A crash is one of the more disruptive bugs a user can hit — the app was working, and then it wasn't. Sometimes it's obvious (a hard crash on launch), sometimes it's subtle (a freeze that never quite resolves, or a crash only some users report). We reproduce it, trace it to the actual failure point, and fix the cause — not just catch the error and move on.
1:1 Debugging Support · Fixed-Price & Hourly Options · Fast Turnaround
This Is For You If...
You're a founder and your app crashes right when someone tries to use it for the first time
Your team is getting crash reports from users and can't reproduce it internally
You're a student or freelancer staring at a stack trace that doesn't make sense
The app freezes instead of crashing outright, and you can't tell what's actually stuck
Something crashed after an update, and it worked fine the version before
Self-Diagnostic Checklist
Ask Yourself | What It Suggests |
Does it crash every time, or only sometimes? | Consistent crashes are usually faster to isolate; intermittent ones need a trigger pattern |
Does it crash on launch, or after a specific action? | Narrows down whether the issue is in startup/initialization or in a specific feature |
Do you have a stack trace, crash log, or error message? | The exact failure point is usually visible in the trace, even if the cause isn't obvious yet |
Did this start after an update, deploy, or dependency change? | Regressions are usually traceable to a specific recent change |
Does it crash outright, or does it freeze/hang without an error? | These point to different classes of problem and need different diagnostic approaches |
Is this affecting all users, or only some (specific devices, browsers, data)? | Partial patterns often point to something specific about that environment or input |
Runtime & Crash Errors We Fix
Fix App Crashes on Launch / Startup
When your app crashes on startup, won't launch, or crashes immediately on open, the cause is almost always in initialization — something failing before the app finishes loading. We isolate exactly what's breaking during startup and resolve the startup crash without guessing through your entire init sequence.
Fix Unhandled Exception / Uncaught Error Crashes
An unhandled exception error, uncaught exception, or unhandled promise rejection means something threw an error nothing was set up to catch. We trace the uncaught error crash back to its actual origin and fix both the immediate cause and the missing error handling around it.
Fix Null / Undefined Reference Errors
"Cannot read property of undefined," a null reference exception, "undefined is not a function," or a NullPointerException — these all mean your code expected something to exist that didn't. We find exactly where that assumption broke down and fix the underlying logic, not just add a null check that hides the real issue.
Fix App Freezing / Unresponsive / Hanging
When the app freezes, the page is unresponsive, or you're getting a "script not responding" message, the app hasn't necessarily crashed — it's just stuck. We identify what's blocking execution (a long-running process, a deadlock, an infinite loop) and get it responsive again.
Fix "White Screen of Death" / Blank Screen Errors
A white screen of death, a blank screen app crash, or an app that just shows a blank page usually means a rendering failure happened silently. This is especially common with white screen React/app issues where an error during render leaves nothing on screen and no visible message. We find the silent failure and surface what actually broke.
Fix Server Crashes / Process Exits Unexpectedly
A server crashed unexpectedly, a Node process exited, or a backend that keeps crashing points to an unhandled failure on the server side — often something that only surfaces under specific conditions. We diagnose the backend crash and the condition that triggers it.
Fix Type Errors at Runtime
"TypeError is not a function," a runtime type error, a type coercion crash, or an unexpected type error means your code received a different type of value than it expected. We trace where that mismatched value actually came from, not just where it failed.
Fix Crash After Update/Upgrade
If your app crashed after an update, broke after upgrading, or worked before the update and stopped after, this is a regression after upgrade — something in the new version changed behavior your code depended on. We isolate exactly what changed and adapt your code accordingly.
Fix Async / Race Condition / Deadlock Crashes
A deadlock error, a race condition crash, an async function crashing the app, or a blocked event loop are some of the hardest crashes to reproduce because timing is the cause. We use the right diagnostic approach for concurrency issues rather than treating them like a normal bug.
Fix Segmentation Fault Errors
A segmentation fault, segfault error, core dumped message, or SIGSEGV crash means your program tried to access memory it shouldn't have. We trace the exact memory access causing the fault, which usually requires closer, lower-level debugging than a typical application bug.
Fix Stack Overflow Errors
A stack overflow error, "maximum call stack size exceeded," or a recursion crash almost always points to unbounded or incorrect recursion. We find where the recursion fails to terminate and fix the base case or the logic driving it.
Fix Index Out of Range / Array Errors
An index out of bounds error, array index error, Python's IndexError, or an out of range exception means your code accessed a position in a collection that doesn't exist. We trace where that index came from and why it exceeded the actual data.
Fix File Not Found / I/O Errors
A file not found error, ENOENT error, FileNotFoundError, or a general I/O exception crash points to a mismatch between what your code expects on disk and what's actually there. We resolve the path, permission, or timing issue causing the mismatch.
Fix Network/Connection Timeout Crashes
A connection timeout crash, "network request failed," ECONNREFUSED, or a socket hang up error means a network call didn't behave the way your code assumed it would. We fix both the immediate crash and the missing handling for unreliable network conditions.
Fix Permission-Denied Runtime Errors
A permission denied error, EACCES error, access denied runtime crash, or insufficient permissions error means your app tried to do something the environment won't allow. We identify exactly what permission is missing and where, rather than suggesting broad, insecure permission changes.
Fix Out-of-Memory / OOM Killed Crashes (Runtime)
A process killed by OOM, an out of memory runtime crash, an app killed by the system, or a memory exhausted crash means your app used more memory than it was allowed. We identify what's actually consuming that memory rather than just recommending a bigger instance.
Fix Encoding / Unicode / Locale Crashes
A Unicode decode error, encoding error crash, charset mismatch bug, or a crash from non-ASCII characters is a narrow but genuinely frustrating category — often triggered by specific input your testing never covered. We find the specific encoding mismatch and fix it at the source.
Fix Third-Party SDK/Library Crash Errors
If your app crashes after SDK integration, a specific library is causing a crash, or you're seeing an SDK initialization crash, the cause is often outside your own code but still your responsibility to work around. We isolate whether it's a misuse of the library or a genuine issue in it, and fix accordingly.
Fix Crash Reports from Sentry/Crashlytics/Log Analysis
Already have a crash report from Sentry or Crashlytics but can't make sense of it? We read the stack trace, cross-reference it with your code, and turn a raw crash log into an actual fix — useful when you have the data but not the time or experience to interpret it.
Fix Mobile App Crashes (ANR / iOS Crash Logs)
For teams building mobile apps: an ANR (App Not Responding) error, an iOS crash log, or an app that's simply force closing on Android or iOS follows different diagnostic patterns than web or backend crashes. We work directly from your platform's native crash logs to resolve it.
Don't see your exact crash listed above? Send us what you're seeing — most crashes fall into a variation of one of these categories.
What We Need From You
What to Share | Why It Helps |
The stack trace, crash log, or error message | The exact failure point is usually visible here, even if the cause isn't obvious |
Steps to reproduce it, if known | Cuts diagnosis time significantly, especially for intermittent or timing-related crashes |
Whether it happens every time or only sometimes | Determines the diagnostic approach — consistent crashes are isolated differently than intermittent ones |
What changed recently (an update, a deploy, new code) | Regressions are usually traceable to a specific recent change |
Which environment it happens in (browser, OS, device, server) | Environment-specific crashes often point to something not present elsewhere |
Any crash reporting tool output (Sentry, Crashlytics, etc.) | Saves us from re-instrumenting something you may already have data for |
Common Mistakes to Avoid
Instinct | Why It Doesn't Help | Do This Instead |
Wrapping the crashing code in a try/catch without understanding why it fails | Suppresses the crash but hides the actual bug, which often resurfaces elsewhere | Understand the root cause before deciding how to handle it |
Adding a null check wherever "undefined" errors show up | Treats the symptom instead of the reason the value was ever undefined | Trace back to why the expected value wasn't there in the first place |
Assuming a crash after an update is a bug in the new version, not your code | Sometimes true, but often the new version simply exposed an existing assumption in your code that no longer holds | Check the changelog for what actually changed in behavior, not just assume it's broken |
Increasing memory or timeout limits to avoid OOM or timeout crashes | Delays the crash rather than preventing it, especially as usage grows | Identify what's actually consuming excessive memory or time |
Restarting the app/server repeatedly as the primary fix | Masks a recurring issue instead of resolving it | Diagnose why it's crashing, especially if the crash keeps recurring |
Debugging a race condition by adding random delays | Can mask the symptom without fixing the actual timing/ordering issue, and often breaks again under different load | Identify and fix the actual race, not just slow it down enough to hide it |
How It Works
Step | What Happens |
1. Share the crash details | Send the stack trace, error message, or crash report, plus steps to reproduce if you have them |
2. We reproduce the crash | We confirm the failure ourselves before proposing a fix, especially important for intermittent or environment-specific crashes |
3. We trace it to the root cause | We identify the actual failure point, not just where the error surfaced, since these are often different lines of code |
4. We fix it and verify it holds | The fix is tested against the actual crash scenario, including repeated runs for intermittent issues |
5. We explain what caused it | You get a plain-English explanation of the root cause, so the same crash doesn't resurface in a different form |
Why Codersarts
Crashes range from obvious to nearly impossible to reproduce, and treating them all the same way wastes time. We match the diagnostic approach to the type of crash — a null reference error gets traced differently than a race condition, and a mobile ANR gets read differently than a server process exit. We've worked through crash logs, stack traces, and "it only happens sometimes" reports for founders who needed it fixed before users noticed, and teams debugging issues that only show up in production.
Turnaround Time
Most crashes with a clear stack trace or error message are diagnosed within a few hours. Consistent, reproducible crashes are typically resolved same-day. Intermittent or environment-specific crashes may take longer to isolate and are scoped with a clear plan once we understand the pattern.
FAQ
Question | Answer |
I don't have a stack trace, just a description of what happened — can you still help? | Yes, though a stack trace or error message speeds things up significantly. We can also help set up crash logging if you don't have it yet. |
The crash only happens for some users and I can't reproduce it — is that a problem? | It's more challenging, but this is a common and solvable scenario — we'll work with whatever pattern data you have (device, browser, input) to narrow it down. |
Do you work with crash reporting tools like Sentry or Crashlytics? | Yes — if you already have crash reports from these tools, send them over and we'll work directly from that data. |
Do you handle mobile app crashes (iOS/Android), not just web? | Yes, if mobile crash debugging is relevant to your project — native crash logs and ANRs are read differently than web crashes, and we work with both. |
Is this confidential if it's for a work project? | Yes. We don't contact your employer or client, and an NDA is available on request. |
What if the crash comes back after your fix? | We test against the actual crash scenario before handing it back. If it resurfaces, follow-up is included as part of the engagement. |
Related Services
Compilation & Build Errors
Logic & Functional Bugs
Memory, Performance & Resource Bugs
Intermittent & Hard-to-Reproduce Bugs
App Crashing Right Now?
Don't keep guessing at the cause. Send us the stack trace or error message and get a diagnosis before you lose more time.