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Huntington Bancshares Software Engineer Interview Guide

Huntington Bancshares Software Engineer interview guide: reported rounds, questions and how candidates describe the process.

The 60-second brief

As a Software Engineer at Huntington Bancshares, you play a pivotal role in shaping the digital future of one of the country's most respected regional banking institutions. In this role, you are not just writing code; you are building and maintaining the secure, scalable, and highly reliable financial systems that millions of consumers and businesses rely on daily. From digital banking applications and mobile platforms to robust backend APIs and core banking infrastructure, your work directly impacts customer financial well-being and operational efficiency. The engineering organization at Huntington Bancshares is deeply committed to modernization, cloud migration, and adopting modern software development practices.

This guide is scoped to a Software Engineer candidate at Huntington Bancshares.

Focus areas

  • AWS (Amazon Web Services)
  • Coding Challenges
  • Firebase

The Huntington Bancshares interview process

Huntington Bancshares candidates report 3 rounds over 3-5 weeks. The stages below are what candidates describe, not a published process.

Initial Screening Call

A conversation with a recruiter to discuss your background, career goals, and alignment with the role's requirements.

What to demonstrate

  • A conversation with a recruiter to discuss your background, career goals, and alignment with the role's requirements
  • Depth in AWS (Amazon Web Services)

How to prepare

  • Be able to walk your CV end to end in two minutes, and say why this company specifically.
  • Have your salary expectations, notice period and location constraints ready, and ask for the rest of the loop in writing.

Technical and Behavioral Evaluation

Involves panel interviews, live coding challenges, or deep-dive resume reviews conducted over video conferencing.

What to demonstrate

  • Involves panel interviews, live coding challenges, or deep-dive resume reviews conducted over video conferencing
  • Depth in AWS (Amazon Web Services)

How to prepare

  • Prepare three examples from your own work, each with a decision you made and an outcome you can quantify.
  • Re-read the description of the technical and behavioral evaluation above and write down what you would ask to confirm before it.

Final Stages

Conversational yet technically rigorous meetings with engineering managers and senior leaders to assess technical depth and cultural fit.

What to demonstrate

  • Conversational yet technically rigorous meetings with engineering managers and senior leaders to assess technical depth and cultural fit
  • Depth in AWS (Amazon Web Services)

How to prepare

  • Answer aloud and timed: Explain how garbage collection works under the hood in Java.
  • Answer aloud and timed: Walk me through the architecture of a recent system you designed. What were the key bottlenecks?

Where candidates lose points

Master Your Resume Details

Do not list any technology on your resume that you cannot discuss in depth. Be ready to explain the architecture of your past projects, why you chose specific tools, and what trade-offs you made.

Prepare for Live Coding

Even if a recruiter suggests the interview will be conversational, always be prepared for a live coding challenge. Practice basic algorithms, string manipulation, and data structure usage on collaborative coding platforms.

Emphasize Security and Quality

In banking, security, data integrity, and thorough testing are paramount. Whenever you discuss your work or solve a coding problem, highlight how you ensure code quality, handle errors, and secure sensitive data.

Questions & practice

How does memory allocation work in your primary programming language, and how do you prevent memory leaks?

Medium · Technical & Core Programming Concepts

Approach

  1. Say what the runtime actually does before reasoning about the code.
  2. Name what is shared across threads and what owns each piece of state.
  3. Identify the window where an invariant is briefly untrue.
  4. Distinguish a value from a reference to it, and say which one you handed out.

Follow-up

  • What happens if two callers reach this at the same time?
  • Where could this allocate more than you expect?

Explain how garbage collection works under the hood in Java.

Medium · Technical & Core Programming Concepts

Approach

  1. Say what the runtime actually does before reasoning about the code.
  2. Name what is shared across threads and what owns each piece of state.
  3. Identify the window where an invariant is briefly untrue.
  4. Distinguish a value from a reference to it, and say which one you handed out.

Follow-up

  • What happens if two callers reach this at the same time?
  • Where could this allocate more than you expect?

Archive a resource graph without breaking live references or recursing

Medium · graph traversal · topological order · tenant isolation

Resources reference other resources within a tenant; for the largest tenant the reference table holds up to 2,000,000 nodes and 8,000,000 edges. Archiving a resource must archive everything reachable from it that nothing outside the set still references, refuse when a live external referrer exists, and terminate when references form cycles, which they legitimately do. Produce the archive order and the refusal list, targeting O(V+E). Say what stops the traversal crossing a tenant boundary, and why recursion is the wrong control structure at this size.

Approach

  1. Load the subgraph with the tenant predicate on both endpoints of the edge, not only on the side you started from. Scoping the left table alone is the classic cross-tenant leak: one mis-entered edge then pulls another tenant's resources into the traversal and, worse, into the archive.
  2. Traverse iteratively with an explicit stack. A 2,000,000-node graph can hold a chain deep enough to exhaust a native stack in the low tens of thousands of frames, and that failure is a process crash rather than an error you can return.
  3. Treat cycles as data rather than corruption: compute strongly connected components with Tarjan in O(V+E) using its own explicit stack, then condense. The condensation is a DAG, so a topological order over it gives the archive order, and every member of a component archives in one transaction because no order within a cycle is valid.
  4. Decide refusals with reverse edges. A candidate is archivable only if every in-edge originates inside the candidate set, so build the transpose or count in-degrees restricted to the visited set, and emit each blocked resource with the id of the external referrer, which is the only part of the answer an operator can act on.

Follow-up

  • The graph is read in one query and the archive writes a minute later. What can change in between, and how do you make the write safe?
  • The candidate set is 400,000 resources. Is that one transaction, and if not, what does a half-finished archive look like to a reader?

How do you optimize a slow-performing database query in a relational database?

Medium · Technical & Core Programming Concepts

Approach

  1. Name the grain you start from and join outward from it.
  2. Check whether any join is one-to-many before aggregating, or the sums inflate.
  3. Say which index the query would use, and what makes it unusable.
  4. Handle the rows that do not match: that is usually the actual question.

Follow-up

  • How does the query change if that join becomes one-to-many?
  • What happens to this when the table is ten times larger?

Denormalise tenant onto revisions and backfill it live

Hard · denormalisation · online migration · backfill

resource_revision (revision_id, resource_id, version, actor_user_id, change_kind, patch, request_id, created_at) has 400M rows and no tenant column; tenant_id lives only on resource. Two reads need it: a tenant-scoped audit feed ordered by created_at DESC, and an offboarding purge. Both join back to resource today. Justify adding tenant_id to resource_revision against those two reads, name the anomaly the copy introduces and the constraint that prevents it, then give the ordered migration for a live table taking 1.2k writes/second — the lock each step takes, how the backfill is batched, and where each step stops being reversible. PostgreSQL 16.

Approach

  1. Justify from the access path rather than from taste. Without the column, the audit feed either scans resource_revision by created_at and discards other tenants' rows, or resolves the tenant's resource_ids first and probes with them — both proportional to the tenant's whole history rather than to one page. With (tenant_id, created_at DESC, revision_id DESC) it is a seek that stops at 50 rows, and the purge becomes a ranged delete instead of a join.
  2. Name the cost exactly: a second copy of a fact can disagree with the first. Make the disagreement unwritable rather than documented — add UNIQUE (resource_id, tenant_id) on resource so it can serve as a foreign-key target, then FOREIGN KEY (resource_id, tenant_id) REFERENCES resource (resource_id, tenant_id) on the revision table. A revision can then only ever carry its parent's tenant.
  3. Step one, expand: ALTER TABLE resource_revision ADD COLUMN tenant_id BIGINT NULL, with no default, so it is a catalogue change and no rewrite. It still needs ACCESS EXCLUSIVE for an instant, and that instant queues behind the longest open transaction on the table while every later query queues behind it — set lock_timeout to 2s and retry rather than wait.
  4. Step two, dual-write: deploy the writer that populates tenant_id on every new revision while reads still use the join. Reversible by redeploying the previous build, because nothing reads the column yet.

Follow-up

  • The backfill is half finished and a rollback is required. What state is the table in, and what does the previous build do with a half-populated column?
  • How do you verify the backfill actually finished, given rows are still being inserted while it runs?

Explain the difference between inheritance and composition in Object-Oriented Programming.

Medium · Technical & Core Programming Concepts

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. Work from the requirement backwards to the design.

Follow-up

  • What assumption would you test first?
  • How would you know your answer was wrong?

What are the differences between REST and gRPC, and when would you choose one over the other?

Medium · Technical & Core Programming Concepts

Approach

  1. Say who the caller is and what they do when the call fails halfway.
  2. Define the identity of a request so a retry cannot double-apply it.
  3. Separate accepted, pending, failed and confirmed; they are different facts.
  4. Design the error taxonomy before the success shape; callers branch on it.

Follow-up

  • What happens if the caller retries after a timeout?
  • How does a client discover it is on an old version of this contract?

Walk me through the architecture of a recent system you designed. What were the key bottlenecks?

Medium · Resume-Based & Architectural Justificati

Approach

  1. Fix the scope first: who calls this, how often, and what they do when it fails.
  2. Name the read and write paths separately; they rarely have the same bottleneck.
  3. Choose a partition key and say what query it makes expensive.
  4. State the consistency you need, and where you are willing to be stale.

Follow-up

  • What breaks first when traffic grows ten times?
  • How does this behave when that dependency is down for an hour?

Why did you choose the specific database or cloud services for the project listed on your resume?

Medium · Resume-Based & Architectural Justificati

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. Work from the requirement backwards to the design.

Follow-up

  • What assumption would you test first?
  • How would you know your answer was wrong?

How did you ensure security and data encryption in transit and at rest in your previous applications?

Medium · Resume-Based & Architectural Justificati

Approach

  1. Say who the caller is and what they do when the call fails halfway.
  2. Define the identity of a request so a retry cannot double-apply it.
  3. Separate accepted, pending, failed and confirmed; they are different facts.
  4. Design the error taxonomy before the success shape; callers branch on it.

Follow-up

  • What happens if the caller retries after a timeout?
  • How does a client discover it is on an old version of this contract?

What design patterns did you implement in your past projects, and what specific problems did they solve?

Medium · Resume-Based & Architectural Justificati

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. Work from the requirement backwards to the design.

Follow-up

  • What assumption would you test first?
  • How would you know your answer was wrong?

Exports duplicate a row range about once a week

Hard · leases · clock skew · idempotency

Roughly once a week an export writes a file containing a duplicated range of rows. The affected job_run rows show attempt = 1, status = succeeded, one started_at, and a lease_owner naming a different host from the one whose logs show the job starting. Leases last 30 seconds and are heartbeated every 10 from inside the handler; lease_expires_at is computed on the worker and compared against the database's now(). Find the mechanism, and give a fix that holds even if you cannot fix the clocks.

Approach

  1. Start from the fact that eliminates the obvious answer. attempt = 1 means no retry was recorded, so this is not a re-run after failure; two workers ran the same row concurrently and the takeover path never touched the counter. lease_owner naming a host other than the one that started the job is the same statement from the other side.
  2. Enumerate the mechanisms that cause a premature takeover, then find the signal that separates them. Either the lease genuinely expired because the heartbeat did not fire, which is what happens when the heartbeat runs on the handler's own thread and the handler makes a long blocking call, or it only appeared expired because two clocks disagree, since lease_expires_at is written from the worker's clock and evaluated against the database's. The discriminator is the distribution: incidents clustered on the longest exports indict the heartbeat, incidents clustered on one host indict skew. Measure both, and measure each host's offset against the database directly.
  3. Read the reclaim query precisely. In PostgreSQL now() is transaction start time, not statement time, so a reclaimer holding a long transaction compares against an older timestamp than expected; clock_timestamp() is the statement-time function. This is worth ruling in or out before you redesign anything, because it changes which rows look expired.
  4. Remove the second clock rather than trying to synchronise it. Issue and extend the lease in the database, with lease_expires_at = now() + interval '30 seconds' in both the claim and the heartbeat, so exactly one clock is ever compared and worker skew stops mattering to this predicate.

Follow-up

  • The displaced worker has already streamed half the file to object storage. What makes that side effect safe to repeat?
  • You now count takeovers. What alert fires on that counter, and at what threshold?

Suggested practice checklist

Built from the rounds and topics Huntington Bancshares candidates report.

Day 1 — Map the Huntington Bancshares loop

  • Write out the reported sequence: Initial Screening Call, Technical and Behavioral Evaluation, Final Stages.
  • For each round, write one sentence on what it is judging, from the description above, and mark the one you are least ready for.

Deliverable: A one-page map of the 3 reported rounds, with the weakest marked.

Day 2 — Work AWS (Amazon Web Services)

  • Spend the session on AWS (Amazon Web Services), which Huntington Bancshares candidates report being tested on.
  • Write one worked example in AWS (Amazon Web Services) and time yourself on it.

Deliverable: One timed worked example in AWS (Amazon Web Services).

Day 3 — Work Coding Challenges

  • Spend the session on Coding Challenges, which Huntington Bancshares candidates report being tested on.
  • Write one worked example in Coding Challenges and time yourself on it.

Deliverable: One timed worked example in Coding Challenges.

Day 4 — Work Firebase

  • Spend the session on Firebase, which Huntington Bancshares candidates report being tested on.
  • Write one worked example in Firebase and time yourself on it.

Deliverable: One timed worked example in Firebase.

Day 5 — Answer out loud: Technical & Core Programming Concepts

  • Answer aloud, timed: Explain the difference between inheritance and composition in Object-Oriented Programming.
  • Answer aloud, timed: How does memory allocation work in your primary programming language, and how do you prevent memory leaks?

Deliverable: Spoken answers to 2 reported Technical & Core Programming Concepts question(s), under time.

Day 6 — Answer out loud: Resume-Based & Architectural Justifications

  • Answer aloud, timed: Walk me through the architecture of a recent system you designed. What were the key bottlenecks?
  • Answer aloud, timed: Why did you choose the specific database or cloud services for the project listed on your resume?

Deliverable: Spoken answers to 2 reported Resume-Based & Architectural Justifications question(s), under time.

Day 7 — Answer out loud: Behavioral & Cultural Alignment

  • Answer aloud, timed: Tell me about a time you had a technical disagreement with a teammate or architect. How did you resolve it?
  • Answer aloud, timed: Describe a situation where you had to deliver a project under a tight deadline with incomplete requirements.

Deliverable: Spoken answers to 2 reported Behavioral & Cultural Alignment question(s), under time.

Behavioural preparation

Behavioural rounds judge the decision you made and what it cost.

Describe a time when you had to migrate a service or integrate a new tool. How did you minimize downtime?

Medium · Resume-Based & Architectural Justificati

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. Name the disagreement and how you resolved it with evidence.

Follow-up

  • What would you do differently if you ran that again?
  • How did you know your change caused the improvement?

Tell me about a time you had a technical disagreement with a teammate or architect. How did you resolve it?

Medium · Behavioral & Cultural Alignment

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. Name the disagreement and how you resolved it with evidence.

Follow-up

  • What would you do differently if you ran that again?
  • How did you know your change caused the improvement?

Describe a situation where you had to deliver a project under a tight deadline with incomplete requirements.

Medium · Behavioral & Cultural Alignment

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. Name the disagreement and how you resolved it with evidence.

Follow-up

  • What would you do differently if you ran that again?
  • How did you know your change caused the improvement?

How do you handle constructive criticism or feedback on your code during peer reviews?

Medium · Behavioral & Cultural Alignment

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. Name the disagreement and how you resolved it with evidence.

Follow-up

  • What would you do differently if you ran that again?
  • How did you know your change caused the improvement?

Give an example of a time you had to explain a complex technical concept to a non-technical stakeholder.

Medium · Behavioral & Cultural Alignment

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. Name the disagreement and how you resolved it with evidence.

Follow-up

  • What would you do differently if you ran that again?
  • How did you know your change caused the improvement?

Tell me about a time you failed or made a mistake on a project. What did you learn from it?

Medium · Behavioral & Cultural Alignment

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. Name the disagreement and how you resolved it with evidence.

Follow-up

  • What would you do differently if you ran that again?
  • How did you know your change caused the improvement?