. Ask it.

A shell script rewrote your parameter file before every run. Where does that script live now?

On-prem, a lot of scheduling logic lives outside Informatica entirely. Shell scripts. Cron. Control-M. A wrapper somebody wrote in 2011 and has not touched since. Parameter handling in the cloud is not identical, scoping rules differ, and the script that used to sit on the same server as the Integration Service may not have anywhere to live anymore.

Good candidates have a story about finding an undocumented wrapper two weeks before cutover. Most shops have one. Some have nine. Nobody wrote them down.

Tell me about a job that was fast on-prem and slow after the move.

Everyone who has done this has one. If a candidate cannot produce one, I stop believing the rest of the timeline.

A taskflow dies on step four of seven. Walk me through the restart.

Restart and recovery behavior is one of the genuine differences between PowerCenter sessions and cloud taskflows, and it surfaces at 2 a.m. rather than in a design review. Listen for idempotency. Does a restart re-insert rows? Is there anything in the target that would stop it? Most candidates have never been asked this out loud, so give them a second to think.

What happened to your IDQ rules?

If the company had Informatica Data Quality, ask this one every time. It separates the pool almost perfectly. IDQ rules are built in the Developer tool as mapplets and rule specifications, with reference tables, scorecards, and often Address Verification doing postal standardization behind them. Cloud Data Quality in IDMC is the successor. The move is not a lift.

Reference tables need somewhere to go. Address verification licensing is its own conversation, and it is not a short one. Rule specifications that a business analyst maintained in the Analyst tool need an owner on the other side. In about half the projects I have seen, nobody named that owner.

A candidate who says data quality belonged to another team is being honest, and that is a perfectly acceptable answer to give. It also tells you exactly which seat you have not filled yet.

Which service in your PowerCenter domain kept you off CDI-PC?

An expert-level question, and you do not need the candidate to get it. CDI-PC supports the classic Repository Service and Integration Service. A domain carrying other services has to be split before it can move. That is a real project, with a real schedule, and it usually gets discovered late.

A candidate who lights up here has been in the room when somebody found out. Move them to a second round fast. They will not be available long.

Three Answers That Should Worry You

Not wrong answers. Nothing so easy. Answers that sound finished and are not.

“The conversion tool handled it.” It handled the syntax. Somebody still had to decide what to do about the mappings it converted into something that technically ran. Ask which ones those were. If the candidate cannot name one, they were not close enough to the work to be useful to you.

“We tested everything before go-live.” Tested how? A job completing is not a test. Push until you hear either a row count or a comparison, and if you hear neither, you have found the gap this whole page is about.

“That was handled by another team.” Often true and perfectly honest. The follow-up matters more than the answer. Ask what they did when that other team got something wrong, because everybody who has worked alongside a separate validation group has a story about the week the two sides disagreed.

None of these disqualify anyone on their own. All three, in one conversation, describe somebody who was in the building during a migration rather than on it.

The Reconciliation Nobody Assigns

Go back through the last data migration your company ran, whatever the technology. Find the person whose job was to prove the new outputs matched the old ones.

You will not find one. The work gets folded into the developer’s role, and the developer is measured on whether jobs run, so it is the first thing squeezed when the date slips. Then it becomes the finance team’s problem. In a quarter that already closed.

Make it a named deliverable in the req. Then say it out loud in the interview, that part of this job is proving the numbers, and watch the candidate’s face. Some deflate. They wanted to build. A few light up instead, and those ones keep talking past the question. A compare harness at the last place. A config file with every mapping in it, key columns, tolerances. Nightly run against both targets. A report that went to a staff accountant who ignored it for fourteen months and then needed it very badly, on one particular Thursday in October, when somebody upstream changed a currency code without telling anyone.

That second group is small. It is also the group that keeps your CFO from finding out about a problem before you do.

What the Answer Is Worth Paying For

One reference point. Then the part that actually moves your number.

The closest federal occupation code to this work is database architects, 15-1243, and the May 2025 federal wage data for that code puts the national median at $139,500 a year, with the tenth percentile at $86,240 and the ninetieth at $204,000. It counted 67,140 people, and projects growth through 2034 running faster than the average occupation. Treat that as the floor of the conversation rather than the answer, because the code is broad and swallows a lot of steady database work that looks nothing like a migration.

What moves the number is the thing this whole page is about. Someone who has finished a migration end to end, reconciliation included, gets priced by scarcity rather than by title. In our searches this year those candidates cleared the top of the published bands, and a few cleared them by a distance. Our Informatica developer salary guide breaks the bands out by product lane, and the salary benchmark assistant will give you a range for your own market before you post anything.

For work with an end date the arithmetic usually favors contract. You stop paying for the seat when the project stops, and you avoid making a permanent hire against temporary work. Our clients run these as contract staffing engagements more often than not, and where you want to watch someone work before committing, contract-to-hire is how most of these seats actually convert. Where the system is staying and somebody has to own it afterward, direct hire is the honest answer.

Whatever the band, the same answer separates the top of it from the middle. Here is what that sounds like on the question that matters most.

That last row is the one I listen hardest for. Candidates who volunteer the time they were caught out are, almost without exception, the ones who built something afterward so it could not happen twice.

Who Should Be in the Room

Three conversations. Four if direct reports are attached.

First, twenty-five minutes on the phone, most of it on the client tool question and on what they were responsible for. Sizes. How many jobs, how many sources, what the targets were, who else was on the team. You are not testing anything yet. You are finding out whether the words on the resume match the work.

Second, the technical conversation. An hour, built from the nine questions above, with the two or three that match your situation pushed hardest.

Here is where most loops quietly fail, and it has nothing to do with the questions. Somebody in that room has to be able to tell a real answer from a fluent one, and at a lot of companies nobody can, because the person who could left and that is why the seat is open. A director who has never opened the tool cannot referee a conversation about it. They will hear confidence and score it as competence, which is how the Des Moines insurer ended up where they did.

If you do not have that person in house, borrow one. I mean that literally. An outside reader for sixty minutes costs almost nothing next to a bad hire on a deadline, and the good ones will tell you within ten minutes of the call ending whether the candidate has carried this work or watched it.

Third, twenty minutes reading real code. Put a job from your own system on a screen, redacted, and let them talk through it, what it does, where it would break, what they would want to know before touching it. Pick one with something ugly in it. Everyone has one. Everyone. The candidate who finds the ugly thing without being told it is there is the candidate.

The Questions That Come Back to Us

We are still entirely on PowerCenter. Is a cloud-only candidate a mistake?

Usually, yes, at least for the first hire, because somebody has to read twenty-year-old mappings that nobody documented before anything can be moved anywhere.

The reading is the hard part, and it is the part cloud-only candidates have never had to do. Hire someone who can read the old code first, then add cloud-native people once there is a target design worth building against. Reverse the order and you end up with a team that is fluent in a platform nobody has migrated anything to yet, which looks like progress on a status report and is not progress anywhere else.

Nobody on our side can judge the technical answers. Now what?

Borrow an evaluator for one hour, from a partner firm, a contractor you trust, or your systems integrator, and give them the nine questions ahead of the call.

This happens more than anyone admits at a conference. Informatica shops tend to run on one or two long-tenured people, and when one of them finally leaves, the person hiring the replacement is a director who has never once opened Workflow Manager and has no way to tell a careful answer from a confident one. Running the loop without an evaluator is how you hire on confidence. An outside reader for sixty minutes is cheap insurance. Most of the contractors on our bench will do it without being asked twice.

Every resume says Informatica. Can we sort them before the first call?

Partly. Look for client tool names and version numbers rather than product names, since those are specific enough that people do not fake them convincingly.

Workflow Manager, Repository Manager, a version like 9.6 or 10.5. That is PowerCenter. Developer tool, Analyst tool, rule specifications, scorecards. That is data quality. Secure Agent, mapping tasks, taskflows, an R-number certification. That is cloud. Someone who lists all three in a single sentence with no detail underneath any of them is usually describing a training course rather than a job, which does not disqualify them at all but does mean the first call should be a different set of questions than the one you had planned.

Our finalist has never run a migration. Is that disqualifying?

No, but it changes what you are buying, and it should change the plan you build around them rather than the decision itself.

Plenty of strong people maintained a stable system for years and were never handed a cutover, which is a statement about their employer and not about them. What you lose is the instinct for where things go quietly wrong, and that instinct is most of what this page is about. Two ways to cover it. Pair them with a contractor who has done three of these for the first few months, or narrow the role so somebody else owns the comparison work. What does not work is hiring them, handing over the deadline, and hoping. Ask the question directly in round two. Candidates are usually honest about it, and how they answer tells you whether they know what they have not done.

Should the person who proves the numbers be the person who wrote the jobs?

Ideally not, for the same reason you do not have a writer copy-edit their own draft, though on a small team it is often unavoidable and can be managed.

Somebody who spent four months building a job has a picture in their head of what it should produce, and that picture is exactly what a comparison is supposed to test. Where you have two people, split it. Where you have one, make the comparison a written artifact with a defined tolerance, signed off by somebody on the business side who does not care how the job works and only cares what the total says. Ask candidates which arrangement they had. The ones who have been both the builder and the checker will tell you which they preferred, and why, and the answer is usually informative about how they think.

How do we run a real exercise without handing over real data?

Redact the job, not the logic. Rename the tables and columns, strip the connection details, and leave the transformation exactly as it is, because the transformation is the part you are testing.

Nobody needs your actual customer table to tell you what a job does. Swap the names for something neutral, blank the credentials, and keep every lookup, every expression, every condition intact. Twenty minutes on a screen inside the interview, nothing sent home, nothing retained. If your security team still objects, use a job from a system you have already decommissioned. Most companies have one sitting in a repository that nobody has opened in three years, and for this purpose it works just as well. Scoping and pricing come before questions anyway. Our guide to hiring an Informatica developer covers that ground, and the broader ETL developer version covers it if your shop runs more than one tool. One more thing worth knowing. These searches land next to data architect staffing more often than not, because somebody has to own the target design and it is rarely the person writing the jobs.

What Des Moines Asks Now

The Des Moines insurer closed their gap eventually. It took six weeks, a contractor from our bench, and a compare harness that should have existed before the first mapping moved. While they were in there they turned up two more mappings carrying the same class of defect, both small enough that nobody would have noticed for another year, and both guaranteed to surface eventually in some quarter that nobody had planned around.

Their next data integration hire got a different interview. Same technical depth, one addition. Every candidate was asked how they would prove that a migrated job still produced the right numbers, and the answers sorted the pipeline faster than anything else on the list. The person they hired had built a compare framework at a health system in Minneapolis and talked about it for eleven minutes without being prompted.

That is the whole test, really. Anyone can tell you what a Lookup transformation does. The people worth hiring can tell you how they found out theirs was wrong.

If you want help running this search, talk to our data integration recruiters. Our Informatica recruiters place talent on contract, contract-to-hire, and direct hire across more than thirty metro areas, and a year after the start date, 92 percent of those hires are still in the seat. Ask the reconciliation question first.