REAL-TIME AI STEALTH COPILOT FOR TECHNICAL INTERVIEWSREAL-TIME AI STEALTH INTERVIEW COPILOT
The Only 100% Undetectable AI Live Assist with Senior+ Maturity Supporting All New Technical Categories Tested by Top Companies












HOW IT WORKS
Build on every file you opened, not just the last screenshot
Animated diagram. The prompt, every file and line you view or edit, and what is said in the discussion flow into one memory as you work. An arrow connects that memory directly to premium models, and the answer comes back as the kind of work the interview asked for.
Every file you view
Every line of code
Every requirement
Persistent contextual memoryContext builds as the session progresses
Livedisputes.pyline 20 edited
1–30lines read
loans.pyline 13 edited
1–24lines read
2 parts · 2 files · 54 lines · 2 edits · 2 notes
Claude Opus 5.5
GPT-5.6 Sol
Coding · part 2 of 2
WE'RE BUILT DIFFERENT
The real software engineer interview is no longer a single leetcode prompt — it contains rounds with multiple files or parts, changing requirements, AI code craft sessions, and code reviews all while watching your screen.
See how AI changed modern software interviews| What the interview demandsInterview capability | ![]() | Ultracode AI | Final Round AI | LockedIn AI |
|---|---|---|---|---|
1Single-part LeetCode-style questionsAlgorithms and data structures, one focused problem at a time | Yes | Yes, documented | Yes, documented | Yes, documented |
Live coding across many filesEach file you open is read and kept, not only the one on screen | Yes | No | No | No |
Context that survives every file switchCode, edits and requirements stay for the whole session | Yes | No | No | No |
Multi-part problems that keep evolvingEach new part builds on the code and rules before it | Yes | No | No | No |
2Structured workspace, not a chat threadApproach, code, complexity and tests in fixed places | Yes | No | No | No |
System-design diagrams & flowsExplore the architecture and trace each flow | Yes | No | Not confirmed: Screen reading and design guidance documented; generated diagrams and interactive flows not confirmed | Not confirmed: System-design frameworks documented; generated diagrams and interactive flows not confirmed |
Live AI suggestionsAnswers as the conversation unfolds | Yes | Yes, documented | Yes, documented | Yes, documented |
3Completely 100% UndetectableVerified stealth features | Yes | Yes, documented | Yes | Yes |
Undetectable by the browser | Yes | Yes, documented | Not stated | Yes |
Invisible in the Dock | Yes | No | Not stated | Yes |
Invisible to screen share | Yes | Yes, documented | Yes | Yes |
Invisible to the tray | Yes | No | Not stated | Yes |
Unidentifiable in Activity Monitor | Yes | No | Not stated | Yes |
Click-through | Yes | No | Not stated | Yes |
Published, signed test evidence | Yes | No | No | No |
4Live Debugging across filesThe failure traced to the file that causes it | Yes | No | No | No |
Multi-file PR review with inline commentsEach finding pinned to its line, across six checks | Yes | No | No | No |
Bugs that span files | Yes | No | No | No |
Design issues | Yes | No | No | No |
Missing tests and coverage | Yes | No | No | No |
API ergonomics | Yes | No | No | No |
Backwards compatibility | Yes | No | No | No |
Error handling | Yes | No | No | No |
| Price USD | View plans | $1,799 | $150/month | $1,999 |
✓ Documented · × Unsupported or not confirmed · – Not confirmed in the sources checked
Final Round AI and LockedIn AI item 2 sources were reviewed October 9, 2026. This is a public-documentation comparison, not hands-on testing.
1 Memory for the whole interview
You build the first part. Open another file. Add a new rule. Then the interviewer asks about an edge case that touches all three. HeapSeek keeps the code, edits and requirements you’ve already shown it, so the next answer builds on your work.
The hard follow-up needs the whole interview
Screenshot-only context
Available to this answer
The reservation code and its one-seat rule are both visible.
The current frame doesn’t include the ownership check you built in Part 1.
The payment handler alone doesn’t show how holds expire or who owns the seat now.
Persistent session memory
Available to this answer
Claim the seat atomically. Keep the winning reservation ID for the next part.
Release only the seat still owned by that expired reservation.
Use the reservation ID and expiry check already built. An expired hold must never confirm someone else’s seat.
Same follow-up. The difference is everything that came before it.
2 Undetectable by design
Global Shortcut Isolation Test
Native macOS shortcuts work at the OS level, keeping your interview window in focus. HeapSeek handles the shortcut’s main key before it reaches the browser or editor
Hidden from all capture and record pipelines at launch
No Dock icon and no ⌘‑Tab entry
No menu-bar (tray) item
Disguised as a nameless process with no identifiable icon
Live session clicks pass through overlay without taking window focus
No main key event ever reaches the browser/editor
3 Clarity under pressure
The interviewer points at one part of the code and waits. A chat reply makes you reread it to find that part. HeapSeek numbers every step and pins its reasoning to the lines it explains.
Spend the moment explaining, not searching
Other AI copilots

✦Sure! Let’s walk through the solution step by step. First, to make sure we’re aligned on the problem: we’re given an encryption key that maps each character to a short code, and we need to implement both encrypt and decrypt, where decrypt returns every word from the supplied word list whose encryption equals the given ciphertext.
Before the code, a quick note on loading the words. The list comes from a remote file, so fetching it on every call would be wasteful. A common approach is to wrap the loader in functools.lru_cache, so the request happens once and later calls reuse the result. This matters because decrypt may be called many times in a row.
For encryption, we iterate over the plaintext and look up each character in the key. If a character is missing we return None, otherwise we concatenate the mapped values and return the resulting string. Here is one way to put it all together:
def encrypt(key, plaintext):
pos = ""
for ch in plaintext:
if ch not in key:
return None
pos += key[ch]
return pos
def decrypt(key, ciphertext):
plaintexts = set()
for word in load_word_list():
word = word.strip()
if encrypt(key, word) == ciphertext:
plaintexts.add(word)
return plaintexts
Now, for decryption, it might be tempting to invert the mapping, but that gets ambiguous because several plaintexts can produce the same ciphertext. A simpler idea is to go forward instead: take each candidate word from the cached list, strip the trailing newline, encrypt it with the key and compare the result with the ciphertext. If they match we add the word to a set, since more than one word can match and we don’t want duplicates.
In terms of complexity, encrypt is O(L) for a word of length L, and decrypt runs encrypt once per word, so it is O(W·L) overall for W words, plus O(M) extra space for the M matches we keep. The cache adds O(W) memory for the list itself, which is usually fine.
A few edge cases worth mentioning to your interviewer: an empty ciphertext, characters that are not in the key, words with trailing whitespace, and an empty word list, in which case we simply return an empty set. You may also want to point out that the loader could fail, so in production code
Encrypt each candidate word and keep the exact matches
Load once and reuse it for every lookup
Join the character codes from the key
Collect matching words in a set
def decrypt(key, ciphertext):Encrypt each word, compare it with the ciphertext, and collect every match in a set
matches = set() for word in load_word_list(): word = word.strip() value = encrypt(key, word) if value == ciphertext: matches.add(word) return matches def encrypt(key, plaintext): if any(ch not in key for ch in plaintext): return None return "".join(key[ch] for ch in plaintext)Encrypt each of W words of length L
The M matching words kept in the set
Key: a → x, b → x, c → y · Words: ac, bc, ca
| Ciphertext | Expected matches |
|---|---|
xy | {ac, bc}Shared encoding |
yx | {ca}Single match |
zz | ∅No match |
Drag to compare
4 Precision in PR review rounds
Every finding pinned to its file and line
Debugging and review rounds grade what you catch. The costly bugs live between files, where one screenshot can’t look.
The interviewer asks “What would you flag before this merges?”
api/refunds.py
def create_refund(payment_id, amount=None): payment = payments.get(payment_id) ledger.debit(payment.account, amount or payment.amount)BlockerBug across files debit() now takes cents (ledger.py:17). This still passes dollars, so every refund is 100× too small.
notify_customer(payment, amount)HighDesign Ledger write and email share one handler. If the email fails, a retry refunds twice. Split the side effects.
return {"refund_id": refund.id} return {"refund": amount}BlockerBackwards compatibility Clients read refund_id today. Add the new field and keep the old one.
services/ledger.py
def debit(account, amount):def debit(account, cents: int):LowAPI ergonomics credit() takes dollars and debit() now takes cents. Use one unit across the module and name it in the signature.
if cents > account.balance: return NoneHighError handling An over-refund returns None and the API still answers 200. Raise so the caller can reject it.
account.balance -= centstests/test_refunds.py
def test_full_refund(): assert create_refund("p1")["refund"] == 50LowMissing tests Only the full refund is covered. Add a partial refund and one larger than the payment.
Made to think like you
Choose from a wide range of languages, coding styles, and solution preferences to tailor every answer to your needs
def max_depth(root): stack = [(root, 1)] depth = 0 while stack: node, level = stack.pop() if node: depth = max(depth, level) stack += [(node.left, level + 1), (node.right, level + 1)] return depth
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No one else offers it. Without it a copilot is useless for long code that was never captured in a single snapshot, for the multiple files you need to investigate, and for multi-part problems that build on your previous solutions.
No other platform offers more than LeetCode screenshot solving, and a long chat thread about a systems design helps no one. HeapSeek covers five rounds: coding, systems design, AI-assisted coding, debugging and code review.
Every answer comes from our agentic harness, which undergoes rigorous quality testing weekly against rubrics crafted by our team of UC Berkeley EECS graduates and ex-FAANG senior engineers, with combined decades of experience interviewing and understanding scoring guidelines.
We don’t just claim it. Every layer of evidence behind the testing is published on our verification page.
Open the Mac app, choose your interview type, and start a session. HeapSeek builds context from the screen and audio sources you enable. Use a global shortcut to solve or discuss a follow-up, with answers grounded in what’s been seen and said.
Yes. Lite covers algorithms, multi-file coding, multi-part problems, debugging, and system design. Pro adds AI Code Craft and Code Review rounds. Get the output each round needs: implementation steps, architecture and flows, or actionable findings beside the code.
Yes. Code, edits, and requirements already observed stay in the session’s context as you switch files. When Part 2 builds on Part 1, HeapSeek can build on that work too. You don’t need to recapture every earlier file for each follow-up. Before starting your next problem, you can easily clear the context memory from the Solve button’s options.
HeapSeek runs on Apple Silicon Macs with macOS 14 or later and an internet connection. It reads what you show on screen, so you can work in browser editors or desktop IDEs alongside your call. See our verification page for tested configurations.
HeapSeek uses macOS capture exclusion to keep its window out of supported screen shares and recordings. It also stays out of the Dock, menu bar, and app switcher, with native shortcuts that keep your editor in focus. Check the published tests and signed evidence for coverage.
Every programming language. By default HeapSeek dynamically uses the language your IDE is set to, read straight off your screen, so there is no configuration to worry about. If no language can be detected for a coding assessment, your default preference applies: choose from 11 backend languages (Python, Java, C++, C#, Go, TypeScript, JavaScript, Ruby, Rust, Kotlin and Scala) and 2 frontend languages (TypeScript and JavaScript) in Settings.
Yes. Set your preferred backend and frontend languages, then choose iterative or recursive approaches, comment detail, naming style, and comprehensions or explicit loops. Pro also includes personal notes for each interview type. Get solutions that are easier for you to read, explain, and extend.
Every new account gets 3 Solve Tokens once, with no credit card required. Use them for screenshot solves or interview-question unlocks, and explore the coding and system-design demos for free. Live copilot sessions require Lite or Pro. Try HeapSeek free.
Yes. Lite is for coding and system-design preparation. Pro adds AI Code Craft, Code Review, personal notes, longer sessions, and more Solve Tokens. Both offer monthly or three-month billing, so you can choose the term that fits your interview season. Compare plans.
Yes. The Question Bank organizes company-specific questions sourced from candidate reports. Lite includes five new question unlocks per week; Pro includes unlimited access throughout your plan’s duration. You can also subscribe directly to the Question Bank.
You choose the screen and audio sources and when to start or stop capture. Enabled sources may be sent to HeapSeek and its AI providers before you request an answer. Session content can be stored for history and service operation; our Privacy Policy explains retention and your choices.
All sales are final. Like every tool in this space, we have had accounts run a couple of interviews, land the job and ask for the money back the same week, so fees are nonrefundable, subject to the exceptions in our Terms and applicable law. That is also why every account starts with 3 free Solve Tokens and the full set of demos, so you can experience the entire live session flow before making a decision. Cancel renewal from your account at any time; paid access continues through the current billing period, or contact us with a billing question.