As a Software Engineer at ITJ, you are a critical architect of digital transformation. You are not merely writing code; you are building scalable, high-impact solutions that bridge the gap between complex business requirements and cutting-edge technology. Your work directly influences the efficiency and technological maturity of the projects you support, often requiring you to operate in a fast-paced environment where precision and adaptability are paramount. This role requires a blend of deep technical proficiency and the ability to thrive in a collaborative, cross-functional setting. You will engage with diverse teams, including product managers and technical leads, to solve multifaceted problems. Because ITJ values both technical excellence and strong communication, you must be capable of translating technical constraints into strategic business value, ensuring that the software you deliver is robust, maintainable, and aligned with the company's broader objectives.
Recruiter Screen
reportedInitial screening focusing on your background, motivations, and English proficiency.
What to demonstrate
- Initial screening focusing on your background, motivations, and English proficiency
- Depth in Programming Assessments
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 Assessments
reportedInvolves coding challenges to evaluate technical skills.
What to demonstrate
- Involves coding challenges to evaluate technical skills
- Depth in Programming Assessments
How to prepare
- Answer aloud and timed: How do you handle edge cases when designing a new feature?
- Answer aloud and timed: Can you explain the trade-offs between using different data structures for a specific problem?
Interviews with Leads
reportedInterviews with technical leads or management to assess fit and skills.
What to demonstrate
- Interviews with technical leads or management to assess fit and skills
- Depth in Programming Assessments
How to prepare
- Answer aloud and timed: What is your process for performing code reviews to ensure high quality and security?
- Answer aloud and timed: Tell me about a time you had a disagreement with a team member; how did you resolve it?
PracHub editorial advice for the preparation topics above.
Communicate your thought process
Even if you don't know the exact answer, explain how you would find it.
Research the company
Understand the types of services ITJ provides to better align your answers with their business goals.
Prepare your own questions
Always have 2–3 insightful questions ready for the interviewer to show your interest.
Master the fundamentals
Many candidates focus too much on frameworks and forget the underlying data structures.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
How do you approach optimizing a function that is experiencing latency issues?
How do you approach optimizing a function that is experiencing latency issues?
Approach
- Restate the input: its shape, its size, and what is guaranteed about it.
- Name the brute-force solution and its complexity before improving on it.
- Choose the data structure from the access pattern, not from familiarity.
- State the target complexity and say which constraint rules the naive version out.
Follow-up
- How does this change if the input no longer fits in memory?
- What is the worst case, and how likely is it on real data?
Can you explain the trade-offs between using different data structures for a specific problem?
Can you explain the trade-offs between using different data structures for a specific problem?
Approach
- Restate the input: its shape, its size, and what is guaranteed about it.
- Name the brute-force solution and its complexity before improving on it.
- Choose the data structure from the access pattern, not from familiarity.
- State the target complexity and say which constraint rules the naive version out.
Follow-up
- How does this change if the input no longer fits in memory?
- What is the worst case, and how likely is it on real data?
Could you walk me through your most challenging technical project to date?
Could you walk me through your most challenging technical project to date?
Approach
- Say what the runtime actually does before reasoning about the code.
- Name what is shared across threads and what owns each piece of state.
- Identify the window where an invariant is briefly untrue.
- 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?
Why do you want to work at ITJ specifically?
Why do you want to work at ITJ specifically?
Approach
- Say what the runtime actually does before reasoning about the code.
- Name what is shared across threads and what owns each piece of state.
- Identify the window where an invariant is briefly untrue.
- 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?
Keep soft-deleted accounts from blocking re-registration
app_user holds user_id, tenant_id, email CITEXT, password_hash (NULL for SSO principals), email_verified_at, auth_version, status ('invited','active','suspended','deactivated'), created_at, updated_at, deleted_at. Two live accounts for one address inside a tenant must be impossible, but an address freed by a soft delete must be reusable, and the same tenant may delete and re-register it repeatedly. Write the uniqueness DDL for PostgreSQL 16, then the equivalent for MySQL 8 where partial indexes do not exist, and say what each permits once three deleted rows already hold that address.
Approach
- Start from what is actually unique: not (tenant_id, email), but (tenant_id, email) among live rows. PostgreSQL says that directly — CREATE UNIQUE INDEX app_user_live_email ON app_user (tenant_id, email) WHERE deleted_at IS NULL. A full constraint over the same two columns burns the address permanently the first time someone deletes an account.
- Keep case-insensitivity in the type or the index, never in the application: CITEXT as given, or UNIQUE (tenant_id, lower(email)) as an expression index where the extension is unavailable. A case-sensitive unique column is exactly how two accounts for one human appear.
- For MySQL 8 the predicate has to move inside the key: add a discriminator column that is a constant 0 while the row is live and is set to user_id on delete, with UNIQUE (tenant_id, email, deleted_marker). Live rows share the constant and still collide; deleted rows differ from each other and stop colliding.
- State the NULL variant and its dependency: leaving the marker NULL for deleted rows also works, because a unique index treats NULLs as distinct — true in MySQL, and true in PostgreSQL only under the default NULLS DISTINCT, which PostgreSQL 15 lets you reverse. Check the polarity against the three existing deleted rows: constant-on-live is what preserves the collision you want, and reversing it silently admits duplicate live accounts.
Follow-up
- A deleted account re-registers with the same address the next day. Do the old resource rows follow the new user_id, and how does the API keep the two principals apart?
- How do you honour an erasure request while resource_revision.actor_user_id still references this table?
Replace offset paging on the resource feed with keyset
resource holds resource_id, tenant_id, owner_user_id, title, body_ref, version, status ('draft','active','archived','deleted'), created_at, updated_at, deleted_at, with an index on (tenant_id, status, updated_at DESC, resource_id DESC). The listing endpoint returns active resources for one tenant, newest update first, 50 per page, today with LIMIT 50 OFFSET n. Tenants reach page 400 and rows are created while they read. Write the keyset query, define what the cursor carries and how it is encoded, and say which part of the index each predicate uses. Assume PostgreSQL 16.
Approach
- Name the two failures separately. OFFSET 20000 makes the server produce and discard 20,000 rows, so page cost grows with depth rather than with page size. Independently, any write that changes how many rows sort above the offset moves the window between two fetches, and the direction decides which anomaly you get: an insert lands at the head of updated_at DESC and pushes already-returned rows down past the boundary, so they are returned a second time; a delete above the offset, or a row whose updated_at is bumped above the cursor, pulls rows up and one is never returned at all. Nothing in the response reveals either.
- Write the seek: WHERE tenant_id = $1 AND status = 'active' AND (updated_at, resource_id) < ($2, $3) ORDER BY updated_at DESC, resource_id DESC LIMIT 50. The row-value comparison is one index range rather than a disjunction, and both columns are NOT NULL, which is what makes that comparison well defined.
- Map each predicate onto the index: tenant_id and status are equality on the leading columns, (updated_at, resource_id) is the range, and the ORDER BY matches the index order so no Sort node appears and the scan stops after 50 rows. The DESC in the definition only matters for mixed directions — a plain ascending btree on the same columns is read backwards for this query.
- Put both sort columns in the cursor and nothing the client can tamper with into another tenant: base64 of (updated_at, resource_id), validated server-side, with tenant_id taken from the principal.
Follow-up
- The client asks for 'jump to page 400'. What do you offer instead, and what does the honest version cost?
- Sort order becomes user-selectable across four columns. How many indexes is that, and which would you refuse to add?
How do you ensure clear communication within a remote or distributed team?
How do you ensure clear communication within a remote or distributed team?
Approach
- Fix the scope first: who calls this, how often, and what they do when it fails.
- Name the read and write paths separately; they rarely have the same bottleneck.
- Choose a partition key and say what query it makes expensive.
- 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?
Specify the outbound webhook contract a customer endpoint can verify
Egress delivery sends resource.created, resource.updated and resource.archived to roughly 40k customer endpoints at about 1.5k deliveries/second, with a per-destination concurrency cap of 4 and a 10 second connect-plus-read timeout, at-least-once from the relay. The receiver is code you do not control, often behind a proxy that may re-encode JSON. Specify the payload envelope, how the receiver verifies authenticity and rejects replays, what ordering it may assume, how it deduplicates, which status codes it should return and what each means to us, and the retry, circuit and replay behaviour.
Approach
- Send the fact, not a pointer: event_id, event_type, aggregate_type, aggregate_id, aggregate_version, occurred_at and the payload copied from outbox_event. A receiver told only that resource 42 changed has to call back, and the call back returns a newer state than the event describes - that is precisely how a consumer applies changes out of order while believing it is following them.
- Sign the exact bytes on the wire: HMAC-SHA256 over the timestamp, a separator, and the raw body, in a header, compared in constant time before the body is parsed. Instruct receivers to verify the raw bytes, never a re-serialised copy, since a proxy that reorders keys or changes whitespace invalidates a signature computed over re-encoded JSON. Reject a timestamp outside a tolerance - five minutes is typical - and keep a short seen-set of event_ids, because a capture replayed inside the tolerance still verifies.
- Support key rotation by sending several signature values in one header during the overlap window and publishing that any one that verifies is sufficient. Without that rule a key rotation is a synchronised outage across every destination at once.
- State the guarantee as it actually is: at-least-once and unordered, including within a single aggregate_id. The outbox is ordered per aggregate at the source, but the relay holds up to 4 requests in flight per destination and backs off each retry independently, so a version 6 delivery that needs one retry lands after a version 7 that succeeded on its first attempt. Publishing per-aggregate ordering we do not enforce is worse than publishing none, because a receiver that trusts it overwrites new state with old. Receivers deduplicate on event_id and apply conditionally - UPDATE ... WHERE aggregate_version < :incoming, or the same comparison under a row lock on the aggregate - which discards stale redeliveries and stays correct when two deliveries for one aggregate are processed at the same time. A duplicate and an out-of-order delivery then have the same outcome: no-op.
Follow-up
- A customer insists an event never arrived. What do you check, in order, and which table settles the argument?
- A receiver cannot store a version and asks us to deliver their events in order. What would the relay have to give up to offer that, and what does one failing event then do to the rest of their stream?
Describe a time you had to debug a complex production issue under pressure.
Describe a time you had to debug a complex production issue under pressure.
Approach
- Establish what changed and when, before forming any theory.
- Pick a bisection that eliminates candidates whichever way it turns out.
- Check the instrumentation before believing the symptom.
- Separate the trigger from the cause; the deploy is rarely the bug.
Follow-up
- What would you look at first, and what would it rule out?
- How would you tell a cause from a coincidence here?
Built from the rounds and topics ITJ candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the ITJ loop
- Write out the reported sequence: Recruiter Screen, Technical Assessments, Interviews with Leads.
- 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.
02Work Programming Assessments
- Spend the session on Programming Assessments, which ITJ candidates report being tested on.
- Write one worked example in Programming Assessments and time yourself on it.
Deliverable: One timed worked example in Programming Assessments.
03Work Coding Problem Solving
- Spend the session on Coding Problem Solving, which ITJ candidates report being tested on.
- Write one worked example in Coding Problem Solving and time yourself on it.
Deliverable: One timed worked example in Coding Problem Solving.
04Work Technical Interviewing
- Spend the session on Technical Interviewing, which ITJ candidates report being tested on.
- Write one worked example in Technical Interviewing and time yourself on it.
Deliverable: One timed worked example in Technical Interviewing.
05Answer out loud: Technical Proficiency and Problem Solving
- Answer aloud, timed: How do you approach optimizing a function that is experiencing latency issues?
- Answer aloud, timed: Describe a time you had to debug a complex production issue under pressure.
Deliverable: Spoken answers to 2 reported Technical Proficiency and Problem Solving question(s), under time.
06Answer out loud: Behavioral and Leadership
- Answer aloud, timed: Tell me about a time you had a disagreement with a team member; how did you resolve it?
- Answer aloud, timed: How do you manage your time when working on multiple high-priority tasks?
Deliverable: Spoken answers to 2 reported Behavioral and Leadership question(s), under time.
07Answer out loud: Communication and Language Skills
- Answer aloud, timed: Could you walk me through your most challenging technical project to date?
- Answer aloud, timed: How do you ensure clear communication within a remote or distributed team?
Deliverable: Spoken answers to 2 reported Communication and Language Skills question(s), under time.
Expand any day for tasks and deliverables. Your progress is saved on this device.
Behavioural rounds judge the decision you made and what it cost.
How do you handle edge cases when designing a new feature?
How do you handle edge cases when designing a new feature?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- 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?
What is your process for performing code reviews to ensure high quality and security?
What is your process for performing code reviews to ensure high quality and security?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- 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 disagreement with a team member; how did you resolve it?
Tell me about a time you had a disagreement with a team member; how did you resolve it?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- 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 manage your time when working on multiple high-priority tasks?
How do you manage your time when working on multiple high-priority tasks?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- 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 explain a complex technical concept to a non-technical stakeholder.
Describe a situation where you had to explain a complex technical concept to a non-technical stakeholder.
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- 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?
What motivates you to stay updated with the latest industry trends and technologies?
What motivates you to stay updated with the latest industry trends and technologies?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- 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 adapt to changing requirements in the middle of a project?
How do you adapt to changing requirements in the middle of a project?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- 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?
- 01
How do you handle edge cases when designing a new feature?
- 02
What is your process for performing code reviews to ensure high quality and security?
- 03
Tell me about a time you had a disagreement with a team member; how did you resolve it?
- 04
How do you manage your time when working on multiple high-priority tasks?
How difficult are the technical interviews?
They are of average difficulty, but they require consistent preparation. Focus on core fundamentals rather than obscure library features.
ITJ Software Engineer candidate reports ↗How long does the process take?
The process is generally fast, but it can vary based on scheduling. Expect a few weeks from the initial screen to the final offer.
ITJ Software Engineer candidate reports ↗Is the culture at ITJ very formal?
No, the culture is described as friendly and accessible. However, maintain a high level of professional focus during your interviews.
ITJ Software Engineer candidate reports ↗What topics does ITJ test in interviews?
ITJ interviews most often cover Data Pipeline Development, Mobile Engineering, Programming Assessments, SQL, and Technical Interviewing (coding challenges). The exact emphasis depends on the specific role you apply for.
ITJ Software Engineer candidate reports ↗Sources & methodology 3 sources ↗
No official company page is cited. Rounds and questions come from candidate reports and PracHub editorial material; each source shows the date it was read.
- 01ITJ Software Engineer candidate reports ↗
Company-reported rounds, questions and FAQ.
Candidate reports · Accessed 2026-09-22 - 02PracHub Software Engineer practice ↗
PracHub practice material, not company-reported.
PracHub page · Accessed 2026-09-22 - 03PracHub preparation framework ↗
PracHub preparation guidance.
PracHub page · Accessed 2026-09-22
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