At Loft, a Software Engineer is responsible for building the digital infrastructure that powers one of Latin America's most dynamic real estate platforms. Loft aims to simplify the complex, high-friction process of buying, selling, renting, and financing properties. As an engineer, you will work on products that directly impact thousands of buyers, sellers, real estate agents, and financial partners daily, bringing transparency and efficiency to a traditionally opaque market. Your work will span highly complex transactional systems, financial ledgers, real-time pricing engines, and high-performance search platforms. The engineering team operates at a significant scale, requiring robust, fault-tolerant systems that can handle large volumes of transactional data with absolute precision. You will be tasked with solving non-trivial problems around data consistency, distributed systems, and real-time processing, ensuring that the platform remains highly reliable as the business continues to scale. Ultimately, engineering at Loft is about ownership and product impact. You will not just write code; you will design architectures, collaborate with cross-functional product teams, and make technical decisions that directly influence the company's strategic direction. It is a high-growth environment that demands both technical rigor and a strong product-oriented mindset.
Initial Screening Call
reportedA call with an Engineering Manager or Recruiter to discuss your background, career goals, and team challenges.
What to demonstrate
- A call with an Engineering Manager or Recruiter to discuss your background, career goals, and team challenges
- Depth in System Design
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.
Automated Coding Assessment
reportedCompletion of a coding assessment on a platform like Codility to verify core algorithmic skills.
What to demonstrate
- Completion of a coding assessment on a platform like Codility to verify core algorithmic skills
- Depth in System Design
How to prepare
- Answer aloud and timed: Design an efficient data structure to store and query real estate transactions within a specific price range and geographical boundary.
- Answer aloud and timed: Given an array of historical property price changes, find the maximum profit a real estate investor could make with a single buy-and-sell transaction.
Coding Skills Round
reportedFirst technical round focusing on coding skills, conducted by a pair of Loft engineers.
What to demonstrate
- First technical round focusing on coding skills, conducted by a pair of Loft engineers
- Depth in System Design
How to prepare
- Answer aloud and timed: How would you design a class structure for a property booking system that supports different payment rules, cancellation policies, and user roles?
- Answer aloud and timed: Sketch a class diagram for an automated notification service that dispatches alerts (email, SMS, push) based on user preferences and system events.
Code Design Round
reportedSecond technical round assessing code design, also conducted by a pair of Loft engineers.
What to demonstrate
- Second technical round assessing code design, also conducted by a pair of Loft engineers
- Depth in System Design
How to prepare
- Answer aloud and timed: Explain how you would refactor a monolithic, tightly coupled codebase using SOLID principles to make it more testable and modular.
- Answer aloud and timed: Walk through how you would implement Test-Driven Development (TDD) to build a currency converter utility for international real estate transactions.
System Architecture Round
reportedFinal technical round evaluating system architecture, conducted by a pair of Loft engineers.
What to demonstrate
- Final technical round evaluating system architecture, conducted by a pair of Loft engineers
- Depth in System Design
How to prepare
- Answer aloud and timed: Design a high-level architecture for a real-time property search engine that handles millions of daily queries and updates listing data near-instantaneously.
- Answer aloud and timed: How would you transition a monolithic real estate transaction system into a microservices-based architecture without causing downtime?
Behavioral Rounds
reportedDeep-dive conversation with the People (HR) team followed by a strategic discussion with an Engineering Director or Manager.
What to demonstrate
- Deep-dive conversation with the People (HR) team followed by a strategic discussion with an Engineering Director or Manager
- Depth in System Design
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 behavioral rounds above and write down what you would ask to confirm before it.
PracHub editorial advice for the preparation topics above.
Think Out Loud
Throughout the technical interviews, continuous communication is key. Explain your thought process, state your assumptions, and discuss trade-offs before you start coding or drawing diagrams. This allows the interviewers to guide you if you go off track.
Focus on Simplicity
Avoid the temptation to over-engineer your solutions. Start with a simple, working solution, and then discuss how you would optimize or scale it. Interviewers prefer a clean, functional basic design over an incomplete, overly complex one.
Brush Up on Domain-Driven Design (DDD)
Loft heavily utilizes DDD concepts to manage their complex real estate domains. Being able to speak comfortably about entities, value objects, aggregates, and bounded contexts will immediately set you apart.
Be Prepared for Peer Review
Because Loft conducts interviews in pairs, you will have two engineers evaluating you in each technical round. Do not let this intimidate you; they are there to collaborate, reduce bias, and ensure a fair assessment. Treat them as peers in a design session.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
Implement an algorithm to find the shortest path in a grid representing a real estate map with blocked and ope
Implement an algorithm to find the shortest path in a grid representing a real estate map with blocked and open pathways.
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?
Write a function to detect duplicate property listings based on varying string attributes and similarity thres
Write a function to detect duplicate property listings based on varying string attributes and similarity thresholds.
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?
Given an array of historical property price changes, find the maximum profit a real estate investor could make
Given an array of historical property price changes, find the maximum profit a real estate investor could make with a single buy-and-sell transaction.
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?
Sketch a class diagram for an automated notification service that dispatches alerts (email, SMS, push) based o
Sketch a class diagram for an automated notification service that dispatches alerts (email, SMS, push) based on user preferences and system events.
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?
Denormalise tenant onto revisions and backfill it live
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
- 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.
- 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.
- 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.
- 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?
Hold a per-tenant active cap against concurrent creates
A tenant on the standard plan may hold at most 50 resources with status='active'. The create handler runs SELECT count(*) FROM resource WHERE tenant_id = $1 AND status = 'active', compares to 50, then inserts. Two creates arrive 3 ms apart on different instances and the tenant lands at 51. Name the anomaly, say whether PostgreSQL 16 READ COMMITTED or REPEATABLE READ prevents it and why, then give an implementation that holds the cap at READ COMMITTED with the exact statements. Finally, say what changes when the cap is 'at most one running export per tenant' on job_run.
Approach
- Name it: write skew. The two transactions read an overlapping set and write disjoint rows, so there is no row-level conflict for the engine to detect and each commit is individually legal.
- Rule out the levels precisely. READ COMMITTED takes a fresh snapshot per statement and takes no lock on the counted rows, so both see 49. PostgreSQL's REPEATABLE READ is snapshot isolation: it removes non-repeatable reads and phantoms within the snapshot but still admits write skew, because the anomaly is not a re-read of a changed row, it is a read of a set that a concurrent transaction invalidates. Only SERIALIZABLE closes it, by tracking the read dependency and aborting one transaction with SQLSTATE 40001 — a guarantee that exists only if the application re-runs the whole transaction from the read.
- Convert the set predicate into a single-row conflict: keep tenant.active_resource_count and run UPDATE tenant SET active_resource_count = active_resource_count + 1 WHERE tenant_id = $1 AND active_resource_count < 50 in the same transaction as the INSERT. Zero affected rows is the cap, returned as 409. The row lock serialises the decision at any isolation level, and contention is bounded to one tenant's row — which is also the fair-scheduling unit, unlike a global counter that would convoy every tenant behind one row.
- State the cost you just took on: a counter is a second source of truth that can drift, so every path that changes status must adjust it inside the same transaction, and a periodic reconciliation has to exist, with resource_revision as the authority for what the count should have been.
Follow-up
- A resource moves from archived back to active. Which statements change, and what breaks if the counter update and the status change land in different transactions?
- The cap becomes plan-dependent and a plan can change mid-month. Where does the number 50 live, and who reads it?
Design an efficient data structure to store and query real estate transactions within a specific price range a
Design an efficient data structure to store and query real estate transactions within a specific price range and geographical boundary.
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?
How would you design a class structure for a property booking system that supports different payment rules, ca
How would you design a class structure for a property booking system that supports different payment rules, cancellation policies, and user roles?
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?
Explain how you would refactor a monolithic, tightly coupled codebase using SOLID principles to make it more t
Explain how you would refactor a monolithic, tightly coupled codebase using SOLID principles to make it more testable and modular.
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- Work from the requirement backwards to the design.
Follow-up
- What assumption would you test first?
- How would you know your answer was wrong?
Walk through how you would implement Test-Driven Development (TDD) to build a currency converter utility for i
Walk through how you would implement Test-Driven Development (TDD) to build a currency converter utility for international real estate transactions.
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- Work from the requirement backwards to the design.
Follow-up
- What assumption would you test first?
- How would you know your answer was wrong?
Design a high-level architecture for a real-time property search engine that handles millions of daily queries
Design a high-level architecture for a real-time property search engine that handles millions of daily queries and updates listing data near-instantaneously.
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?
How would you transition a monolithic real estate transaction system into a microservices-based architecture w
How would you transition a monolithic real estate transaction system into a microservices-based architecture without causing downtime?
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?
Design a distributed ledger system for managing financial transactions between buyers, sellers, and banks, ens
Design a distributed ledger system for managing financial transactions between buyers, sellers, and banks, ensuring strict eventual consistency.
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?
Explain how you would apply Domain-Driven Design (DDD) principles to model the complex lifecycle of a real est
Explain how you would apply Domain-Driven Design (DDD) principles to model the complex lifecycle of a real estate sale from listing to deed transfer.
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?
Exports duplicate a row range about once a week
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
- 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.
- 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.
- 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.
- 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?
Built from the rounds and topics Loft candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the Loft loop
- Write out the reported sequence: Initial Screening Call, Automated Coding Assessment, Coding Skills Round, Code Design Round, System Architecture Round, Behavioral Rounds.
- 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 6 reported rounds, with the weakest marked.
02Work System Design
- Spend the session on System Design, which Loft candidates report being tested on.
- Write one worked example in System Design and time yourself on it.
Deliverable: One timed worked example in System Design.
03Work Code Design
- Spend the session on Code Design, which Loft candidates report being tested on.
- Write one worked example in Code Design and time yourself on it.
Deliverable: One timed worked example in Code Design.
04Work Coding Skills
- Spend the session on Coding Skills, which Loft candidates report being tested on.
- Write one worked example in Coding Skills and time yourself on it.
Deliverable: One timed worked example in Coding Skills.
05Answer out loud: Coding & Algorithmic Problem Solving
- Answer aloud, timed: Implement an algorithm to find the shortest path in a grid representing a real estate map with blocked and open pathways.
- Answer aloud, timed: Write a function to detect duplicate property listings based on varying string attributes and similarity thresholds.
Deliverable: Spoken answers to 2 reported Coding & Algorithmic Problem Solving question(s), under time.
06Answer out loud: Code Design & Object-Oriented Principles
- Answer aloud, timed: How would you design a class structure for a property booking system that supports different payment rules, cancellation policies, and user roles?
- Answer aloud, timed: Sketch a class diagram for an automated notification service that dispatches alerts (email, SMS, push) based on user preferences and system events.
Deliverable: Spoken answers to 2 reported Code Design & Object-Oriented Principles question(s), under time.
07Answer out loud: System Architecture & Design
- Answer aloud, timed: Design a high-level architecture for a real-time property search engine that handles millions of daily queries and updates listing data near-instantaneously.
- Answer aloud, timed: How would you transition a monolithic real estate transaction system into a microservices-based architecture without causing downtime?
Deliverable: Spoken answers to 2 reported System Architecture & Design 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.
Tell me about a time when you had a strong technical disagreement with a peer or manager. How did you resolve
Tell me about a time when you had a strong technical disagreement with a peer or manager. How did you resolve it, and what was the outcome?
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 ship a feature with incomplete requirements or high ambiguity. How did y
Describe a situation where you had to ship a feature with incomplete requirements or high ambiguity. How did you proceed?
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?
Walk me through a major technical failure or bug you introduced into production. What did you learn, and how d
Walk me through a major technical failure or bug you introduced into production. What did you learn, and how did you prevent it from happening again?
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?
Why do you want to join Loft, and how do you handle the fast-paced, evolving priorities of a high-growth start
Why do you want to join Loft, and how do you handle the fast-paced, evolving priorities of a high-growth startup?
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
Tell me about a time when you had a strong technical disagreement with a peer or manager. How did you resolve it, and what was the outcome?
- 02
Describe a situation where you had to ship a feature with incomplete requirements or high ambiguity. How did you proceed?
- 03
Walk me through a major technical failure or bug you introduced into production. What did you learn, and how did you prevent it from happening again?
- 04
Why do you want to join Loft, and how do you handle the fast-paced, evolving priorities of a high-growth startup?
Can I choose my programming language for the coding interviews?
Yes. Loft allows you to use the programming language you are most comfortable with for the Coding Skills and Code Design rounds. They value problem-solving ability, clean code practices, and logical structuring over language-specific trivia.
Loft Software Engineer candidate reports ↗How deep do I need to go into microservices and system design?
For mid-to-senior roles, a solid understanding of microservices, database scaling, and distributed systems is essential. You should be familiar with common patterns like event sourcing, CQRS, and the Saga pattern, and be able to explain the trade-offs of using them.
Loft Software Engineer candidate reports ↗What is the typical timeline for the interview process?
The entire process usually takes between 2 to 3 weeks from the initial application to the final offer. The technical rounds are often grouped together into a single afternoon to expedite the evaluation process.
Loft Software Engineer candidate reports ↗Does Loft offer remote work opportunities?
Yes. Loft supports remote work for engineering positions, allowing you to work from various locations in Brazil or internationally, depending on the specific contract and team requirements.
Loft Software Engineer candidate reports ↗How should I prepare for the Code Design round?
Focus on reviewing SOLID principles, common design patterns, and low-level system modeling. Practicing class diagrams and understanding how to decouple business logic from external frameworks will help you succeed in this round.
Loft Software Engineer candidate reports ↗What topics does Loft test in interviews?
Loft interviews most often cover Stakeholder Communication, Product Management (PM) Fundamentals, Machine Learning, System Design, and Product Design. The exact emphasis depends on the specific role you apply for.
Loft 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.
- 01Loft 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
Explore related engineering environments and compare the preparation focus.
Discord Software Engineer Interview Guide
Database practice for Discord candidates: how an index changes a query plan, and which anomalies survive a given isolation level, since read committed still permits non-repeatable reads.
Rystad Energy Software Engineer Interview Guide
Prepare for Rystad Energy software interviews with worked Python validation, OOP and decorator examples, plus an ingestion case and practical checks.
Zwift Software Engineer Interview Guide
What Zwift asks Software Engineer candidates, from reported rounds and questions.
Zumper Software Engineer Interview Guide
What Zumper asks Software Engineer candidates, from reported rounds and questions.