Td bank · Software Engineer
Updated · 2026-10-02

Td bank Software Engineer
Interview Guide

THE 60-SECOND BRIEF

As a Software Engineer at Td bank, you are at the intersection of high-scale financial technology and customer-centric innovation. This role is critical to the bank’s digital evolution, requiring you to bridge the gap between complex enterprise infrastructure and the seamless, secure banking experiences that millions of customers rely on daily. You will be responsible for designing, developing, and maintaining robust systems that adhere to the highest standards of reliability and security. Your work will span the full development lifecycle, from participating in architectural design and system modeling to automating build, test, and release processes. Whether you are working on core banking platforms, customer-facing applications, or internal engineering tools, you will be expected to maintain a "build it, break it, fix it" mentality.

This guide is scoped to a Software Engineer candidate at Td bank.

Td bank candidates report 5 rounds over 4-6 weeks. The stages below are what candidates describe, not a published process.

System DesignSoftware ArchitecturePython

22 min read

Browse Software Engineer questions

See the practice prompts

16Practice promptsAcross five skill areas

As a Software Engineer at Td bank, you are at the intersection of high-scale financial technology and customer-centric innovation. This role is critical to the bank’s digital evolution, requiring you to bridge the gap between complex enterprise infrastructure and the seamless, secure banking experiences that millions of customers rely on daily. You will be responsible for designing, developing, and maintaining robust systems that adhere to the highest standards of reliability and security. Your work will span the full development lifecycle, from participating in architectural design and system modeling to automating build, test, and release processes. Whether you are working on core banking platforms, customer-facing applications, or internal engineering tools, you will be expected to maintain a "build it, break it, fix it" mentality. This position offers the unique challenge of operating within a highly regulated, large-scale environment while driving modern engineering practices like automation, cloud integration, and proactive defect prevention.

01

Recruiter Screen

reported

Initial screening call with a recruiter to assess your background and fit for the role.

What to demonstrate

  • Initial screening call with a recruiter to assess your background and fit for the role
  • 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.
Td bank Software Engineer candidate reports ↗
02

Technical Phone Call

reported

A technical discussion over the phone to evaluate your technical competency.

What to demonstrate

  • A technical discussion over the phone to evaluate your technical competency
  • Depth in System Design

How to prepare

  • Answer aloud and timed: Explain your approach to data modeling and process mapping for a complex system.
  • Answer aloud and timed: What are the most common challenges you face when conducting code reviews, and how do you ensure quality standards?
Td bank Software Engineer candidate reports ↗
03

Technical Quizzes

reported

Multiple rounds of technical quizzes to assess your knowledge and skills.

What to demonstrate

  • Multiple rounds of technical quizzes to assess your knowledge and skills
  • Depth in System Design

How to prepare

  • Answer aloud and timed: Can you explain how you would approach a Salesforce-specific development task?
  • Answer aloud and timed: Tell us about a technical project on your resume—what were the primary challenges and how did you overcome them?
Td bank Software Engineer candidate reports ↗
04

Resume Review

reported

Review of your resume to verify your qualifications and experiences.

What to demonstrate

  • Review of your resume to verify your qualifications and experiences
  • 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.
Td bank Software Engineer candidate reports ↗
05

Behavioral Interviews

reported

Interviews with hiring managers and lead engineers focusing on cultural fit and teamwork.

What to demonstrate

  • Interviews with hiring managers and lead engineers focusing on cultural fit and teamwork
  • 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 interviews above and write down what you would ask to confirm before it.
Td bank Software Engineer candidate reports ↗

PracHub editorial advice for the preparation topics above.

01

Understand the Business

Research Td bank's recent digital initiatives. Being able to connect your technical work to the bank's goals demonstrates high-level thinking.

02

Prepare for Ambiguity

In technical interviews, if a question seems broad, ask clarifying questions before diving into a solution. This shows you are a thoughtful engineer.

03

Focus on Documentation

The role requires significant documentation. Highlight any experience you have in creating technical specs or design documents.

04

Be Ready for a "Deep Dive

If you mention a project on your resume, be prepared to answer deep-dive questions about the architecture, the challenges, and the specific technology choices you made.

Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.

9 technical prompts0 include a worked solution

Archive a resource graph without breaking live references or recursing

medium
graph traversaltopological ordertenant 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?

Collapse a redelivered event batch into per-aggregate high-water marks

easy
hashingat-least-onceaggregation

You drain a batch of up to 5,000,000 events, each (aggregate_id BIGINT, aggregate_version INT, event_type, payload). The log guarantees order within one aggregate only; the batch merges 64 partitions, and a relay failover has redelivered a range, so an older version for an aggregate can appear after a newer one. Given a map of last_applied_version per aggregate, produce the events worth applying, at most one per (aggregate_id, version), plus the count discarded. Target O(n) time. State the memory for 2,000,000 distinct aggregates and what you do when it does not fit.

Approach
  1. One pass, one hash map from aggregate_id to the highest version kept, and a discard counter. An event whose version is at or below last_applied_version for its aggregate is dropped without further work, which is the whole reason the event carries its version rather than a delta. O(n) expected time, O(d) space in distinct aggregates.
  2. Keep the maximum, never the last occurrence. The redelivered range means the final appearance of an aggregate in the batch can be an older version than one seen earlier in the same batch, so last-wins applies stale state over newer state and the projection regresses with no error anywhere.
  3. Cost the memory instead of calling it large: an 8-byte key plus a 4-byte version is 12 bytes of payload, and an open-addressed table held at a 0.7 load factor costs roughly 17 bytes per entry before per-slot metadata, so 2,000,000 aggregates is tens of megabytes in a native layout and several times that in a runtime that boxes both key and value.
  4. If the distinct set exceeds memory, partition on hash(aggregate_id) mod P and reduce each partition independently. Every event for one aggregate hashes to the same partition, so the per-partition result is exact and the merge is concatenation rather than a second reduction.
Follow-up
  • The payload is a patch rather than a snapshot, so applying only the highest version loses the intermediate changes. What changes in your reduction?
  • How do you detect that version 7 arrived while version 6 was never delivered, and what should the consumer do about the gap?

Diff a projection against the primary without per-row point reads

hard
reconciliationrange hashingthrottling

The listing projection has drifted and some rows show a stale version. The primary holds 40,000,000 resource rows across 12,000 tenants while serving 1,200 writes and 14,000 reads per second. The obvious repair, reading each resource row and comparing its version against the projection, is correct and would eventually finish. Explain precisely why it is unacceptable here, then give a diff that finds the differing rows, state its complexity, and make it safe to run against a live primary. Replication lag is usually under 100 ms and is not bounded.

Approach
  1. Quantify the naive cost rather than calling it slow: 40,000,000 point reads at even 0.5 ms each is over five hours serialised, and the only lever is concurrency, which is exactly what you cannot spend. The primary's pool is sized for the write path, and 40,000,000 random reads evict the buffer cache that sustains the 85 percent cache hit rate, so the audit degrades the system it is auditing.
  2. Replace random access with one ordered pass per side. Both sides can be read in (tenant_id, resource_id) order, which is a sequential scan on each and a merge join in O(n) time and O(1) memory. For a dense diff that is the whole answer, and it reads the primary once instead of 40,000,000 times.
  3. For the expected sparse case, compare range hashes instead of rows: partition the key space, compute per range an order-independent aggregate over hash(resource_id, version), compare aggregates, and descend only into ranges that differ. With d differing rows and branching factor B, at most d ranges mismatch per level, so the drill-down examines O(d log_B(n/d)) ranges and reads full rows only in mismatching leaves.
  4. Aggregate with a sum modulo 2^64 or a multiset hash, never XOR. XOR is order-independent but self-cancelling, so two rows wrong in the same way, or a row duplicated on one side, leave the range aggregate matching and the range is declared clean.
Follow-up
  • The diff reports 900 stale rows. How do you decide between patching those rows and rebuilding the projection from resource_revision?
  • Same job, but the projection lives in a search index that cannot be scanned in key order. What changes?

Built from the rounds and topics Td bank candidates report.

Small steps. Visible outcomes.0 / 7 completed
ONE WEEK · YOUR PACE

Prepare, practise & reflect

One practical outcome each day. Spend longer where you need it.

0 / 7 done
01Map the Td bank loop
  • Write out the reported sequence: Recruiter Screen, Technical Phone Call, Technical Quizzes, Resume Review, Behavioral Interviews.
  • 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 5 reported rounds, with the weakest marked.

02Work System Design
  • Spend the session on System Design, which Td bank 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 Software Architecture
  • Spend the session on Software Architecture, which Td bank candidates report being tested on.
  • Write one worked example in Software Architecture and time yourself on it.

Deliverable: One timed worked example in Software Architecture.

04Work Python
  • Spend the session on Python, which Td bank candidates report being tested on.
  • Write one worked example in Python and time yourself on it.

Deliverable: One timed worked example in Python.

05Answer out loud: Technical and Domain Knowledge
  • Answer aloud, timed: Describe your experience with object-oriented programming in a professional setting.
  • Answer aloud, timed: What is the difference between various data structures and when would you choose one over another for a specific task?

Deliverable: Spoken answers to 2 reported Technical and Domain Knowledge question(s), under time.

06Answer out loud: Behavioral and Scenario-Based
  • Answer aloud, timed: Tell us about a technical project on your resume—what were the primary challenges and how did you overcome them?
  • Answer aloud, timed: Describe a time you had to collaborate with a cross-functional team to meet a deadline.

Deliverable: Spoken answers to 2 reported Behavioral and Scenario-Based question(s), under time.

07Dry run for Td bank
  • Run one full mock under time, then write down the two questions you most want to ask your interviewers.

Deliverable: A completed timed mock and two questions to ask.

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.

Describe your experience with object-oriented programming in a professional setting.

medium
Technical and Domain Knowledge

Describe your experience with object-oriented programming in a professional setting.

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?

What are the most common challenges you face when conducting code reviews, and how do you ensure quality stand

medium
Technical and Domain Knowledge

What are the most common challenges you face when conducting code reviews, and how do you ensure quality standards?

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 us about a technical project on your resume—what were the primary challenges and how did you overcome the

medium
Behavioral and Scenario-Based

Tell us about a technical project on your resume—what were the primary challenges and how did you overcome them?

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 time you had to collaborate with a cross-functional team to meet a deadline.

medium
Behavioral and Scenario-Based

Describe a time you had to collaborate with a cross-functional team to meet a deadline.

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 manage your time when balancing multiple development tasks or operational support requirements?

medium
Behavioral and Scenario-Based

How do you manage your time when balancing multiple development tasks or operational support requirements?

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?

What are your professional goals for the next few years, and how does this role align with them?

medium
Behavioral and Scenario-Based

What are your professional goals for the next few years, and how does this role align with them?

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?

Are you comfortable working in an environment that may occasionally require overtime to meet project milestone

medium
Behavioral and Scenario-Based

Are you comfortable working in an environment that may occasionally require overtime to meet project milestones?

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?
  • 01

    Describe your experience with object-oriented programming in a professional setting.

  • 02

    What are the most common challenges you face when conducting code reviews, and how do you ensure quality standards?

  • 03

    Tell us about a technical project on your resume—what were the primary challenges and how did you overcome them?

  • 04

    Describe a time you had to collaborate with a cross-functional team to meet a deadline.

PracHub preparation framework ↗
How difficult are the technical interviews?

The difficulty is generally rated as average. The questions focus on core competencies rather than obscure trivia, but you should be prepared to explain the "why" behind your technical decisions.

Td bank Software Engineer candidate reports ↗
How long does the entire process take?

It can vary significantly. While some candidates report a process lasting only a few days, others may experience a 2-3 month timeline due to background checks and multiple interview rounds.

Td bank Software Engineer candidate reports ↗
What is the best way to prepare for the behavioral questions?

Use the STAR method (Situation, Task, Action, Result) to structure your answers. This keeps your stories concise and ensures you highlight your specific contributions.

Td bank Software Engineer candidate reports ↗
Is there a specific focus on coding languages?

While the bank uses a variety of stacks, focus on the languages listed in your specific job posting. Be ready to discuss the trade-offs of the languages you use most frequently.

Td bank Software Engineer candidate reports ↗
What topics does Td bank test in interviews?

Td bank interviews most often cover Python, Behavioral Interviewing, SQL, Mathematics (General), and Problem Solving. The exact emphasis depends on the specific role you apply for.

Td bank 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.