Giga · Software Engineer
Updated · 2026-09-24

Giga Software Engineer
Interview Guide

THE 60-SECOND BRIEF

As a Software Engineer at Giga, you are at the forefront of the generative AI revolution. Giga is building the next generation of customer experience through real-time AI agents capable of understanding complex human emotion and resolving issues at enterprise scale. With significant backing from top-tier investors and a proven track record with major partners like DoorDash, the company is currently at a critical inflection point, moving toward its goal of becoming the go-to AI platform for all enterprise automation.

Most rounds test how you handle an under-specified problem more than what you recall. A wrong first approach you correct out loud is recoverable; a constraint you assumed silently and were never given is the expensive mistake.

Giga candidates report 4 rounds · ≈ 3-5 weeks. The stages below are what candidates describe, not a published process.

Bound blast radius with per-tenant concurrency limitsMake every write idempotent under client retriesBuild at-least-once pipelines with explicit deduplication horizons

34 min read

Practice 14 Software Engineer prompts
2Company bank questionsSnapshot · Sep 26, 2026 PT
14Practice promptsAcross five skill areas
3With worked solutionsIncluded in the practice prompts

As a Software Engineer at Giga, you are at the forefront of the generative AI revolution. Giga is building the next generation of customer experience through real-time AI agents capable of understanding complex human emotion and resolving issues at enterprise scale. With significant backing from top-tier investors and a proven track record with major partners like DoorDash, the company is currently at a critical inflection point, moving toward its goal of becoming the go-to AI platform for all enterprise automation.

This role is designed for engineers who thrive on high ownership and rapid execution. You will contribute directly to Chat and Voice AI products, with the expectation that you will eventually take full ownership of product lines. Because Giga operates in a fast-paced, startup environment, you will have the autonomy to drive technical architecture and influence the company’s strategic direction. If you are passionate about building scalable, high-quality systems that impact millions of users, this role offers a rare opportunity to help build a generational technology company.

01

Recruiter Screen

reported

Half of this call is the part candidates treat as small talk: start date, notice period, work authorisation and its timing, location and time zone, on-call, and the number. Those are what kill offers late, after several engineers have each spent a day. Surfacing a hard constraint now costs you nothing and occasionally buys you something, since a loop compressed to fit a competing deadline can usually only be arranged if it is asked for early. The common failure is deflecting the compensation question twice, then discovering at offer stage that the band never reached your number.

What to demonstrate

  • Whether your hard constraints are compatible with the role before a loop gets booked: earliest start, notice period, what authorisation you hold and when it needs action, days on site, willingness to carry a pager
  • Whether you give a compensation range with something behind it, such as current total compensation or a competing timeline, rather than leaving the band untested
  • Whether your stated timeline is real, since a competing deadline raised now is something scheduling can sometimes work around and the same deadline raised at offer stage usually is not

How to prepare

  • Write each constraint down in one line before the call and state them as facts rather than negotiating them live under a question you were not expecting
  • Set your range from two or three current data points for that level and location, and name the structure you are quoting in, so the number is comparable to the one they are holding
  • If another process is running, say where it stands and by when, and ask directly whether this loop can be scheduled inside that window
PracHub interview research ↗
02

Technical Discussion

reported

The same problem is scored by two different mechanisms depending on the format, and preparing for one does not cover the other. With a person watching, partial progress is visible and a hint is a correction you can absorb; silence is the expensive failure, because nobody can read a half-written function. With an automated grader there is no partial credit for what you were about to do, nobody to ask, and the worked examples in the prompt are the entire specification. Read them as a contract, down to whether an empty result should be an empty list or no output at all.

What to demonstrate

  • In a live session, whether your commentary tracks what your hands are doing, and whether a hint redirects you or gets defended against
  • In an automated one, whether you cover the cases the examples do not show, since the hidden cases are where the score moves
  • Whether you manage the clock on purpose: abandoning an approach that is not converging while there is still time to write something simpler that finishes

How to prepare

  • Have someone hand you a problem and feed you one deliberately wrong hint. Practise testing it against a concrete case instead of accepting or rejecting it on authority.
  • Do one timed run a week in a plain browser editor with autocomplete, linting and your own snippets switched off, which is closer to what these environments give you
  • For the automated format, write the harness before the solution: a main that feeds the worked examples plus an empty and a single-element case and prints expected against actual, so a wrong submission is caught by you first
PracHub interview research ↗
03

Dual-Phase Coding Exercise

reported

Input bounds are the part of the prompt most often skimmed, and they usually contain the answer. They tell you which complexity class is admissible, which narrows the search before you have thought about the problem itself. As a rough planning figure, a compiled language does on the order of 10^8 simple operations per second and an interpreted one roughly an order of magnitude less. So n up to about twenty admits enumerating subsets, a few thousand admits a quadratic pass, and a million admits neither: you need near-linear, or linear with a log factor. If the bounds are missing, ask for them.

What to demonstrate

  • Whether the approach is justified by the stated input size rather than by whichever pattern you recognised first
  • Whether you ask about the properties that change the algorithm: whether the input arrives sorted, whether duplicates occur, whether values are bounded integers, whether it all fits in memory
  • Whether you can name the bottleneck in your own solution and what would remove it, even when you deliberately leave it in place
  • Whether a claimed speedup is real, since memoising a recursion only helps when subproblems genuinely overlap and the state can be keyed cheaply

How to prepare

  • For each algorithm you rely on, write down the largest n it handles in roughly a second, then check two of those figures by timing them in the language you will actually type in
  • For two weeks, write one line naming your target complexity and the bound that justifies it before you write any code, then compare that line with what you ended up submitting
  • Practise the conversion backwards: given a required O(n log n), list the mechanisms that get you there (sorting, a heap, an ordered map, divide and conquer) and choose by what the problem needs to query, not by what you used last
PracHub interview research ↗
04

Onsite Assessment

reported

A day like this is several different games in a row, and the expensive mistake is carrying the previous one into the next room. Coding rewards narrow precision and finishing inside a timer. Design rewards breadth, stated assumptions and naming what you are deliberately not building. Behavioural rewards specificity about people and decisions. Candidates who over-engineer a coding problem they were supposed to finish, or who start sketching class hierarchies before anyone has agreed what the system has to do, are usually still playing the last round. Between rooms, name out loud which game the next one is.

What to demonstrate

  • Whether the coding round ends with something that runs and has been traced against a degenerate input, rather than an extensible design that was never finished
  • Whether a design discussion opens by agreeing on traffic shape, read-to-write ratio and what is allowed to be stale, instead of proceeding from an architecture you arrived with
  • Whether a behavioural answer names a person, a disagreement and what you did about it, rather than describing the system the story happened inside
  • Whether the opening habits still appear late in the day: restating the problem, asking for constraints, saying the plan before typing

How to prepare

  • Book three mocks of different types back to back on one afternoon and ask each interviewer afterwards which round you answered in the wrong mode
  • Write a three-line opening script per round type — coding: restate, name the approach and its cost, then type; design: ask for scale, read-write mix and what must not break; behavioural: name the person, the stakes and the decision — and run it off a card so the switch is mechanical rather than remembered
  • Practise coding with a timer you do not extend, stopping when it stops, so the trained reflex is to finish a correct solution rather than to keep improving one
PracHub interview research ↗

PracHub editorial advice for the preparation topics above.

01

Treating a timed-out write as a failed write

A timeout says the response did not arrive, not that the work did not happen; the server may well have committed and then lost the connection. Retrying a non-idempotent create after a timeout is the standard way to end up with two of something, and those duplicates land precisely when the system is already degraded and least able to absorb them. The discipline is to treat a timeout as unknown: either the write carries an idempotency key so the retry is safe by construction, or the client re-reads authoritative state before deciding what to do, and the interface says unknown rather than showing a failure that invites a second click.

02

Holding money in a floating-point type, or rounding it more than once

Binary floating point cannot represent 0.01 or 0.1 exactly, so sums drift and two code paths that should agree disagree by cents nobody can trace back. The fix is integer minor units or an exact decimal type end to end, with sub-cent rates expressed as scaled integers such as micro-units, because a per-request price genuinely is smaller than a cent. The second half of the trap is rounding position: rounding each line and then summing gives a different total from summing and rounding once, and half-up and half-even diverge systematically across many lines, so rounding must happen at one named place and every downstream reader must carry the rounded value rather than recompute it from quantity and rate.

03

A queue or buffer with no bound

Every producer-consumer boundary needs a capacity and a policy for reaching it: block the producer, shed load, or drop the oldest entry. Unbounded buffering converts a temporary slowdown into memory exhaustion and hides the backpressure signal that would have revealed the consumer was falling behind.

04

Finishing a solution without stating its complexity

Give time and space in the same breath as the code, and define n explicitly when there are two sizes, since n nodes and m edges are not interchangeable. Space is the half that gets skipped: count the auxiliary structures you allocate and the recursion stack at its deepest, not only the answer you hand back.

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

11 technical prompts3 include a worked solution

Build a functional game from scratch using AI-assisted coding tools.

medium
data structures and algorithms

Build a functional game from scratch using AI-assisted coding tools.

Approach
  1. Walk one small example through your approach before writing the whole thing.
  2. Restate the input: its shape, its size, and what is guaranteed about it.
  3. Choose the data structure from the access pattern, not from familiarity.
Follow-up
  • What is the worst case, and how likely is it on real data?
  • How does this change if the input no longer fits in memory?

How do you manage technical debt while maintaining high development ve…

medium
data structures and algorithms

How do you manage technical debt while maintaining high development velocity?

Approach
  1. Restate the input: its shape, its size, and what is guaranteed about it.
  2. Name the brute-force solution and its complexity before improving on it.
  3. Choose the data structure from the access pattern, not from familiarity.
Follow-up
  • How does this change if the input no longer fits in memory?
  • Which test case would catch an off-by-one here?

Extend your existing game implementation by adding features or refacto…

medium
data structures and algorithms

Extend your existing game implementation by adding features or refactoring code without the use of AI.

Approach
  1. Restate the input: its shape, its size, and what is guaranteed about it.
  2. Choose the data structure from the access pattern, not from familiarity.
  3. Name the brute-force solution and its complexity before improving on it.
Follow-up
  • Which test case would catch an off-by-one here?
  • How does this change if the input no longer fits in memory?

Describe your process for debugging a complex issue in a production en…

medium
data structures and algorithms

Describe your process for debugging a complex issue in a production environment.

Approach
  1. Restate the input: its shape, its size, and what is guaranteed about it.
  2. State the target complexity and say which constraint rules the naive version out.
  3. Choose the data structure from the access pattern, not from familiarity.
Follow-up
  • What is the worst case, and how likely is it on real data?
  • Which test case would catch an off-by-one here?

Parse and verify a timestamped multi-signature webhook header

easyWorked solution
parsinghmacconstant-time-comparereplay-protection

An inbound webhook carries a signature header of at most 1 KiB shaped t=<unix seconds>,v1=<64 hex chars>, with up to five v1 values during secret rotation and possibly unknown scheme keys. You hold the raw request body bytes and the currently active signing secrets. Write the parser and the verifier: accept when any active secret reproduces a signature and the timestamp is within a five-minute tolerance in either direction, reject otherwise. Single left-to-right pass over the header, no regular expression. State what is inside the MAC and why.

Approach
  1. Parse in one scan: split on ,, then on the first = only, since a value may itself contain = under a future scheme. Accept t exactly once and treat a second t as a reject rather than last-wins. Push every v1 onto a short list and ignore any other key, so a v2 can be introduced later without breaking this verifier.
  2. Say what is signed: HMAC-SHA256 over the exact byte string <t>.<raw body bytes>, yielding 32 bytes or 64 hex characters. The timestamp sits inside the MAC because otherwise an attacker replays yesterday's body with its still-valid signature and only has to edit the header timestamp.
  3. Hash the bytes as received. Verifying against a re-serialised JSON body is the usual defect: key order, whitespace and number formatting all change the bytes while the parsed objects compare equal, so signatures fail for honest senders and the popular 'fix' is to stop checking.
  4. Compare in constant time over fixed-length digests. Decode the hex to 32 bytes, accumulate acc |= a[i] ^ b[i] across the whole length, and test acc == 0 at the end. Evaluate every candidate without an early exit; at five candidates that is five HMACs over the body, linear in body size and negligible beside the network.
  5. Apply the tolerance as a two-sided bound, rejecting when |now - t| > 300 seconds. A sender whose clock runs ahead of yours is an ordinary case, and an unbounded future timestamp is a free replay window.
  6. Complexity: O(L) over the header producing k candidates, plus k HMACs at O(|body|) each. Space is O(k) beyond the body itself. Do the cheap rejections, including the tolerance check, before any cryptography runs.
Worked solution 15 min
  1. Write the grammar on one line before coding: header := field (',' field)*, field := key '=' value, split on the first = only.
  2. Implement the parser to return {t: int, v1: [hex, ...]}, rejecting a missing t, a duplicate t, any v1 that is not 64 hex characters, and a header over 1 KiB, all before any cryptography runs.
  3. Implement the verifier: for each active secret compute HMAC-SHA256(secret, f'{t}.'.encode() + raw_body), compare it in constant time against each parsed v1, and OR the results with no early exit.
  4. Test with a valid signature; the same body with t moved 400 seconds into the past; the same body with t 400 seconds into the future; a header carrying an unknown v2= alongside a valid v1; and a body re-serialised with different JSON key order.
EXPECTED RESULTThe valid case accepts. Both out-of-tolerance cases reject, including the future one. The unknown `v2` field is ignored and the `v1` still verifies. The re-serialised body fails, which is correct and is exactly why the raw bytes must be retained.
Follow-up
  • The body is 40 MB. What changes about where you verify, and what can you do before the whole body has arrived?
  • A customer reports that signatures fail for exactly the requests whose body contains a non-ASCII character. What is your first hypothesis?
  • How do you rotate the signing secret with no failed deliveries, and how long do both secrets stay live?

Four days sample coding, design, fundamentals and the practical rounds at deliberately shallow depth, which is enough to surface the topics you did not know were in scope. That map, rather than a guess made on day one, decides where the last three days go.

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
01Coding, one pass at shallow depth
  • Solve one problem from each of six families, an array with two pointers, hash counting, binary search, a tree traversal, a graph traversal and one dynamic program, under a hard twenty-minute cap with no extensions, marking each finished, late, or stalled.
  • For every stall, write the exact move you could not make rather than the subject, so the note reads could not turn the recurrence into a loop rather than bad at dynamic programming.
  • Fix nothing today. The value of the pass is the unfixed record.

Deliverable: Six timed attempts marked finished, late or stalled, each stall carrying a named blocking move.

Practice prompt ↗Practice prompt ↗Worked solution ↗
02Design, one pass at shallow depth
  • Spend twenty minutes each on three different shapes, a read-heavy feed, a write-heavy ingest path, and something needing a transaction across two entities, stopping each at requirements, interface and data model.
  • After each, write the first question you could not answer, which is usually a number you could not estimate or a failure mode you had no vocabulary for.
  • Mark which of the three you would be most relieved not to be asked, and treat that as data rather than as a preference.

Deliverable: Three shallow designs, each with the first unanswerable question written at the bottom.

Practice prompt ↗Practice prompt ↗
03Fundamentals and the practical rounds
  • Answer eight short questions in writing at four minutes each, covering the material that fills the gaps between the big rounds: what happens between a URL and a rendered page, what an index costs on write, when a process is preferable to a thread, and what conditions a deadlock requires.
  • Do one thirty-minute practical task of the kind a take-home compresses: read an unfamiliar two-hundred-line file and write what it does, what you would change, and the one thing you remain unsure of.
  • Score every answer fluent, correct but slow, or absent, and keep the absent ones visible.

Deliverable: Eight scored short answers and one written reading of unfamiliar code.

Practice prompt ↗Practice prompt ↗
04The rounds that are about you, and the map
  • Deliver three behavioural answers aloud against a timer, a conflict, a failure you owned, and a decision made without enough information, marking any that ran past three minutes or contained no number.
  • Assemble the map: every marked item from days one to three on a single page, sorted by how likely it is to appear in your loop rather than by how uncomfortable it felt.
  • Choose exactly two areas for the remaining three days and write down what you are deliberately abandoning.

Deliverable: A one-page scored map of the whole surface area with two areas chosen and the rest explicitly abandoned.

Practice prompt ↗Practice prompt ↗Worked solution ↗
05First chosen area, to the depth you skipped
  • Work the higher-ranked area in four focused blocks, choosing items one level above where you stalled rather than repeating what already works.
  • After each block write the rule you extracted in one sentence with its precondition attached, since a rule carrying no precondition is exactly what fails under a variation.
  • Re-attempt the day-one or day-two item that exposed this area and compare against the original timing.

Deliverable: Four worked blocks, a timed re-attempt against the original, and three one-sentence rules with preconditions.

Practice prompt ↗Practice prompt ↗
06Second chosen area, where the gap is coverage rather than speed
  • Treat the second area differently from the first. Day five drilled something you could already half-do; this one is usually a topic you had simply never met, so build one worked reference example end to end and keep it, rather than attempting six problems badly.
  • Write down the vocabulary you were missing on day two or three, five terms at most, each with the one sentence that makes it usable in an answer rather than the textbook definition.
  • Redo the shallow attempt that exposed this area and note whether you now fail later in the problem, because moving the failure point is the realistic gain from a single day and is worth more than a score that did not change.

Deliverable: One worked reference example for the newly covered area, a five-term vocabulary list, and a note on where the failure point moved.

Practice prompt ↗Practice prompt ↗
07Reassemble the loop
  • Sit two rounds back to back with no gap, ordering them so the area you chose second comes last, because the map was built from rested, isolated attempts and the loop will reach your weaker area when you are already spent.
  • Write where the second round suffered from the first, which is normally the point at which structure collapses into narration.
  • Reduce the week to one page holding only the rules you can state without reading them.

Deliverable: Mock notes on cross-round carryover plus a one-page card of rules you can recite from memory.

Practice prompt ↗Practice prompt ↗Worked solution ↗

Expand any day for tasks and deliverables. Your progress is saved on this device.

Counting review comments or mentees proves nothing. The useful version is a specific change you approved with a reservation you stated, or one you blocked and the delay that cost. Say which standard you were holding and why it was worth the friction. A mentoring story needs the thing the other person can now do without you.

Describe a time you took full ownership of a project from ideation to …

medium
behavioural and engineering judgement

Describe a time you took full ownership of a project from ideation to launch.

Approach
  1. Close with what you would do differently, concretely.
  2. Give the blast radius: what could have broken, and what you measured.
  3. Pick a story where you made the decision, not one where you watched it.
Follow-up
  • What did you decide not to do, and why?
  • What would you do differently if you ran that again?

How do you handle ambiguity when the requirements for a feature are no…

medium
behavioural and engineering judgement

How do you handle ambiguity when the requirements for a feature are not fully defined?

Approach
  1. Give the blast radius: what could have broken, and what you measured.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Pick a story where you made the decision, not one where you watched it.
Follow-up
  • What did you decide not to do, and why?
  • What would you do differently if you ran that again?

Ship metered billing with a named deduplication horizon

medium
technical debtdeduplicationdeadline pressuredetectors

Metered billing must be on in three weeks. usage_event is partitioned daily, so its unique index must include the partition key and deduplicates only within a day: a producer retry that crosses midnight, or a replay run a week later, gets through. A cross-partition dedup store is two weeks you do not have. Describe shipping with debt you named in advance: what you shipped, what you wrote down, the detector you added, the trigger and date for paying it off, and what you would have refused to ship under the same pressure.

Approach
  1. Show you can separate the two kinds of debt, because that distinction is what the question actually probes. Debt that costs engineering time later is shippable on a deadline. Debt that silently corrupts a number a customer gets charged for is not shippable unless the corruption is detectable, and detectability is the whole negotiation.
  2. Make the exposure narrow and measured rather than gestural. The hole is duplicates whose occurrences straddle a UTC day boundary, plus any replay older than partition retention. Measure it before arguing about it: how often an idempotency_key recurs at all, and the distribution of the gap between first and last occurrence. If the ninety-ninth percentile of that gap is four minutes, the residual risk is a small band around midnight and you can say so numerically.
  3. Add the detector before the feature, not after. A nightly job counting keys that appear in more than one partition is one grouped scan over recent partitions, and it converts a silent overcount into a page. State what it costs to run and what it fires on.
  4. Buy the cheap half of the real fix immediately: extend partition retention so the dedup horizon exceeds the producer's maximum retry window plus the longest replay you intend to support. That reframes retention as a correctness parameter rather than a storage cost, which is the sentence you need on record before someone optimises the bill.
  5. Make repayment mechanical instead of aspirational: a dated entry with a named owner, plus a threshold that pulls the date forward — first detector hit above N events, or first customer dispute. Debt with a trigger gets paid; debt with only a date does not.
  6. Answer the second half honestly by naming what you would refuse under identical pressure: the sealing path, because a sealed row is frozen and a wrong number there stops being a bug and becomes an adjustment line, a dispute and an audit question.
Follow-up
  • The detector fires on forty duplicate events for one tenant, and two of their invoices have already sealed. What happens next?
  • Whom did you tell that the billing numbers had a known hole, and in what words?
  • Finance asks you to cut storage by shortening partition retention. What do you say, and to whom?
  • 01

    Describe a time you took full ownership of a project from ideation to launch.

  • 02

    How do you handle ambiguity when the requirements for a feature are not fully defined?

  • 03

    Metered billing must be on in three weeks. usage_event is partitioned daily, so its unique index must include the partition key and deduplicates only within a day: a producer retry that crosses midnight, or a replay run a week later, gets through. A cross-partition dedup store is two weeks you do not have. Describe shipping with debt you named in advance: what you shipped, what you wrote down, the detector you added, the trigger and date for paying it off, and what you would have refused to ship under the same pressure.

PracHub interview preparation framework ↗
Is this an official Giga interview guide?

No. It is PracHub's own research and practice material for the Software Engineer role at Giga. Rounds and questions reflect what candidates have reported, not a process Giga has published, and they change over time. Confirm the current format and scope with your recruiter.

PracHub interview research ↗
How difficult is the technical interview?

The difficulty is considered average to high, primarily due to the pace. The challenge is not necessarily the complexity of the algorithms, but the speed at which you are expected to produce working, clean code.

PracHub interview research ↗
Does Giga value academic pedigree?

While technical skill and experience are paramount, the team does look for candidates with strong academic backgrounds from top-tier engineering programs.

PracHub interview research ↗
What is the culture like at Giga?

It is a high-ownership, fast-paced environment. You will be given significant autonomy, which means you are expected to be self-driven and proactive in your communication.

PracHub interview research ↗
How long does the process take?

The process is designed to be efficient to match the startup pace. While it can vary, most candidates move through the stages within a few weeks.

PracHub interview research ↗
Sources & methodology 3 sources ↗

Official role evidence, timestamped platform data and clearly labeled preparation advice.